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This is a difficult question because there are pros and cons to saving him. His rescue took a huge financial, physical, and mental toll on everyone who was working to save him. If it were me, I don't think I would have wanted to fight that long to come home, it would have been easier to end it and save everyone the trouble. Many other projects were put on hold. It costed millions of dollars. BUT his story benefitted many people to come from what he learned by being and living on Mars for so long. What he did was a huge step for science and space travel. So this is a hard question and does not really have a solid answer.

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When I hear G force I think of the ride at the fair that is shaped like a space ship and you stand against the wall and it spins so fast that you can't move because of the force. It feels so weird and makes me kinda nauseous so I could not imagine the real force in a space ship like Watney would have felt.

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https://youtu.be/Lrle0x_DHBM

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Earth, Wind & Fire - Let's Groove (Official HD Video)

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I think that I personally would say that yes, his survival was worth what NASA went through. However, as readers, we get attached to the character, we see his side, and we are rooting for him. NASA and the rest of the world wouldn't get to see what we got to see in a real life situation. If this were to happen in real life of course I would say that yes, his survival is worth it, but I do have to admit I would be a bit frustrated. Do we go to these extents for people on earth in life or death situations? No, we don't. So I would say yes his life is worth it, but I would hope that people are coming together to help one person would spark something in us to help each other more often.

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They prepare people on how to not go unconscious while exposed to G-forces.

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I really just love being with my immediate family on Thanksgiving. Christmas and New Years is our extended family holiday, so Thanksgiving is our "us" holiday. In 2019, I went to NYC to be in the Macy's Parade for Thanksgiving, and it was the only time I had spent Thanksgiving without my family. I am very thankful for the experience and opportunity to be in the parade, but it made me so much more thankful for to be with my family on Thanksgiving in the years since.

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This website says that when Schiaparelli was naming the dark and light spots on Mars he named them "canali" which got misinterpreted for canals. Since canals are man made structures, people then thought that he had discovered life on Mars.

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In the 1800s, observatories with larger and larger telescopes were built around the world. In 1877, Giovanni Virginio Schiaparelli (1835-1910), director of the Brera Observatory in Milan, began mapping and naming areas on Mars. He named the Martian "seas" and "continents" (dark and light areas) with names from historic and mythological sources. He saw channels on Mars and called them "canali." Canali means channels, but it was mistranslated into "canals" implying intelligent life on Mars. Because of the then recent completion of the Suez Canal in 1869 (the engineering wonder of the era), the misinterpretation was taken to mean that large-scale artificial structures had been discovered on Mars. The importance of canals for worldwide commerce at that time without a doubt influenced the popular interest in "canals" on Mars.

In 1894, Percival Lowel, a wealthy astronomer from Boston, made his first observations of Mars from a private observatory that he built in Flagstaff, Arizona (Lowell Observatory). He decided that the canals were real and ultimately mapped hundreds of them. Lowell believed that the straight lines were artificial canals created by intelligent Martians and were built to carry water from the polar caps to the equatorial regions. In 1895, he published his first book on Mars with many illustrations and, over the next two decades, published two more popular books advancing his ideas.

From a good ground-based telescope like the one that Percival Lowell built, Mars looks more like this animation!

The War of the Worlds cover

Lowell's theories influenced the young English writer H.G. Wells, who in 1898 published The War of the Worlds. In this novel, Wells created an invasion of Earth by deadly aliens from Mars and launched a whole new genre of alien science fiction.

In 1911, "A Princess of Mars", the first of eleven science fiction novels by Edgar Rice Burroughs, was published. Burroughs used Schiaparelli's names for regions on the planet and gave his Martians green skin.

On Halloween in 1938, Orson Welles and The Mercury Theater on the Air broadcast a radio version of The War of the Worlds. The story, presented as a series of "live" news bulletins, panicked thousands of listeners who believed that America was being attacked by hostile Martians.

Most experienced astronomers never saw the Martian "canals" and for a good reason. We now know that they never existed! The network of crisscrossing lines covering the surface of Mars was only a product of the human tendency to see patterns, even when patterns do not exist. When looking at a faint group of dark smudges, the eye tends to connect them with straight lines. This has been demonstrated by many laboratory and field experiments.

Questions to think about:

How are the images from ground-based observatories different from those made with small telescopes?

What new information and speculations can you make about what Mars might be like from these images?

SOURCE: Aerospace Scholars - An Educational Outreach Program Between NASA's Johnson Space Center & The State of Texas

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NASA - National Aeronautics and Space Administration

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In the 1800s, observatories with larger and larger telescopes were built around the world. In 1877, Giovanni Virginio Schiaparelli (1835-1910), director of the Brera Observatory in Milan, began mapping and naming areas on Mars. He named the Martian "seas" and "continents" (dark and light areas) with names from historic and mythological sources.

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ABBA - Dancing Queen (Official Music Video)

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I think that I just assumed that if the HAB was breached there would be no way to get it "unbreached" for lack of better words. It was cool to listen to the things he had to do to fix it, and all of the components that went into it. It was also very cool to watch him fix it in the movie, but also weird because he relied on that patch to hold the HAB together.

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This video explains how RTGs work and why we cannot always use Solar Panels.

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Common Themes Among Agatha Christie Novels

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Common Themes Among Agatha Christie Novels

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One common theme among Agatha Christie Novels is Feminism. I think that this goes hand in hand with The Martian because even though I wouldn't say that feminism is a theme of the book, the mission commander is a woman. I think that that is very thoughtful of the author.

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This Article has a really awesome picture of the routes to mars and where spacecrafts are in trips to mars. The book talks about orbits matching up, and the picture provides a good visual of that.

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The cruise phase begins after the spacecraft separates from the rocket, soon after launch. The spacecraft departs Earth at a speed of about 24,600 mph (about 39,600 kph). The trip to Mars will take about seven months and about 300 million miles (480 million kilometers). During that journey, engineers have several opportunities to adjust the spacecraft's flight path, to make sure its speed and direction are best for arrival at Jezero Crater on Mars. The first tweak to the spacecraft's flight path happens about 15 days after launch.

Track the Spacecraft's Flight

: Get a "live look" at the Mars 2020 spacecraft in flight, with this interactive visualization based on real data. Eyes on Perseverance View the full experience ›

The Trip to Mars

Engineers on Earth keep close tabs on the mission during cruise. Major activities include:

Checking spacecraft health and maintenance

Monitoring and calibrating the spacecraft and its onboard subsystems and instruments

Performing attitude correction turns (slight spins to keep the antenna pointed toward Earth for communications, and to keep the solar panels pointed toward the Sun for power)

Conducting navigation activities, such as trajectory correction maneuvers, to determine and correct the flight path and train navigators before atmospheric entry. The last three correction maneuvers are scheduled during approach.

Preparing for entry, descent, and landing (EDL) and surface operations, a process which includes tests of communications, including the communications to be used during EDL.

The mission is timed for launch when Earth and Mars are in good positions relative to each other for landing on Mars. That is, it takes less power to travel to Mars at this time, compared to other times when Earth and Mars are in different positions in their orbits. As Earth and Mars orbit the Sun at different speeds and distances, once about every 26 months, they are aligned in a way that allows the most energy-efficient trip to Mars.

Perseverance's Route to Mars

Perseverance's Route to Mars: An illustration of the route the Mars 2020/Perseverance spacecraft takes to get to Mars. Full image and caption ›

Fine-Tuning the Flight Path to Mars

During the cruise phase, engineers have five opportunities (plus one backup maneuver and one contingency maneuver) to adjust the flight path. During these trajectory correction maneuvers, engineers will calculate the spacecraft's location and command eight thrusters on the cruise stage to fire for a specific amount of time needed to tweak the path.

The maneuvers are very important because years of careful planning led to selection of Jezero Crater as the landing site on Mars, and fine-tuning the flight path ensures that the spacecraft will enter the Mars atmosphere at just the right spot to land inside Jezero crater.

The final 45 days leading up to the landing make up the approach phase. This phase primarily involves navigation activities and getting the spacecraft ready for Entry, Descent and Landing. This is when the final three trajectory correction maneuvers may be performed, if needed.

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The cruise phase begins after the spacecraft separates from the rocket, soon after launch. The spacecraft departs Earth at a speed of about 24,600 mph (about 39,600 kph). The trip to Mars will take about seven months and about 300 million miles (480 million kilometers).

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Loved this book and loved this class!

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Though I'm a science major, I'm a humanities person at heart. I think saving Mark's life was definitely worth all the risk that NASA took because one life can make all the difference. Mark did what no other human had ever done before and proved that it was possible to survive on Mars with little to no help from the outside world, and the knowledge/experience Mark brought back to earth holds an incredible amount of value.
Although NASA spent millions for materials and alterations to planned missions, they gained much more during the journey. The JPL team, NASA, and the Hermes crew can say they effectively united the entire world to save one man. NASA internationally communicated with and made plans with other space programs in order to save Watney, and those communication lines will now be open to help NASA more in the future. The Hermes crew sacrificed more time away from their families, but was ultimately reunited with Mark who was basically family to them. The mission to save him was dangerous but the risk was worth taking in the end because it was always going to be a success (I don't think Weir would have written a sad ending).

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Han Solo talks about "making the jump to light speed" on the falcon. Though it is fun to imagine going 0-100 mph in a matter of seconds, his quote implies an instantaneous acceleration to 186,000 miles per second. That kind of g force would literally cause his body to disintegrate, so it would be impossible for him to "jump to light speed". The human body can survive 9 gs for a few seconds, and it would still take Han Solo 19 days at 9 gs to reach HALF the speed of light. Again this confirms he would be dead before he could "make the jump to light speed"

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Editor's Note: The following is an excerpt from the 1999 book The Science of Star Wars by Jeanne Cavelos.
Han Solo talks about making the "jump to light speed." If the Millenium Fal con is somehow jumping to light speed, it implies a nearly instantaneous acceleration. The Falcon might be traveling along at 50 miles per hour, and then suddenly it's traveling at 186,000 miles per second. Let BMW try to beat that acceleration! It's no problem for Han to accelerate the Falcon from zero to 60 miles per hour in five seconds. Inertia will push him slightly back in his seat. But accelerating from zero to 186,000 miles per second in five seconds will push Han back so forcefully that he'll become a splat on that fine vinyl upholstery.

The speed of light is so fast, that to accelerate to it safely would take months! We measure acceleration in g's, with one g equal to the acceleration caused by Earth's gravity-the acceleration of falling objects on Earth. The reason we measure acceleration in terms of gravity is because the two have the same effect. The gravitational force on an object is equivalent to the inertial force on an object undergoing a comparable acceleration. Just as gravity pushes you down against the Earth, inertia pushes you back against your seat.

We experience higher or lower g forces when we are rapidly changing speeds or directions. Normal humans can withstand no more than 9 g's, and even that for only a few seconds. When undergoing an acceleration of 9 g's, your body feels nine times heavier than usual, blood rushes to the feet, and the heart can't pump hard enough to bring this heavier blood to the brain. Your vision narrows to a tunnel, then goes black. If the acceleration doesn't decrease, you will pass out and finally die. The Air Force's F-16 can produce more g's than the human body can survive. We're forced to limit the acceleration of planes and spacecraft to a level humans can survive.

If we need to accelerate for extended periods, the level we can withstand is even lower. We can withstand 5 g's for only two minutes, 3 g's for only an hour. For the sake of argument, though, let's try to tough it out at 3 g's for a little longer. For Han to take off from Mos Eisley and accelerate at 3 g's to half the speed of light would take him two and a half months-hardly the makings of an exciting movie. Even at 9 g's, it would take him nineteen days to reach half the speed of light, though he'd be dead long before the ship reached that speed.

Since Star Wars ships are constantly undergoing rapid accelerations and decelerations, they must have found some way to solve this problem. Perhaps they have learned to manipulate inertia. Just eliminating it for a fraction of a second could allow a rapid, effortless acceleration, after which point inertia could return and the Falcon could cruise at a constant, high velocity.

Of course, the force that makes us stumble back as the subway car accelerates doesn't seem completely conquered on the Falcon. In The Empire Strikes Back, the Falcon's jump to hyperspace throws Artoo across the deck and into the open engine pit. Perhaps some of Han's "special modifications" need a tune-up.

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The Jump to Light Speed Is a Real Killer

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Editor's Note: The following is an excerpt from the 1999 book The Science of Star Wars by Jeanne Cavelos. Han Solo talks about making the "jump to light speed." If the Millenium Fal con is somehow jumping to light speed, it implies a nearly instantaneous acceleration.

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In today's society, many people would rather "wait for the movie" than read a novel. You are fortunate enough to have done both!

Discuss how the reading the book (and we read it carefully!) was beneficial. Some questions you might ask yourself include: What did you learn about reading for pleasure? Did participating in a book group help you enjoy the novel in a way that reading it alone could not? Would you read another Andy Weir book?

Now, think about the movie. In what ways did it differ from the book? Some questions you might ask yourself: Were these changes significant? Were they necessary for a visual representation of the book to become a Hollywood success?  Were you disappointed about what was left out? Did watching the movie enhance your reading of the book?

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First, just what was the cost to the Hermes crew, to JPL, to NASA, to Watney? Then, think about "was it worth it." Well, was it? Was it not? Why?

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The cost to save Mark Watney cannot be specifically measured the material cost is easy enough but you cannot really measure the data that would have been collected by the Chinese booster, or the Nasa booster that would have been used, however, pushing uncertainty aside I would estimate the cost of mark Watney's survival would be in the hundreds of Billions of Dollars do to the cost of the rockets, the cost of the maintenance involved with the extended mission the Hermes, the cost of the supplies, the cost of use of satellites over Mars. Again this is not accounting for potential loss in money that could have came as a result of scientific discovery.

In general, yes, morally speaking our society values life especially of important people like astronauts. Materialistically speaking, bringing someone home who has survived mars, helps our science, as well as provides a teacher who can increase the skill of other astronauts using the skills, he picked up granted his logs could have done that as well, but it is usually more effective to have the person teach it.

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Nasa has many ways to train astronauts for a lot of g's and no gravity ounce they get into space. the centrifuge is a great way to train for the g-forces associated with acceleration but, fewer people know about the 0g airplane that NASA used to use to train there astronauts for space flight. This plane travels straight up and then when at altitude it travels straight down giving the crew onboard a couple of minutes to experience 0g. Nasa also uses a massive pool that you may have seen on movies to train astronauts for 0g, however, this is not a completely accurate test because water  exerts drag, as well as other forces on objects that will not be in space.

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https://www.youtube.com/watch?v=yxxj73JCV4Q

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Seriously. Go watch Apollo 13 if you have time. It's an amazing movie based on Jim Lovell's book *Lost Moon*

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Apollo 13 Official Trailer #1 - Tom Hanks Movie (1995) HD

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Thanksgiving is an important holiday in The Martian. Watney talks about several times re: potatoes, gathering together, driving.

Share your own thanksgiving tradition and/or memories. It can be about the actual holiday of Thanksgiving or it can be about any other celebration in which you are moved to give thanks.

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My mom still loves this song, she used to play it for me when I was young

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Giovanni observed the planet for years but had to wait until 1877 when Mars was in opposition to make his famous observations of the canals. Two years later during the next opposition, his observations were confirmed by other scientists.
His work eventually let him to become a foreign member of the Royal Society in 1896.

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On March 14, 1835, Italian astronomer and science historian Giovanni Schiaparelli was born. He is remembered best for his observations of planet Mars, where he discovered a dense network of linear structures on the surface of Mars which he called "canali" in Italian, meaning "channels" but the term was mistranslated into English as "canals" indicating that the observed structures should be of artificial origin.

"Mercury on its axis turns like the Moon:
One side has lasting day, the other night;
One side in everlasting fire doth swoon;
While th'other hides forever from the light."
Giovanni Schiaparelli, (Originally in Latin; translated by Agnes Mary Clerke (1842-1907)) [7]

Early Years

Schiaparelli graduated in 1854 from the University of Turin in the engineering sciences of architecture and hydraulics. For some time he pursued private studies in astronomy, mathematics and languages. In 1856 he became a mathematics teacher at an elementary school in Turin. To become an astronomer, he studied from 1857 for two years at the Berlin Observatory under the then director Johann Franz Encke. Another year he worked at the Pulkovo Observatory under the direction of Wilhelm Struve. In 1860 Schiaparelli returned to Italy to take up a position as "secondo astronomo" at the Osservatorio Astronomico di Brera in Milan under Francesco Carlini.

The Planet Mars

Giovanni Schiaparelli devoted much of his time as a scientist to telescopic observations of planet Mars. In his initial observations, he named the "seas" and "continents" of Mars. These linear structures were close to the visibility limit of the then 30 to 50 cm telescopes and required special observation experience. During the planet's Great Opposition of 1877, he observed a dense network of linear structures on the surface of Mars which he called " canali " in Italian, meaning "channels" but the term was mistranslated into English as "canals". As we know, canals indicate artificial constructions, wherefore channels indicate natural configurations of the planetary surface. Only at the next Mars opposition in 1879 was her sighting confirmed by other astronomers.

"Rather than real channels of form to us more familiar, we must imagine soil depressions not very deep, extended in a straight direction for thousands of kilometers, over a width of 100, 200 kilometers or more. I have already pointed out once again that, lacking rain over Mars, these canals probably constitute the main mechanism with which water (and with it organic life) can spread on the dry surface of the planet ".
- Giovanni Schiaparelli, La vita sul planet Marte, extracted from booklet n° 11 - Year IV of the magazine Nature and Art, May 1895, Cap. I

The Martian Cannals

When the term was incorrectly translated, numerous research attempts were made about life on Mars as well as its conditions. The 'canals' became very popular and the result was a rise of hypotheses, and mad speculations on the possibilities of intelligent life on Mars. Theories about the 'Martians' established. The well known American astronomer Percival Lowell was known to be one of the greatest supporters of the canal-hypothesis.[ 4] He then spent a great time of his professional life attempting to find existing intelligent life on the planet. It was only in the 1910s after Lowell's death that scientists officially rejected the artificial-canal-hypothesis.

The War of the Worlds

However, the science fiction culture did not let go off the mystical canal theory and the 'possible' life on Mars inspired numerous writers like H. G. Wells' The War of the Worlds.[ 5] Later, with notable thanks to the observations of the Italian astronomer Vincenzo Cerulli, scientists came to the conclusion that the famous channels were actually mere optical illusions (line amplification by correlated irritation of adjacent visual cells). The last doubts were finally cleared in the 1960s, when Mariner 4 from the American Space Program photographed the surface with much higher resolution than Earth-based telescopes, confirming that there are no structures resembling "canals". However, about half of the Martian channels mapped by Schiaparelli and other astronomers are likely to correspond to actual canyons, linear terrain shadows, valley systems or crater chains.

Later Life

Schiaparellis' astronomical research also concerned Mercury, Venus, solar activity and the double stars. One crater each on the moon, Mercury and Mars was named after him. An observer of objects in the Solar System, Schiaparelli worked on binary stars, discovered the large main-belt asteroid 69 Hesperia on 29 April 1861, and demonstrated that the meteor showers were associated with comets. He proved, for example, that the orbit of the Leonid meteor shower coincided with that of the comet Tempel-Tuttle. These observations led the astronomer to formulate the hypothesis, subsequently proved to be correct, that the meteor showers could be the trails of comets.

Schiaparelli became a foreign member of the Royal Society on November 29, 1896. The famous fashion designer Elsa Schiaparelli was his niece. He died on July 4, 1910, in Milan, at age 75.

Andrew Coates,Looking for Life on Mars, [8]
References and Further Reading:

[1] Schiaparelli, Giovanni Virginio (1835-1910) Biography

[2] Schiaparelli and the "first Martians" at NASA

[3] The "Canals" of Mars: How Giovanni Schiaparelli Saw Tharsis

[4] Percival Lowell and the Search for Pluto, SciHi Blog

[5] H. G. Wells and the Shape of Thing to Come, SciHi Blog

[6] Giovanni Schiaparelli at Wikidata

[7] Sky and Telescope, March 2011, p. 33

[8] Andrew Coates, Looking for Life on Mars, Gresham College @ youtube

[9] "Schiaparelli, Giovanni Virginio". LexicoUK English Dictionary. Oxford University Press.

[10] G. V. Schiaparelli, J. G. Galle, J. B. N. Hennessey J. Coles, J. E. Gore, The Observatory, Vol. 33, p. 311-318, August 1910

[11] Works by or about Giovanni SchiaparelliatInternet Archive

[12] Timeline of notable Italian Astronomers via DBpedia and Wikidata

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Giovanni Schiaparelli and the Martian Canals - SciHi Blog

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On March 14, 1835, Italian astronomer and science historian Giovanni Schiaparelli was born. He is remembered best for his observations of planet Mars, where he discovered a dense network of linear structures on the surface of Mars which he called "canali" in Italian, meaning "channels" but the term was mistranslated into English as "canals" indicating that the observed structures should be of artificial origin.

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I don't have any family in Arkansas besides my parents, so usually for Thanksgiving we go to my family's good friends house, since she's a cook, and have Thanksgiving over there. That being said, my mom is very asian and so is our family's friend, so our thanksgiving is a little different than the traditional mashed potatoes, green beans and turkey. We of course have turkey, but we have different side dishes such as cabbage, rice, and this type of fried mashed potatoes (it's very hard to explain). Before we eat our meal, we all also say what we're thankful for.

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Thanksgiving is a holiday that started as a way to celebrate the Pilgrims and Indian getting along, and having a great feast with each other, and although we still celebrate that by having a large feast my Family tends to use it as a family day we always take that week off from work and school, and we just sit around and play family games, and invite family from out of state. This is usual for everyone; however, my family has some traditions coming from our Scandinavian heritage that are different from others. During Thanksgiving, we enjoy the things we have like family, and relies, despite the bad things that happen in life, we still very lucky to have what we have.

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The Hab breach on Mars was do to the constant use of the airlock it wore it down and eventually the seal broke. This is actually a massive problem facing modern mission ideas to both the moon and mars, not so much the overuse although that is also a problem for colonization, this problem extends to dust, both lunar, and Martian in both causes the dust is attracted to materials found in most space suits and material in tools and structures, this dust can erode material and affect mobility as well as eventually poking holes into space suits and some times of lightweight habs we might use.

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SETI mainly listens for alien life they did do a couple of proof of concept attempts to send out messages but were stopped by other scientists because of the risk to our species, I will not go into detail, but basically, the Fermi paradox says that since we are living towards the end of the age of star formation in our universe, that life has had a long time to grow and form intelligence and because of this we would expect to see someone who has colonized the majority of the galaxy but because we don't the question is where is everyone, one of the many potential answers to this paradox is the "Dark Forest" Solution which basically assumes that the competition of life is universal and that if people came to dominate there planet they are probably competitive and potentially hostile, this is an oversimplification I suggest looking into it yourself, but it has sparked a debate on weather we should broadcast ourselves to the universe in order to speed up communication with an alien species.

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Because of the limits of solar power as you get further from the sun, RTGs are the best way to get power. Allmost all of our outer solar system probes, as well as the voyagers, are powered by this method.

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Three RTG units, electrically parallel-connected, are the central power sources for the mission module. Each RTG is made up of a radioisotope heat source, a thermoelectric converter, a gas pressure venting system, temperature transducers, connectors, a heat rejecting cylindrical container, and bracketry. The RTGs are mounted in tandem (end-to-end) on a deployable boom as part of the MM.

The heat source radioisotopic fuel is Plutonium-238 in the form of the oxide Pu02. In the isotopic decay process, alpha particles are released which bombard the inner surface of the container. The energy released is converted to heat and is the source of heat to the thermoelectric converter.

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Three RTG units, electrically parallel-connected, are the central power sources for the mission module. Each RTG is made up of a radioisotope heat source, a thermoelectric converter, a gas pressure venting system, temperature transducers, connectors, a heat rejecting cylindrical container, and bracketry. The RTGs are mounted in tandem (end-to-end) on a deployable boom as part of the MM.

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Reflect on the letters Watney wrote to his Hermes crewmates? Why did he write what he wrote to each? What did this do (or maybe not do) for Watney emotionally? What might it have meant to his Hermes colleagues?

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This videos gorgeously portrays what the Apollo 13 astronauts saw as they were in orbit around the moon. They lost contact with earth and were in complete darkness for around 8 minutes I believe.

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Astronauts aboard the Apollo 13 spacecraft had survived an explosion and reduced oxygen before their next tricky venture, on April 14, 1970: a 25-minute pass by the far side of the moon, out of communication with Earth.

Now, you can see a portion of the Apollo 13 astronauts' view of the moon's far side, thanks to courtesy of NASA's Lunar Reconnaissance Orbiter (LRO).

LRO is optimized to zoom in on small targets on the surface of the moon. The spacecraft's results have been used for everything from identifying permanently shadowed water ice, for potential use in future human landing missions, to photographing Apollo landing sites from the 1960s and 1970s.

Related: 'Apollo 13' launching back into theaters anniversary (opens in new tab)

(Image credit: NASA Goddard/YouTube)

The Apollo 13 crew never had the chance to land on the moon. Their craft was en route to landing when an oxygen tank exploded in a service module on April 13, 1970, forcing mission planners to reroute with a backup plan. The astronauts, fortunately, were unhurt in the explosion. But the damage ripped out oxygen tank lines and damaged the command module spacecraft, called Odyssey. This module was designed to bring astronauts through Earth's atmosphere at the end of the mission.

NASA had to quickly figure out how to keep the astronauts alive for four days on the journey home, as they were not going to be landing on the moon. The agency directed the astronauts to power up the other, undamaged spacecraft on the mission - the lunar module Aquarius - and do several engine burns with that module's descent engine. The engine burns were needed to complete the astronauts' path through space, to loop around the moon and come back to Earth. (Doing a straight turn-around abort wasn't possible, because only Odyssey had a powerful enough engine to accomplish this, and that engine was assumed to be damaged in the explosion.)

With the astronauts already in such danger, going behind the moon added another layer of stress, because the crew was unable to communicate with Earth during that time. However, they came through OK, and this new, 4K LRO video shows, in stunning detail, several landmarks they would have seen on the far side of the moon.

In the video, you can see craters on the far side of the moon pop up along the horizon as the spacecraft flies above the 4.5-billion-year-old rocky satellite. The camera lingers for a while on a crater with a mountain at its center. And soon comes that special moment when Earth pops up above the horizon, so you can see home from the craft once again.

"This video uses data gathered from the Lunar Reconnaissance Orbiter spacecraft to re-create some of the stunning views of the moon that the Apollo 13 astronauts saw on their perilous journey around the far side in 1970," NASA's Goddard Space Flight Center said in a statement released with the YouTube video.

Goddard noted that the astronauts did not see landmarks whiz by as quickly as viewers do in the video. "All views have been sped up for timing purposes - they are not shown in 'real time,'" the center added.

Despite turning into a life-saving flotation device when it was meant to land astronauts on the moon, the Apollo 13 Aquarius lunar module performed incredibly well during the mission. The Apollo 13 astronauts - Jim Lovell, Fred Haise and Jack Swigert - made it home safely, with only minor injuries, despite living for four days in the spacecraft with little heat or water available. Lovell and Haise are still participating in public events, at ages 91 and 86, respectively; Swigert died of cancer in 1982, at age 51.

This April will mark the 50th anniversary of the Apollo 13 mission. The astronauts themselves will participate in events in New York state, Florida and Kansas during the month, and more appearances may be announced in the coming weeks.
Join our Space Forums to keep talking space on the latest missions, night sky and more! And if you have a news tip, correction or comment, let us know at: community@space.com.

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This stunning 4K video re-creates Apollo 13's perilous trip around moon

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Astronauts aboard the Apollo 13 spacecraft had survived an explosion and reduced oxygen before their next tricky venture, on April 14, 1970: a 25-minute pass by the far side of the moon, out of communication with Earth. Now, you can see a portion of the Apollo 13 astronauts' view of the moon's far side, thanks to courtesy of NASA's Lunar Reconnaissance Orbiter (LRO).

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https://www.youtube.com/watch?v=bHfrdQ8h2Pw

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I am a big holiday person and love spending them with my family. Thanksgiving for my family varies very year. Sometimes I would go hunting with my dad that morning and then come home for lunch, or sometimes we will just meet him at our deer camp that night. We always do thanksgiving lunch at my grammy's house and before my poppy passed we would do dinner at his house. Now we do dinner at my uncle's house usually. I hate that the old traditions have to change as we get older, but there are always new ones to make!

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My grandfather was a short, redheaded, wiry Irish man named James Oliver McGee. His nickname was Fibber, taken from the old radio show comedy Fibber McGee and Molly (1935-1959). Every Thanksgiving, my family would travel to the red clay fields of Marshall, OK for the holiday. My grandmother, Ruby, wasn't very pleasant, but my grandfather was a joy.  He would always give me a silver dollar when we visited and (in my child's mind) I was rich! Rich? No. In fact my family was always on the edge. When I was maybe 7, I remember going to the bank with my mother to deposit the coins into the family account. If not, we simply would not have eaten that week. I don't remember being angry or upset at losing my treasure. I just knew that this was how it had to be. I think about this experience this time of year and give thanks that I was able to help support my family's need. Food insecurity is real, folks.

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Giovanni Schiaparelli, Was an Italian Astronomer, He was born in the Kingdom of Sardina on March 14, 1835 before Italy unified in 1861.around the time the United States civil war was starting for reference.

Although, he started in Italy, a lot of his work was in the Germany.  His importance on Mars was that he made many observations with telescope on Mars, as a result, The crater was named after him in respect to the observations he made with telescopes and observatories.

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Department of Physics & Astronomy at Sonoma State University

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Giovanni Schiaparelli was born in Piedmont and studied hydraulic engineering and civil architecture at the University of Turin and then astronomy at the observatories at and . He worked at the Brera Observatory in Milan for forty years, all but the first two as director. Although a major observer of double stars, he is best known for his observations of solar system objects. In 1861 he achieved some fame for discovering the minor planet Hesperia. He made extensive studies, both observational and theoretical, of , determining from the shapes of their tails that there was a repulsive force from the sun. He showed that Venus and Mercury rotate very slowly, although he concluded, erroneously, that they were in synchronous rotation. He explained the regular meteor showers as the result of the dissolution of comets and proved it for the Perseids. Schiaparelli observed Mars over seven oppositions and named the "seas" and "continents". His observations of canali, mistranslated as canals, stimulated Percival Lowell to found his Arizona observatory and search for life on Mars. Schiaparelli also observed the other planets. Expert in both ancient and modern languages as well as religions, he took up the history of ancient astronomy after retiring from observing in 1900.

Presentation of Bruce medal

Other awards

French Academy of Sciences, Lalande Prize, 1868, 1890.
Government of Germany, Order Pour le Merite for Arts and Sciences, 1895.
Italian Society of Science, Gold Medal, 1868.
Royal Astronomical Society, Gold medal, 1872.

Biographical materials

All'astronomo G.V. Schiaparelli: omaggio 30 giugno 1860 - 30 giugno 1900 (M. Bassani, Milano, 1900). This book includes a biblography of his writings to 1900.
Abetti, Giorgio, Dictionary of Scientific Biography 12, 159-62.
Istituto lombardo-acc. scienze lettere, Milano & Osservatorio astronomico di Brera, Milano, Atti del Convegno per le celebrazioni del cinquantenario della morte di G. V. Schiaparelli, (Milano, 1960).
Bianucci, Piero, "Giovanni Virginio Schiaparelli," L'Astronomia 6 45-48 (1980).
Boccardi, Jean, "La Commémoration de Jean Schiaparelli," Revue Général des Sciences Pures et Appliquées 46, 379-82 (1935).
Botta, Luigi, l'Astronomo Giovanni Virginio Schiaparelli [includes extensive list of links, in Italian]
Brera Observatory (in Italian)
Cossavella, G. , L'Astronomo Giovanni Schiaparelli (Turin, 1914).
Doublet, E., "Le Centenaire de Giovanni Schiaparelli," and52, 82-86 (1936) [in French].
Fergola, E., et al, All'Astronomo G.V. Schiaparelli-Omaggio, 30 Giugno 1860-30 Giugno 1900 (Milan, 1900).
Gabba, Luigi, "Giovanni Schiaparelli e la storia dell'astronomia," Rendic. Seminar, Mat. Fis. Milano 2, 121-38 (1928).
Gabba, Luigi, Schiaparelli (La Scuola, Brescia, 194?).
Mazzucato, Michele T., "Giovanni Virginio Schiaparelli," .
Mazzucato, Michele T., "Giovanni Virginio Schiaparelli: Fonti per una ricerca," - includes timeline and bibliography (in Italian).
Mazzucato, Michele T., Giovanni Virginio Schiaparelli: Centenario della morte, 1910-2010 (Edizioni Tassinari, Firenze, 2010) [in Italian].
Panaino, Antonio & Guido Pellegini, eds., Giovanni Schiaparelli: Storico della Astronomia e Uomo di Cultura. Atti del Seminario di Studi Organizzato dall'Instituto Italiano per l'Africa e l'Oriente e dall'Instituto di Fisica Generale Applicata dell'Università degli Studi di Milano, (Osservatorio Astronomico di Brera, Milano, 1999).
Schiaparelli and His Legacy: Symposium: Milano, Oct 19-20, Torino Oct 21, 2010. On the Centenary of His Death.
Tenn, Joseph S., "Giovanni Schiaparelli: The Fourth Bruce Medalist," .
Zagar, Francesco, "Giovanni Schiaparelli nel Cinquantenario Della Morte ," Contributi dell'Osservatorio Astronomico di Milano-Merate. Nuova serie, n. 161 (Prem. Tipografia Succ., Milano, 1960).

Obituaries

Abetti, A. & G. , .
Aitken, Robert G., .
Bonacini, Carlo, Commemorazione Di Giovanni Schiaparelli (Società Tipografica Modenese, Modena, 1911).
Celoria, Giovanni, Giovanni Schiaparelli : brevi note commemorative (Tipo-Lit. Rebeschini di Turati, Milano, 1910).
Celoria, Giovanni, Scientia Rivista di Scienza 9, 169-185 (1911).
K[nobel], E. B., .
MacPherson, H.J.,Popular Astronomy 18, 467-74 (1910).
Sampson, R.A, Proceedings of the Royal Society A 86, 37-38 (1911-12).

Astrodictionary
Botta,Luigi, l'Astronomo Giovanni Virginio Schiaparelli (several)
Burchill, Shirley, The Open Door Web Site
CollectSpace, Postage stamp issued on centennial of death
Getty Images
Library of Congress: autographed drawing by Robert Kastor
Philosophy of Science Portal, 16 March 2009
Schiaparelli at age 30 from the book by G. Peyretti, Il sommo astronomo Virginio Giovanni Schiaparelli glorificato nella sua città natia. Brevi cenni a ricordo dellinaugurazione del monumento che ne eterna la gloriosa memoria - 15 novembre 1925 (Stab. Tip. Sociale, Savigliano CN, 1925), courtesy Michele T. Mazzucato.
University Corporation for Atmospheric Research, Windows to the Universe

Named after him
Lunar crater Schiaparelli
Martian crater Schiaparelli
Mercurian ridge Schiaparelli
Minor Planet #4062 Schiaparelli
Istituto Tecnico Commerciale Statale e P.A.C.L.E. Giovanni Schiaparelli
Schiaparelli Tower
La Grotta Schiaparelli (Schiaparelli Cave)
Osservatorio Astronomico G. V. Schiaparelli

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Giovanni Schiaparelli was born in Piedmont and studied hydraulic engineering and civil architecture at the University of Turin and then astronomy at the observatories at Berlin and Pulkovo. He worked at the Brera Observatory in Milan for forty years, all but the first two as director.

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Van McCoy - The Hustle And Best Of - The Hustle (Original Mix)

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Space rock slams into Mars, forming a crater that revealed chunks of ice | CNN

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Christmas came a little early for NASA’s InSight mission last December when the lander detected a massive quake on Mars. A space rock slammed into Mars on December 24, creating a crater and revealing ice buried near the Martian equator.

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I think his letters were nice, for potential last words, He made it a point to make sure that the crew did not blame themselves for the situation he was in. I think it is important that he keeped it mostly serious, but added just enough humor, to show that he was doing relatively fine for the situation he was in. And that they overall made the right choice

On the more personal side of things I think he did a great job saying things to the crew like telling them to follow their feelings, and goals.

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His letters were very heartfelt and upfront. He was trying to make them know and more so feel like that what happened was not the crews fault at all. As he said in his own words, "I would've left as well". I feel like his letter to Lewis was the most real. His feelings were very valid and real. I feel like his letter to Lewis was the most intimate because he felt and knew deep down that she took it the hardest since. Also going along with what Emma said, I feel like she made a good point in pointing out that he probably also wanted to write to them not only to give ease on their minds, but to also hear or let them hear him one last time incase this really will be the end.

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After Apollo 13's incident, will it happen again or be safer?

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After Apollo 13's incident, will it happen again or be safer?

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Apollo 13 Astronauts survived a major disaster. Will it be safer to try again? Could it happen again? According to this article NASA says yes. Not only will they try to go to the moon once again, it will be a lot more safer because of the more reliable systems now

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Apollo 13's Astronauts Survived Disaster 50 Years Ago. Could It Happen Again? (Published 2020)

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A trip to the moon later this decade should be safer, but it won't be safe. The damaged service module of the Apollo 13 mission, floating away after the astronauts jettisoned it before re-entry back to Earth. Credit... NASA Apollo 13 almost killed three NASA astronauts.

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Agatha Christie has written tons of great novels, but this book really stands out to me. I've always wanted to read death on the nile. I also feel like Watney would enjoy it as well while on the ship still waiting for an escape (or better entertainment haha).

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Death on the Nile is among Agatha Christie's best-loved and most famous works and is a sweeping mystery of love, jealously and betrayal. Agatha Christie drew inspiration for this novel from her travels in Egypt, picking up geographically and historical details throughout her time there.

When Agatha Christie adapted the story into a play, she dropped Hercule Poirot from the script as she felt that he drew too much attention on stage. The title was changed to Hidden Horizons and the play opened at Dundee Repertory Theatre. When the play moved to London's West End in 1946, the title was changed to Murder on the Nile. Later on in the same year the show opened on Broadway, and in 1950 a live television broadcast of the US play took place as part of the Kraft Television Theatre.

As ingenious an alibi as can well be imagined.

Sunday Times

Twentieth Century's Death on the Nile is due out in cinemas in February 2022, following the success of their 2017 adaptation of Murder on the Orient Express. Previous adaptations of Death on the Nile include the 1978 feature film which starred Peter Ustinov in his first role as Hercule Poirot. John Moffatt played Poirot in the first radio adaptation based on the book in 1997 which was broadcast as a five-part serial. In 2004, ITV's Agatha Christie's Poirot saw David Suchet take on the role in an adaptation which included famous faces Emily Blunt and James Fox. The novel has since been adapted into a hidden object PC game and a graphic novel.

Listen to an extract from the all new digital audio edition of Death on the Nile narrated by Kenneth Branagh, director and star of 20th Century Studios' upcoming Death on the Nile feature film. In this famous Agatha Christie mystery, Hercule Poirot's Egyptian adventure aboard a glamorous river steamer descends into a terrifying search for a murderer, with enough twists and turns to keep you unsettled and guessing until the final, shocking discovery. Kenneth Branagh reprises both his directorial role and that of the iconic detective in the upcoming film adaptation of Death on the Nile.

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Death on the Nile is one of Agatha Christie's popular detective stories featuring Hercule Poirot. Discover the background of the story here.

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On page 63,  NASA administrator Teddy Sanders pondered "What must it be like...he's stuck out there. He thinks he's totally alone and that we all gave up on him. What kind of effect does that have on a man's psychology?"

What is the impact of total isolation on a person?

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I think that he wrote what he wrote because he wanted to lift the spirits of the rest of the crew because he knows they all feel guilty. I think that he is also writing so he can have some last words with them in case something goes wrong and he dies without seeing them again.

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In 2021, a 34-meter disk was installed at one of the sites in Madrid. This upgraded it's communication abilities by nearly 32% so now the dish can receive and transmit signals of ALL frequencies, rather than communicating with missions of specific frequencies. Not every DSN site has these 34-meter dishes but NASA is working on upgrading the last of the smaller dishes in Madrid. The site in California only has 1 main 70-meter dish.

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This article talks about Frank Drake, the father of SETI. "Dr. Drake is interested in the possibility that the very numerous red dwarf stars that are much less bright than the Sun, might host habitual planets." The article then goes on to talk about how he also continued to design the Pioneer Plaque with Carl Sagan and how it was the first physical message that was sent into space.

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(Image credit: SETI Institute) Frank Drake, who conducted the first modern SETI experiment in 1960, continues his life-long interest in the detection of extraterrestrial sentient life. He participates in an ongoing search for optical signals of intelligent origin, carried out with colleagues from Lick Observatory and the University of California at Berkeley, using the 40-inch Nickel telescope at Lick.

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This video explains the Deep space network very well. It talks about how the antennas that pick up pictures and communication from the satellites in space. There are three and they are placed so that the waves sent from space can be picked up from anywhere on earth.

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What Is The Deep Space Network & How Does It Work?

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The acronym SETI stand for the (Search for Extra - Terrestrial intelligence). What makes it different than other organizations is that they are looking for alien intelligence, that does not mean that finding alien life is not part of their goal, however, they employ methods that are meant to find alien signals or technology, not so much biosignatures.

SETI uses things like radio telescopes, to pick up any civilization that has been able to launch radio waves into space. it also uses optical telescopes as well.

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SETI is a generic acronym that stands for the Search for Extraterrestrial Intelligence. Scientists doing SETI experiments are looking for proof - not merely of life elsewhere - but of intelligent beings in other star systems.

Scientists long ago realized that we can't find aliens by climbing into rockets and zipping off to other planetary systems. Such galactic galivanting is standard fare in movies and on television, a circumstance that has convinced many people that it's something humans will be doing real soon now. But the enormous distances to the stars (even the nearest is 7,000 times farther than Pluto) means that we simply aren't about to visit the aliens. Warp drive is a lovely idea, but no more than that.

And while some people think that the extraterrestrials, with their advanced technology, may be able to come here, this is not a popular idea among most scientists.

Consequently, most SETI these days eschews rockets, and relies on radio telescopes - massive antennas outfitted with highly sensitive and specialized receivers. The idea is simple: Forget the rockets and bring on the photons. Let signals beamed via radio (or light) do the traveling.

Radio is a great way to send information over the incredible distances between the stars; it easily passes through the dust and gas that suffuse space, and it does so at the speed of light (about 20,000 times faster than our best rockets.)

So, most SETI of the past 60 years has involved using large antennas to try and eavesdrop on any radio signals aliens might be transmitting.

There are also SETI experiments done with specially designed optical systems that search for flashing laser light beamed into space by other societies to convey information, to propel their rockets, or to just ping other star systems to see if anyone is home.

Note that SETI experiments do not broadcast. They just try to pick up signals that might already be threading the galaxy.

While technology pioneers such as Nikola Tesla and Guglielmo Marconi believed they could use radio to pick up signals from Martians (and both thought they had actually heard some Red Planet residents!), modern SETI dates from 1959. In that year, two physicists, Phillip Morrison and Giuseppe Cocconi, cooked up a very simple thought experiment. They imagined taking the world's most powerful radar transmitter, and aiming it at a large, receiving antenna. Of course, if you did this little experiment in your back yard, the big antenna would have no difficulty picking up the signal from the radar transmitter. But then, in their minds, the two physicists slowly separated the transmitter and receiver. They wanted to know how far apart they could be and still reliably establish a radio link.

To their surprise, it turned out that this setup would work even when the transmitter and the receiver were separated by light-years of distance!

In other words, even with the radio technology we had in the 1950s, it was theoretically possible to use radio for signaling across distances comparable to those between the stars. This remarkable calculation prompted the two scientists to write up a paper suggesting that maybe intelligent aliens were using radio to communicate, and that we should look for such signals.

The first one to actually do any looking was astronomer Frank Drake. In 1960 he used an 85-foot diameter antenna in Green Bank, West Virginia to hunt for signals that might be coming from two very nearby star systems. In the two weeks of his experiment, Drake didn't hear any alien transmissions. But his modest effort, known as Project Ozma, was the beginning of modern SETI.

Why hasn't SETI picked up any alien signals?

Some people think that, after six decades of searching, the fact that SETI researchers have yet to pick up a signal from space might mean something. Perhaps the aliens don't want to broadcast in our direction (maybe we're not worthy!) Others think that the apparent silence means that there are no intelligent beings out there, and humans are the smartest things in the galaxy, a circumstance that many readers might find comforting or possibly self-evident.

But there's a more reasonable explanation for the fact that SETI receivers have so far heard nothing that's clearly extraterrestrial. Namely, the experiments have simply not examined enough of the sky. Or perhaps the antennas don't have enough sensitivity, or maybe they've not been tuned to the correct frequency. So, if you buy into any of these explanations - which maintain that we haven't found any aliens simply because we haven't tried hard enough - then our future strategy is obvious. We simply have to be patient and continue to press the search.

Said another way, we continue to assume that the trillion or so planets in the Milky Way house some transmitting societies, but our experiments have to continue and continue to improve in order to succeed in picking up a signal.

There are countless other explanations for the "great silence." Some of these are sociological (the aliens don't find us interesting or worthy) while others are paranoid (broadcasting into space is dangerous, so the aliens don't do it.) However, the real reason that SETI has yet to find any convincing signals might only become clear once we've detected something.

Following Frank Drake's pioneering experiment (see above), John Billingham, a British physician working at the NASA Ames Research Center in Mountain View, California was inspired to start a small NASA project to do SETI in a systematic way. Over the course of a dozen years, this focused effort developed expertise, hardware and software. The NASA project was just beginning its survey of the sky when it was canceled in 1993 by a vote in the U.S. Senate.

Since that time, all SETI in the United States has been funded by private donations.

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SETI SETI is a generic acronym that stands for the Search for Extraterrestrial Intelligence. Scientists doing SETI experiments are looking for proof - not merely of life elsewhere - but of intelligent beings in other star systems.

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This was the first Agatha Christie novel mentioned by Mark, written during WW1. Her knowledge of medicines as a wartime nurse made the main murder method a poison mystery. This was just the first book of the series.

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The Mysterious Affair at Styles by Agatha Christie

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Agatha Christie's first novel, The Mysterious Affair at Styles, was the result of a dare from her sister Madge who challenged her to write a story. The story begins when Hastings is sent back to England from the First World War due to injury and

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Reflect on NASA's decision not to inform the Hermes crew that Mark Watney survived. Are you team Mitch Henderson or Team Venkat Kapoor? Why?

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This week we are celebrating American ingenuity with the anniversary of Pathfinder, which landed on Mars on Independence Day in 1997.

What was NASA's Pathfinder mission?

Pathfinder was the second mission in NASA's Discovery Program, which centered around fast track, low-cost missions with a focus on scientific objectives. It was the first of these missions to be completed.

NASA's Mars Pathfinder was designed to demonstrate a cost-effective way of delivering science instruments and a free-ranging rover to the surface of Mars.

Pathfinder launched on Dec. 4, 1996 and touched down on Mars on the Fourth of July in 1997. This marked the return of NASA to the red planet, making Pathfinder the first spacecraft to touch down on the Martian surface in over 20 years.

The mission was a monumental success. On Sept. 27, 1997, Pathfinder sent its final transmission, operating far longer than was expected.

How did the lander and rover get their names?

A year-long competition was held to name NASA's Mars Pathfinder rover. Students submitted stories of their favorite heroines in a bid to name the rover. The winning entry was about Sojourner Truth, an American civil rights activist during the Civil War era. Thus, the rover was named Sojourner, meaning "traveler," which suited the Martian vehicle perfectly.

Following touchdown on the red planet, the lander was named the Carl Sagan Memorial Station, after the famed American astrophysicist and science educator.

What did the Pathfinder mission discover about Mars?

Scientific instruments used during the mission included: an Alpha Proton X-Ray Spectrometer to determine the elemental composition of rock and soil samples; three cameras for imaging; and an Atmospheric Structure Instrument/Meteorology Package, used to study the Martian atmosphere.

The Pathfinder mission led to multiple scientific discoveries about the red planet, including the following:

Panoramic images of Pathfinder's landing site at Ares Vallis and the presence of rounded pebbles and cobbles suggested that Mars had a warmer, wetter past.

The presence of grooved rocks at and around the landing site indicated the presence of sand on Mars.

The radius of the planet's magnetic core was found to be more than 800 miles but fewer than approximately 1,250 miles.

Dust devils, or whirlwinds, were photographed and studied.

The airborne dust on Mars was discovered to be magnetic. It is hypothesized that the magnetic mineral is maghemite, a magnetic form of iron oxide.

NASA found that the Martian atmosphere gets its yellowish-brown color due to the mixing of fine dust in the lower atmosphere.

It was discovered that the red planet's atmosphere is heated by the Martian surface.

Early morning ice clouds were imaged in the lower atmosphere, which evaporated as it heats up.

Pathfinder returned 2.3 billion bits of data, which included 550 images from Sojourner and over 16,500 images from the lander. Over 15 chemical analyses of rock and soil samples were also returned, along with data on Martian wind and weather. The mission concluded with a final transmission on Sept. 27, 1997, with both the lander and rover outliving their expected design lives.

More fun facts about the Pathfinder mission:

Sojourner's top speed was two feet per minute.

Sojourner was the first wheeled rover on any planet.

8.5 million temperature, pressure, and wind measurements were returned from the mission.

This mission marked the first time the air bag technique, used to cushion the impact during landing, had been utilized.

Pathfinder played a role in the blockbuster hit "The Martian," when astronaut Mark Watney (played by Matt Damon) digs up the old spacecraft to establish communications between his location on Mars and NASA personnel back on Earth. Watch the short clip below for an explanation on the Pathfinder replica from "The Martian" director Ridley Scott!

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This week we are celebrating American ingenuity with the anniversary of Pathfinder, which landed on Mars on Independence Day in 1997. Pathfinder was the second mission in NASA's Discovery Program, which centered around fast track, low-cost missions with a focus on scientific objectives. It was the first of these missions to be completed.

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How It Works

Radioisotope Thermoelectric Generators (RTGs) are lightweight, compact spacecraft power systems that are extraordinarily reliable.

RTGs provide electrical power using heat from the natural radioactive decay of plutonium-238, in the form of plutonium dioxide. The large difference in temperature between this hot fuel and the cold environment of space is applied across special solid-state metallic junctions called thermocouples, which generates an electrical current using no moving parts.

How We Used It

Electrical power for Cassini's science instruments and onboard systems was generated by three RTGs, known as General Purpose Heat Source (GPHS) RTGs.

The spacecraft also carried 82 strategically placed radioisotope heater units (RHUs), which provided focused warmth in the form of one watt of thermal power each using a pencil eraser-sized pellet of plutonium dioxide. The Huygens probe used 35 similar RHUs to keep it warm on its descent to the frigid surface of the frigid Titan.

The RPS used to power NASA spacecraft, including Cassini, are supplied by the U.S. Department of Energy (DOE). NASA and DOE continue to collaborate on maintaining the current Multi-Mission Radioisotope Thermoelectric Generator (now in use on Mars by the Curiosity rover), and related RPS technology.

RTGs are used on NASA missions where other options such as solar power are impractical or incapable of providing the power that a mission may need to accomplish its scientific or operational goals. Sometimes referred to as "nuclear batteries," RTGs are not fission reactors, nor is the plutonium the type that is used for nuclear weapons. More than two dozen U.S. space missions have used RTGs since the first one was launched in 1961.

For more details on RTGs, visit NASA's Radioisotope Power System homepage.

There are no gas stations or power outlets in space. That's why Cassini -- and some other NASA spacecraft that explore the solar system--use something called "radioisotope power."

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Radioisotope Thermoelectric Generators (RTGs) | Cassini - NASA Solar System Exploration

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Radioisotope Thermoelectric Generators (RTGs) are lightweight, compact spacecraft power systems that are extraordinarily reliable. RTGs provide electrical power using heat from the natural radioactive decay of plutonium-238, in the form of plutonium dioxide. The large difference in temperature between this hot fuel and the cold environment of space is applied across special solid-state metallic junctions called thermocouples, which generates an electrical current using no moving parts.

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The Fonz in Happy days. This is how Watney posed when they took a picture of him in ch. 11

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Radioisotope Thermoelectric Generator (RTG) 

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Radioisotope Thermoelectric Generator (RTG) 

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https://www.youtube.com/watch?v=U4teGsZiBGU

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Humans are social creatures, and it is hard for the majority of us to be distant from others. One great example is COVID -19 Quarantine. Many people devloped issues from it and even if it didn't it still caused everyone to be less happy.

Even before Covid some people started to speak out against solitary confinement, which is isolation in prisons if a prisoner does something wrong to the point, he or she is considered a danger to staff or other prisoners.

I don't take sides on stuff like this but it is interesting that social interaction is so important to our wellbeing that it could be considered inhuman to take it away from someone, It may also bring into question is it ethical to send people to Mars if so, how you deal with the isolation since comms will be slowed and in case of emergency may not exist.

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Also known as maximum security, segregation or lockdown, solitary confinement is, literally speaking, a prison within a prison, where criminals and convicts who violate the institution's rules and regulations are put. They are placed in a cell and are not allowed any communication with other prisoners. Most of the time, people under solitary confinement are left in their cells for 23 hours a day, an act considered by some people as a necessary disciplinary action, but inhumane for others.

Considering that prisoners are also human beings who are social creatures and need interaction in order to stay mentally healthy, is solitary confinement reasonable enough to implement in a prison system? To get a good insight about this subject, it is best to look at its pros and cons.

List of Pros of Solitary Confinement

1. It provides prisoners with some form of protection from the general public.
High-risk offenders and other dangerous prisoners, such as murderers, child molesters and ex-gang members, can be kept segregated with solitary confinement. As it uses much higher security protocols, it would be more difficult for such prisoners to harm others.

2. It provides an added level of protection for the public.
As imprisonment can be justified when it offers protection to the public from serious threats, the same reason goes for locking up those who are likely to re-offend and even for detaining someone indefinitely.

3. It offers prison safety.
One of the main reasons why solitary confinement is implemented is when a prisoner is being regarded as a threat to staff and other inmates. Those who support it argue that it is absolutely needed in order to ensure the majority's safety.

4. It still allows prisoners to serve their sentences.
Some people might say that death inside prison systems is justice serving itself, but vigilantism is not supported by the laws of the US and other developed nations. So, solitary confinement would allow for sentences to be served more accurately in a morally appropriate fashion.

5. It provides prison guards another means to discipline prisoners.
Without some sort of punishment for negative behavior, it would be nearly impossible for prison guards to maintain order within the prison walls. Most likely, an individual does not like the idea of being locked up on his own without allowing him to experience any human contact for weeks on end, thus a delicate balancing act would be enforced.

6. It aids in the reformation of prisoner characters.
Another justifiable aim of the criminal justice system is rehabilitation or reformation of character. According to Dr. Sharon Shalev, this was a historic rationale for solitary confinement. She said, "Solitary confinement was first widely and systematically used on both sides of the Atlantic in the 'separate' and 'silent' penitentiaries of the 19th century, with the aim of reforming convicts. It was believed that once left alone with their conscience and the Bible, prisoners would engage in inner reflection, see the error of their ways and be reformed into law abiding citizens."

7. It can somehow satisfy the interests of the victims and members of the public to see wrong-doers punished.
Solitary confinement can provide some kind of justification to increase a punishment in some situations, other things being equal, but the extent victims and the public are being satisfied has been put in question. The interest of society members to see offenders being punished might provide a rationale for solitary confinement, at least when an existing penalty is clearly regarded as "too weak". However, the sufficiency of this interest is still doubtful, considering the serious harms solitary confinement would bring, so it should be coupled with other benefits.

List of Cons of Solitary Confinement

1. It creates the loss of freedom.
If someone is being isolated in cell, he would be stripped of the feeling of having control over his surroundings, which can result in increased anxiety, paranoia and claustrophobia. In fact, most prisoners who were put under such a punishment have tried to gain control over their surroundings by resorting to a self-destructive behavior.

2. It may not meet all of the prisoner's needs.
Most policies of solitary confinement would require 22-23 hours of isolation in a small cell every day, where 1-2 hours of recreation are given to prisoners, while still being locked into another cage outside with nothing to do except for standing around and waiting for the time outside to pass by.

3. It violates basic human rights.
Solitary confinement can actually fit the definition of torture, as stated in some international human rights treaties. This means that it constitutes a violation to human rights. As an example, the UN Convention Against Torture clearly defines torture as an act through which severe pain and suffering, whether physical or mental, is intentionally inflicted on a person for punishment, intimidation, information or for other reasons, such as discrimination.

4. It offers little to no privacy to prisoners.
Under solitary confinement, guards would monitor the movements of inmates by using video cameras, and communication between control booth officers and prisoners is mostly done through the vents. All processes are done electronically.

5. It might cause prisoners to have personality and mental health disorders.
Those who are being isolated would be vulnerable or at risk of having mental disorders, such as schizophrenia. They might experience delusions and hallucinations, as well as become very paranoid or may display symptoms of mental distress, making them lose their grip on reality.

6. It provides no real purpose of rehabilitation.
The primary purpose of incarceration systems is offering prisoners the chance to rehabilitate themselves and transform into something better than they thought they could be. However, this purpose is often forgotten with solitary confinement, where the goal is often to just let time pass by as quickly as possible. Rehabilitation requires human interaction, and isolation is best for administrative segregation or short-term protective custody. Anything beyond that would be punitive and cruel.

Conclusion

Some people see solitary confinement as one of the most difficult ways to do time, while others seek it out to feel safe while in prison. So, is it an ethical incarceration practice? By weighing down its pros and cons, each of us will have sufficient knowledge to decide which side of the debate he or she supports.

Author Bio
Natalie Regoli is a child of God, devoted wife, and mother of two boys. She has a Master's Degree in Law from The University of Texas. Natalie has been published in several national journals and has been practicing law for 18 years.

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13 Most Valid Pros and Cons of Solitary Confinement

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Also known as maximum security, segregation or lockdown, solitary confinement is, literally speaking, a prison within a prison, where criminals and convicts who violate the institution's rules and regulations are put. They are placed in a cell and are not allowed any communication with other prisoners.

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The phycological issues that come up in space flight has been a issue for NASA ever since Gemini mission's and they have actually  created a lab to study what long term isolation does to people it is actually placed in Hawaii. It is called HI-SEAS and it is a 8- month program where NASA sends out groups of people to be Isolated. During the eight months they are required to grow food as well as other tasks that may be required on a trip to Mars.

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HI-SEAS Team Completes 8-Month Isolation Mission

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A team of six volunteer scientists completed one of the most extensive studies of the demands of life on a distant world by closing themselves off to the rest of the world for eight months in an effort known as HI-SEAS.

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These are pictures from the Mars Reconnaissance orbiter and it has been studying the atmosphere and geography since 2006.

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Mars Reconnaissance Orbiter - missions, videos, images and information

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Agatha Christie is one of the best-selling novelists ever~ outsold only by the Bible and Shakespeare according to www.agathachristie.com. Her best know detective protagonists are Miss Marple and Hercule Poirot.

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Adam Savage Interviews 'The Martian' Author Andy Weir - The Talking Room

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Could you survive on vitamin pills and water alone?

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The question is why would you ever want to do such a thing!

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Watney says at the beginning of ch.7 that ares 4 could be anywhere from 4-20 light minutes away. For reference, 1 light minute is about 11.177 million miles away. So they are a longgg ways away

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There are many alternatives to solar power when it comes to mars, the book mentions one Which are RTG, however, there are many other granted non really help Mark Watney while he is moving on the rover.

One commonly known one is nuclear power which Mark Watney, said helped power the Hermes.  Unlike RTG this is an actual nuclear reactor which although heavy and hard to move it would prove to be a lot more efficient than any other alternative know to current science.  It would use Uranium or Plutonium to create power much the same way reactors on earth do right now.  Chance are they would be bigger then the reactors that power todays aircraft carriers and subs.

A lesser known ones include, wind energy, this is the same as wind on earth just less powerful mars does not have as strong of wind because of it lower atmospheric pressure, interesting side note this is also why it was more difficult to build the ingenuity helicopter then a helicopter on Earth . The surface area of a blade on a wind turbine would have to be bigger in order to create more energy.

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Mars Technologies Spawn Durable Wind Turbines

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The Ames group started looking at maximizing energy use efficiency and alternative methods to make power on a planet that is millions of miles away from Earth. They turned to a hybrid concept combining two renewable sources: wind and solar power technologies.

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As explained in the book solar panels loose effectiveness the further from a light source it gets there are a couple ways around this, which I will post under technology, however, the reason why Solar panels loose effectiveness is the "Inverse Square law" discovered by Robert Hooke. Which more broadly is law that states that a physical quantity is inversely proportional to the square root of the distance from a source. this law holds true with many things, such as heat and light.

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Educator Guide: Calculating Solar Power in Space | NASA/JPL Edu

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Students explore practical applications of exponents and division to investigate what it takes for NASA spacecraft to travel deep into the solar system using only solar power.

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The RTG basically functions as described in chapter 7; NASA either uses the RTGs as a heat source (like Mark) or a nuclear battery when solar power can't be taken advantage of.

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How It Works

Radioisotope Thermoelectric Generators (RTGs) are lightweight, compact spacecraft power systems that are extraordinarily reliable.

RTGs provide electrical power using heat from the natural radioactive decay of plutonium-238, in the form of plutonium dioxide. The large difference in temperature between this hot fuel and the cold environment of space is applied across special solid-state metallic junctions called thermocouples, which generates an electrical current using no moving parts.

How We Used It

Electrical power for Cassini's science instruments and onboard systems was generated by three RTGs, known as General Purpose Heat Source (GPHS) RTGs.

The spacecraft also carried 82 strategically placed radioisotope heater units (RHUs), which provided focused warmth in the form of one watt of thermal power each using a pencil eraser-sized pellet of plutonium dioxide. The Huygens probe used 35 similar RHUs to keep it warm on its descent to the frigid surface of the frigid Titan.

The RPS used to power NASA spacecraft, including Cassini, are supplied by the U.S. Department of Energy (DOE). NASA and DOE continue to collaborate on maintaining the current Multi-Mission Radioisotope Thermoelectric Generator (now in use on Mars by the Curiosity rover), and related RPS technology.

RTGs are used on NASA missions where other options such as solar power are impractical or incapable of providing the power that a mission may need to accomplish its scientific or operational goals. Sometimes referred to as "nuclear batteries," RTGs are not fission reactors, nor is the plutonium the type that is used for nuclear weapons. More than two dozen U.S. space missions have used RTGs since the first one was launched in 1961.

For more details on RTGs, visit NASA's Radioisotope Power System homepage.

There are no gas stations or power outlets in space. That's why Cassini -- and some other NASA spacecraft that explore the solar system--use something called "radioisotope power."

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Radioisotope Thermoelectric Generators (RTGs) | Cassini - NASA Solar System Exploration

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Radioisotope Thermoelectric Generators (RTGs) are lightweight, compact spacecraft power systems that are extraordinarily reliable. RTGs provide electrical power using heat from the natural radioactive decay of plutonium-238, in the form of plutonium dioxide. The large difference in temperature between this hot fuel and the cold environment of space is applied across special solid-state metallic junctions called thermocouples, which generates an electrical current using no moving parts.

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The eye of a potato is how it sprouts and grows. When he was planting the parts of potatoes, he made sure to have at least 2 eyes per part he planted. This would double the chances that the potato would sprout and survive.

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Mark Watney is intelligent but needs to be Cautious

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Mark Watney is intelligent but needs to be Cautious

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Mark Watney is very intelligent but he must be cautious and more concerned about his every move. He needs to start throughly thinking through the consequences of every action he does in order to survive. When trying to burn the hydrogen, just a little too much oxygen was still in the Hab causing an explosion.  It's mistakes like these that might cause him his life.

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It is just crazy how smart he is trying to figure out how to grow things, have oxygen, fix the air, get water and deal with all of these things that have a reaction on each other while it keeps going wrong. he also somehow manages to stay calm and think through to get a solution.

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The live audience is just so corny to me, I can see why Mark hated it.

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Clip: THREE'S COMPANY - 12/5/1978 - ''The Party's Over'' - Jack and Roper wake up in the same bed

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Consuming around 5 potatoes a day would give you the essential amino acids for your cells to function properly, though that would lead to a major vitamin and calcium deficiency. Consuming large amounts of potatoes will also lead to a buildup of starch in the body that will disrupt the body's insulin production.

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For all of 2016, Andrew Taylor ate only potatoes. There were a few caveats to his potato diet: He ate both white potatoes and sweet ones, and sometimes mixed in soymilk, tomato sauce, salt and herbs. He also took B12 supplements. But, overall, he ate potatoes for breakfast, lunch, and dinner. He took four blood tests over the year which he claims all came back normal. He even lost weight and felt more energized.

"If you have to choose one food, if you're one of the people that's getting sent to Mars, choose potatoes," says Taylor. "I'm not trying to be evangelical about potatoes, but it was a really good experience for me."

First and foremost, it's not a good idea to only eat one kind of food. To survive, we need 20 amino acids-of which nine are essential, meaning we can't make them ourselves and must get them from food-as well as a plethora of minerals and vitamins. (And, obviously, we need water in addition to food to keep our cells hydrated so they don't wither and stop functioning.) Throughout history we've often combined foods, like rice and beans, yogurt and nuts, and even macaroni and cheese to a certain extent, in an attempt, or by accident, to intake the proper balance of nutrients that you usually can't attain from eating a single food item. But in times of famine, fasting, or strange double-dog-dares, there are a couple of foods a human could survive on...at least for awhile.

The potato diet

The potato is one good example. Andrew Taylor isn't the only person in history who has relied almost exclusively on potatoes for sustenance. In the beginning of the 1800s, about a third of the Irish population got most of their calories from spuds. The average American ate about 113 pounds of these starchy tubers in 2015. "For the money and your blood pressure, you can't beat a traditional baked spud," says Joan Salge Blake, a clinical nutrition professor at Boston University.

Technically, the traditional white potato contains all the essential amino acids you need to build proteins, repair cells, and fight diseases. And eating just five of them a day would get you there. However, if you sustained on white potatoes alone, you would eventually run into vitamin and mineral deficiencies. That's where sweet potatoes come in. Including these orangey ones in the mix-technically, they belong to a different taxonomic family than white potatoes-increases the likelihood that the potato consumer will get their recommended daily dose of Vitamin A, the organic compound in carrots that your mom told you could make you see in the dark, and Vitamin E. No one on a diet of sweet potatoes and white potatoes would get scurvy, a famously horrible disease that happens due to a lack of Vitamin C and causes the victim's teeth to fall out.

Even with this combo, you'll still need to eat a lot of spuds before you intake the right levels of everything. Consuming five potatoes would give you all the essential amino acids you need to build proteins, repair cells, and fight diseases. But unless you ate 34 sweet potatoes a day, or 84 white potatoes, you would eventually run into a calcium deficiency. You would also need 25 white potatoes a day to get the recommended amount of protein. Soybeans have more protein and calcium-but they don't have any Vitamin E or beta-carotene.

Of course, there are a lot of health disadvantages to potatoes, especially when you eat them en masse. White potatoes are high in a kind of carbohydrate that causes your blood sugar to spike and then dip, which puts a strain on the insulin system. People who ate a lot of these tubers were more likely to get diabetes and become obese, according to multiple studies.

Andrew Taylor actually lost weight-probably from eating less overall and giving up sugar -which wasn't his ultimate goal. He quit eating most food to train himself to get comfort and joy from other areas of his life. But now even though his spud experiment is over, he still gets pretty excited about potatoes. "It was just an experiment and turned out to be exactly like I wanted," he says.

Foods you can survive on

No nutritionist would get on board with an all-potato diet. Nor would they recommend an all coconut, kale, seaweed, or yogurt one either. There's a reason that the U.S. dietary guidelines recommends eating a variety of vegetables, grains, proteins, fruits, and oils. Eat any of these just by themselves and you would soon run into the same nutritional deficiencies that you would with a potato. Variety is important, and in this case, it's vital. So don't just eat a baked potato, load it with other healthy stuff, too.

** This article originally stated that we need 20 essential amino acids to survive, when, in fact, we need 20 amino acids in total, of which nine are essential. The article has been updated to reflect that. We regret the error.

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Is there a single food that you can survive on forever?

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For all of 2016, Andrew Taylor ate only potatoes. There were a few caveats to his potato diet: He ate both white potatoes and sweet ones, and sometimes mixed in soymilk, tomato sauce, salt and herbs. He also took B12 supplements. But, overall, he ate potatoes for breakfast, lunch, and dinner.

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The Ion drive mention in chapter 1 is something that is actually being worked on by many space agencies

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Ion thrusters, the propulsion of choice for science fiction writers have become the propulsion of choice for scientists and engineers at NASA. The ion propulsion system's efficient use of fuel and electrical power enable modern spacecraft to travel farther, faster and cheaper than any other propulsion technology currently available. Chemical rockets have demonstrated fuel efficiencies up to 35 percent, but ion thrusters have demonstrated fuel efficiencies over 90 percent. Currently, ion thrusters are used to keep communication satellites in the proper position relative to Earth and for the main propulsion on deep space probes. Several thrusters can be used on a spacecraft, but they are often used just one at a time. Spacecraft powered by these thrusters can reach speeds up to 90,000 meters per second (over 200,000 mph). In comparison, the Space Shuttles can reach speeds around 18,000 mph.

The trade-off for the high top speeds of ion thrusters is low thrust (or low acceleration). Current ion thrusters can provide only 0.5 newtons (or 0.1 pounds) of thrust, which is equivalent to the force you would feel by holding 10 U.S. quarters in your hand. These thrusters must be used in a vacuum to operate at the available power levels, and they cannot be used to put spacecraft in space because large amounts of thrust are needed to escape Earth's gravity and atmosphere.

Image right: Artist's concept of Deep Space 1 probe with its ion thruster operating at full power.
Credit: NASA

To compensate for low thrust, an ion thruster must be operated for a long time for the spacecraft to reach its top speed. Acceleration continues throughout the flight, however, so tiny, constant amounts of thrust over a long time add up to much shorter travel times and much less fuel used if the destination is far away. Deep Space 1 used less than 159 pounds of fuel in over 16,000 hours of thrusting. Since much less fuel must be carried into space, smaller, lower-cost launch vehicles can be used.

Propulsion

Sir Isaac Newton's third Law states that every action has an equal and opposite reaction. This is like air escaping from the end of a balloon and propelling it forward. Conventional chemical rockets burn a fuel with an oxidizer to make a gas propellant. Large amounts of the gas push out at relatively low speeds to propel the spacecraft.

Image left: Xenon ion discharge from the NSTAR ion thruster of Deep Space 1. Credit: NASA

Modern ion thrusters use inert gases for propellant, so there is no risk of the explosions associated with chemical propulsion. The majority of thrusters use xenon, which is chemically inert, colorless, odorless, and tasteless. Other inert gases, such as krypton and argon, also can be used. Only relatively small amounts of ions are ejected, but they are traveling at very high speeds. For the Deep Space 1 probe, ions were shot out at 146,000 kilometers per hour (more than 88,000 mph).

Making Ions and Plasma

Ion thrusters eject ions instead of combustion gases to create thrust: the force applied to the spacecraft that makes it move forward. An ion is simply an atom or molecule that has an electrical charge because it has lost (positive ion) or gained (negative ion) an electron. With ion propulsion, the ions have lost electrons, so they are positively charged. A gas is considered to be ionized when some or all the atoms or molecules contained in it are converted into ions.

Plasma is an electrically neutral gas in which all positive and negative charges--from neutral atoms, negatively charged electrons and positively charged ions--add up to zero. Plasma exists everywhere in nature (for example, lightning and fluorescent light bulbs), and it is designated as the fourth state of matter (the others are solid, liquid and gas). It has some of the properties of a gas but is affected by electric and magnetic fields and is a good conductor of electricity. Plasma is the building block for all types of electric propulsion, where electric and/or magnetic fields are used to accelerate the electrically charged ions and electrons to provide thrust. In ion thrusters, plasma is made up of positive ions and an equal amount of electrons.

NASA's conventional method of producing ions is called electron bombardment. The propellant is injected into the ionization chamber from the downstream end of the thruster and flows toward the upstream end. This injection method is preferred because it increases the time that the propellant remains in the chamber.

In such ion thrusters, electrons are generated by a hollow cathode, called the discharge cathode, located at the center of the thruster on the upstream end. The electrons flow out of the discharge cathode and are attracted (like hot socks pulled out of a dryer on a cold day) to the discharge chamber walls, which are charged highly positive by the thruster's power supply.

Image left: Ion thruster operation: Step 1--Electrons (shown as small, pale green spheres) are emitted by the discharge hollow cathode, traverse the discharge chamber, and are collected by the anode walls. Step 2--Propellant (shown in green) is injected from the plenum and travels toward the discharge cathode. Step 3--Electrons impact the propellant atoms to create ions (shown in blue). Step 4--Ions are pulled out of the discharge chamber by the ion optics. Step 5--Electrons are injected into the beam for neutralization. Credit: NASA

When a high-energy electron (negative charge) from the discharge cathode hits, or bombards, a propellant atom (neutral charge), a second electron is released, yielding two negative electrons and one positively charged ion. High-strength magnets are placed along the discharge chamber walls so that as electrons approach the walls, they are redirected into the discharge chamber by the magnetic fields. Maximizing the length of time that electrons and propellant atoms remain in the discharge chamber, increases the chances that the atoms will be ionized.

NASA also is researching electron cyclotron resonance to create ions. This method uses high-frequency radiation (usually microwaves) coupled with a high magnetic field to add energy to the electrons in the propellant atoms. This causes the electrons to break free of the propellant atoms and create plasma. Ions can then be extracted from this plasma.

In a gridded ion thruster, ions are accelerated by electrostatic forces. The electric fields used for this acceleration are generated by two electrodes, called ion optics or grids, at the downstream end of the thruster. The greater the voltage difference between the two grids, the faster the positive ions move toward the negative charge. Each grid has thousands of coaxial apertures (or tiny holes). The two grids are spaced close together (but not touching), and the apertures are exactly aligned with each other. Each set of apertures (opposite holes) acts like a lens to electrically focus ions through the optics.

NASA's ion thrusters use a two-electrode system, where the upstream electrode (called the screen grid) is charged highly positive, and the downstream electrode (called the accelerator grid) is charged highly negative. Since the ions are generated in a region that is highly positive and the accelerator grid's potential is negative, the ions are attracted toward the accelerator grid and are focused out of the discharge chamber through the apertures, creating thousands of ion jets. The stream of all the ion jets together is called the ion beam. The thrust is the force that exists between the upstream ions and the accelerator grid. The exhaust velocity of the ions in the beam is based on the voltage applied to the optics. Whereas a chemical rocket's top speed is limited by the heat-producing capability of the rocket nozzle, the ion thruster's top speed is limited by the voltage that is applied to the ion optics, which is theoretically unlimited.

Because the ion thruster ejects a large amount of positive ions, an equal amount of negative charge must be ejected to keep the total charge of the exhaust beam neutral. Otherwise, the spacecraft itself would attract the ions. A second hollow cathode called the neutralizer is located on the downstream perimeter of the thruster and pushes out the needed electrons.

Electric Propulsion System

The ion propulsion system consists of five main parts: the power source, the power processing unit, the propellant management system, the control computer, and the ion thruster. The power source can be any source of electrical power, but solar or nuclear are usually used. A solar electric propulsion system (like that on Deep Space 1) uses sunlight and solar cells to generate power. A nuclear electric propulsion system (like that planned for the Jupiter Icy Moons Orbiter) uses a nuclear heat source coupled to an electric generator.

Image right: HiPEP ion thruster being tested at 20 kilowatts in Glenn's Vacuum Facility 6. For comparison, a household microwave operates at about 1 kilowatt. Credit: NASA

The power processing unit converts the electrical power generated by the power source into the power required for each component of the ion thruster. It generates the voltages required by the ion optics and discharge chamber and the high currents required for the hollow cathodes. The propellant management system controls the propellant flow from the propellant tank to the thruster and hollow cathodes. It has been developed to the point that it no longer requires moving parts. The control computer controls and monitors system performance. The ion thruster then processes the propellant and power to propel the spacecraft.

The first ion thrusters did not last very long, but the ion thruster on Deep Space 1 exceeded expectations and was used more than 16,000 hours during a period of over 2 years. The ion thrusters being developed now are being designed to operate for 7 to 10 years.

Find out more about ion propulsion:
> Glenn Ion Propulsion Research and Development
> Deep Space 1 Technologies From Glenn

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NASA - National Aeronautics and Space Administration

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Ion thrusters, the propulsion of choice for science fiction writers have become the propulsion of choice for scientists and engineers at NASA. The ion propulsion system's efficient use of fuel and electrical power enable modern spacecraft to travel farther, faster and cheaper than any other propulsion technology currently available.

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He is quirky, smart, sarcastic, and has an ego, but in a good way.

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Mark Watney is clever, hard headed, strong, blunt, funny, sarcastic. He is very smart and determined to do what it takes to survive and get home, but if it fails he doesn't seem scared.

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Mark is a bottom of the line botanist, that is very experienced in his field. He’s extremely dedicated and knowledgeable on his subject of study and finds a way to be snarky in almost every situation.

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He cares about the people he was on the mission with, and does not want them to feel guilty.

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Nine Real NASA Technologies in ‘The Martian’

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Andy Weir’s “The Martian” tells the story of Mark Watney, a NASA astronaut stranded on Mars. He must improvise and innovate to survive. NASA is already working on some of the technologies he uses to try to stay alive.

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He attended the University of Chicago.

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We call Chicago home

Chicago is not only in our name, it's woven into the fabric of this institution. Located in the Hyde Park neighborhood, we benefit from the diversity, arts, and vibrant culture of our South Side community.

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One of the world's leading research universities, the University of Chicago inspires scholars to pursue field-defining research, while providing a transformative education for students.

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October 29, 2018
Episode 1: Getting to Mars is Hard

The InSight mission is heading to Mars, but many spacecraft have died trying to get there. The current record for Mars missions is 18 successes, and 25 failures. InSight hopes to improve the odds.

Transcript:(music)
[0:04] Narrator: Come with me on a mission to outer space. Our destination is the planet Mars. We have to travel over 300 million miles. That may seem like a long trip, but we'll be speeding through space at 13,000 miles an hour.
(intro music montage)
[0:49] Narrator: Welcome to "On a Mission," a podcast of NASA's Jet Propulsion Laboratory in Pasadena, California. I'm Leslie Mullen. I'm a science journalist, and I arrived at the Jet Propulsion Laboratory - also known as JPL - two years ago.

[1:03] The Lab is a jumble of buildings at the foot of the San Gabriel Mountains, and just down the road from Hollywood. But at JPL, they're focused on stars of a different sort. JPL is like a little town, but a town full of scientists and engineers who study the mysteries of the universe and build robots to send to outer space. In my short time here, I've discovered there are a million stories to tell.

[1:28] The concept of this podcast is to take a close look at a single space mission, and examine it from different angles. To share the science, yes, but also the struggle and satisfaction in getting a mission off the ground. For this first season, the focus will be on the InSight mission to Mars.
(rocket launch, with music)
[2:13] Narrator: A rocket carrying the InSight mission launched from Vandenberg Air Force Base in California earlier this year, on May 5. It is now on its way to Mars, due to arrive at the end of November. After it lands, the robotic suite of instruments will peek below the planet's surface, investigating the different layers that make up Mars.

[2:34] You may already know that Mars is the fourth planet from the Sun. Earth is the third planet from the Sun, so Mars is a little farther out than we are. On a clear night, when you can see the stars, you may have noticed one that looked a little reddish. Sunlight bouncing off the Martian red rocks makes it look like just another star, but Mars is world: a harsh, desert, alien world.
(music)
[3:01] Narrator: Over the years, NASA has sent many spacecraft to Mars. But it's still a mysterious place, in many ways, one that we've only just begun to explore.

[3:10] But Mars does not welcome visitors with open arms. Many spacecraft have died trying to get there. So far, there have been 43 robotic missions sent to Mars - many from the US, but Europe and Russia and even India and China have tried to go there. The current record for Mars missions is 18 successes, and 25 failures.

[3:34] Granted, some of those failures can't be blamed on Mars. Some missions, especially early on, came to an abrupt end due to rockets blowing up on the launch pad, or not getting very far past Earth. But still, less than half of the missions ever sent to Mars have made it. The InSight mission hopes to improve the odds.
(music)
[3:57] Narrator: Soon after InSight launched from Earth, on Mars, one of the biggest dust storms in history swirled into life.

[4:04] Bruce Banerdt: Dust storms tend to pop up on Mars on a pretty regular basis. In fact, there's a dust storm season on Mars. Some seasons there's small dust storms, and some seasons there are huge dust storms. And we actually just got hit with one of the big ones.

[4:17] Narrator: That's Bruce Banerdt, the scientist leading the InSight mission. He and the InSight team were first alerted to the storm from the Mars Reconnaissance Orbiter, a satellite circling Mars. A rover on the ground, named Opportunity, sent photos back to Earth of the Martian sky growing dusty and dark, until the Sun disappeared in the sky.

[4:38] The storm grew until it covered most of Mars. We don't have weather like this on Earth. Our storms are located in one place, and then they drift to another area or disperse entirely. We've never, for instance, had a hurricane in the Atlantic Ocean grow and grow until it becomes a single storm enveloping most of the planet.

[4:59] But this is not the first time we've seen such a large storm on Mars. When NASA's Mariner 9 orbiter reached Mars in 1971, it saw a global dust storm that was so immense, only the tops of the tallest volcanoes could be seen peeking above the haze. The Mars Global Surveyor satellite witnessed a similar massive storm in 2001.

[5:21] Those orbiters saw the storms from high above. The Viking 1 lander, in 1977, was the first time we got to see such a big dust storm from the ground. Because Viking was actually in the storm, it also could gauge the force of the winds, which topped 60 mph.

[5:38] Some of you may be thinking of the movie, "The Martian," which saw Matt Damon's character knocked down by a raging dust storm on Mars.

[5:46] Movie clip: "The Martian" storm:

Lewis: 1200 kilometers in diameter, bearing 24.41 degrees.

Johanssen: That's tracking right towards us.

Lewis: Based on current escalation, estimated force of...8600 Newtons?

Watney: What's the abort force?

Beck: 7500.

Martinez: Anything more than that, and the MAV could tip.

Lewis: Begin abort procedure.

Watney: Let's wait it out.

Lewis: Prep emergency departure. We're scrubbed, that's an order!

[Alarm]

Lewis: Visibility's almost zero. Anyone gets lost, home in to my suit's telemetry. You ready?

Watney: Ready!

[Door opens to massive dust storm]

Watney: Commander, are you ok?

Lewis: I'm ok!

[6:27] Narrator: It makes for good drama, but the air is so thin on Mars - only 1 percent as dense as air on Earth - that even the strongest winds wouldn't knock you down. In the movie, the roaring winds that rocked their spacecraft and forced them to abort the mission would actually feel like a gentle breeze.

( sound effect: waves on a beach)

[6:54] Narrator: To understand how such strong winds wouldn't feel strong, imagine you're at the beach. A wave comes up and knocks you down. The wave is moving slowly compared to the air, but because the water is so much more dense than the air, it doesn't take much to lift you off your feet. The opposite is what happens with the thin air of Mars.

[7:13] Although the winds there don't pack a punch, they are able to pick up fine dust particles and loft them high into the air.

[7:20] Bruce Banerdt: Mars dust is extremely fine, and it's very easy to lift up in the atmosphere. And without any moisture to have the dust particles clump together, it takes a long time for it to settle out. So these dust storms tend to kick up really fast and then die off really slowly. And even after the wind's all gone, you still have a lot of dust up there which is absorbing the sun and making it kind of dark down on the surface.

[7:40] Narrator: InSight has to enter the atmosphere of Mars, descend down through it, and land on the planet's surface. This is known as EDL - Entry, Descent, and Landing. On Mars, the atmosphere is thick enough to burn you up on entry, but thin enough to make landing with a parachute extremely tricky. This is why Mars landings often include rockets firing toward the ground - so-called retro-rockets - that help slow down the descent. The InSight mission is prepared to go through Entry, Descent and Landing for a range of conditions, including a dust storm.

[8:12] Bruce Banerdt: Those little dust particles, when you're coming in at 15,000 mph, they do act as a little bit of a sand blaster. And when we designed our spacecraft, we knew that we were coming in during dust season, so we actually added about a half an inch of extra material on the heat shield, the ablative material that actually burns off as you go into the atmosphere. The calculations and the experiments that we did on the material indicated that that was more than enough to accommodate the extra erosion that we would experience if there was dust in the atmosphere. So, even if there is still dust in the atmosphere when we land, our entry system should be perfectly happy with that kind of environment, and the parachute won't even notice it.

[8:50] Narrator: It can take months for dust from such a big storm to slowly settle out of the air. If there's a lot of dust in the air when InSight lands, the biggest problem for the lander will be power generation. InSight runs on solar power. Falling dust not only blocks the sunlight, it also could coat the solar panels, causing InSight to run out of energy.

[9:13] Opportunity rover, who got caught in the dust storm, is also solar powered. It went into hibernation soon after the dust storm appeared, in order to save power.

[9:22] The power does more than run the rover: it keeps it warm on frigid Martian nights. Temperatures in Opportunity's neighborhood - the Martian equator - can dip down to -130 degrees Fahrenheit, or -90 Celsius. Without a heater, the rover could freeze to death. It's similar to running a car in the winter so the cold doesn't sap the battery charge. The Martian cold may have been what ultimately killed Opportunity's twin rover, Spirit, back in 2010.

[9:51] Opportunity is currently the longest-running mission on the surface of Mars. It's been in operation for over 14 years, since 2004, and it survived a large dust storm in 2007. That storm led to two weeks of minimal operations, including several days with no contact from the rover, in order to save power.

[10:11] Opportunity has been in hibernation now since June 10th. Dust storms do heat the air up on Mars, so it's possible Opportunity wasn't fatally damaged by the cold. In September, enough dust had settled out of the atmosphere that sunlight could penetrate through the haze and recharge the solar panels.

[10:29] While waiting for the rover to wake up, to boost the team's morale, engineers have started each day playing a song in Mission Control.

(music: " Wake Me Up, Before You Go-Go")

[10:41] "Wake Me Up Before You Go-Go" by Wham, is just one of many songs dedicated to the sleeping rover.

[10:52] Over the weeks their themed playlist has included "I Will Survive" by Gloria Gaynor, "I Won't Back Down" by Tom Petty, "Here Comes the Sun" by the Beatles, and "Dust in the Wind" by Kansas.

[11:07] Opportunity, meanwhile, remains silent and still. Mission engineers will keep listening for the rover to phone home over the next few months.
(music: "Dust in the Wind")
[11:18] What InSight will have to struggle with when it arrives on Mars is still to be determined.

[11:21] Bruce Banerdt: We have a lot more solar power generation capability than Opportunity, but I think that our design would be at best marginal against the darkest part of the dust storm. Once we get to Mars, if we have a dust storm like that again, it would be pretty nerve-wracking for us.

(" Dust in the Wind" lyrics: "Nothing lasts forever but the Earth and sky...")

[11:43] Narrator: InSight science lead Bruce Banerdt has had his heart broken by Mars before. Years ago, he worked on the Mars Observer mission.

[11:51] Bruce Banerdt: My early career I sort of was kind of a recluse. I'd go in my office, and I'd lock the door, and just work on my computer and hope nobody ever bothered me. But then somebody came and said, "Well, we need someone to work on this space mission." Or, "We need a scientist to help integrate this altimeter that is going to go to Mars on Mars Observer."

[12:08] Narrator: An altimeter is used to create elevation maps that show the heights of mountains and the depths of canyons.

[12:14] Bruce Banerdt: This was going to be the first detailed elevation map of any planet outside the Earth, and it's something that's really critical, if you want to look at what forces there are on a planetary crust. And by the time we launched, I thought, "Well, finally we're going to Mars, and all our problems are behind us." And then we got close to Mars. We did our last trajectory correction maneuver before going into Mars orbit, and we never heard from it again.

[12:42] Back in '93 I guess, which is when this was all happening, we didn't have all the fancy displays and the animations. So when we had to turn this spacecraft to do this orbit trajectory change maneuver, we slewed away from the Earth point on the radio, so we lost contact. It was supposed to fire its rockets for 40 seconds or something like that, and then turn her back around and then we reacquire the signal. We had an old CRT monitor hooked up to the DSN data feed with the signal strength just as a line across, sort of like one of those old oscilloscope displays. It turned away, and so the line goes flat at zero power. Then, 20 minutes or 40 minutes later, it's supposed to blip back up again and show our signal line. One of the young engineers on the project was keeping track of the time, had his pencil there on the screen, and says, "Right about here's where we ought to get it." We were watching, and it kept on going flat. I said, "Well, maybe we're having a little bit of trouble acquiring." And so, you're just waiting for something to happen, and it's not happening, and it's not happening. At first, there's lots of explanations why that not might not be true. And then there's fewer explanations that are still consistent with it being that long. And then maybe there's one or two things that might have gone wrong that are still not fatal, but it's a slow motion train wreck, that you're getting more and more of a sinking feeling and trying to stay optimistic, but there's always a voice in the back of your mind going, "Uh oh, this isn't good."

[14:07] We waited to acquire the signal, and it didn't show up. That flat line never did leave zero. That was a really, really horrible feeling to have worked on something for five or six years, and then suddenly it's all gone. Later on, they found a design flaw in the propulsion system, which likely allowed the fuel to mix with the oxidizer in the wrong place, and probably blow a hole in the side of the spacecraft.

[14:32] When Mars Observer was lost, we took the same payload, or part of the same payload, and started a new mission with kind of the same designs, but a little bit different spacecraft called Mars Global Surveyor, which launched about four years later. It kind of just merged from Mars Observer into Mars Global Surveyor. I ended up actually working on that project for about 20 years, and it was a great project. I mean, the MOLA maps of Mars -- if you've ever seen the map that's kind of blue and orange, that's our MOLA elevation map that I played a small part in helping to create. These were the first really high-resolution images that we had of Mars. You started revealing the actual geology of Mars at a level where you can kind of visualize as a human being, and not as somebody flying in an airplane two miles up or something. That's been one of the foundational data sets for Mars for understanding all kinds of things about that planet. That was an amazing project. That was so much fun.

[15:27] Narrator: As Bruce notes, although Mars Observer failed, the design was re-used for the successful Mars Global Surveyor. Spacecraft are often made this way. InSight, for instance, is essentially using the same architecture as the Phoenix lander that made discoveries near the Martian north pole over ten years ago. The Phoenix lander, meanwhile, rose from the ashes of the Mars Polar Lander that crashed in 1999.

(music)

[15:58] Rob Grover oversees the Entry, Descent and Landing procedures InSight needs to go through in order to land on Mars.

[16:00] Rob Grover: We can't really do full testing on Earth because the gravity is different, the atmosphere is different. We use simulation for making sure that we're going to be successful when we land on Mars. We use a method called a Monte Carlo simulation. It's named for a game of chance, which is a little bit of what EDL is.

[16:30] So when we run the Monte Carlo simulation, we actually land 8,000 times and it provides us statistics on how we'll perform. We randomize all the parameters that are used in modeling the landing, like the mass of the lander and how well the rocket engines are working. For each type of atmosphere we think we're going to land in, we run a Monte Carlo. Each flight path angle or angle we're going to hit the atmosphere we also run a Monte Carlo too. We have actually close to probably a thousand parameters. That allows us to practice the landing under multiple conditions. We do many, many, many Monte Carlos. For a single landing, we've probably run millions of times at this point over the five or so years that we've been doing this.

[17:12] There's a little bit of rolling the dice on EDL but we try to account for everything we possibly can. It's a risky part of the mission, probably one of the riskiest six and a half minutes of the mission. As EDL engineers, our job is really to try and think of every possible thing that can go wrong - everything that Mars can throw at us - and try and model that and make sure that the system will be able to handle that on landing day.

[17:33] Insight is the first mission to land during dust storm season. That makes it particularly challenging because the atmosphere affects the landing quite a bit. With the dust storm season, we could be landing in the middle of a global dust storm, or the atmosphere could be just a regular clear atmosphere, or anywhere in between. That makes a lot more variation that we have to account for when we're designing and executing the landing. So it makes it more challenging for Insight than past missions in that respect.

[18:01] Narrator: As InSight approaches Mars this November, we'll all be on the edge of our seats, watching for that signal, waiting to see if it beats the odds, and survives.

[18:11] But InSight almost died before it even left Earth.

[18:14] Bruce Banerdt: We had a lot of problems with InSight, and then we had to stand down from our launch in December of 2015, which was incredibly disappointing. It was really a dark time. It was almost Christmas, and then we had to give up suddenly on this mission.

[18:31] Narrator: More about that, next time.
(end music)
[18:34] Narrator: If you like this podcast, rate us on iTunes and Soundcloud, and share us on Facebook, Instagram, and Twitter. We're #nasaonamission. Also check out NASA's other podcasts: Gravity Assist, Rocket Ranch, What's Up, NASA in Silicon Valley, and Houston We Have a Podcast. They can all be found on NASA's podcast page or on most podcast platforms. We're "On a Mission," a podcast of NASA's Jet Propulsion Laboratory.

[run time: 19:09]

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October 29, 2018 Episode 1: Getting to Mars is Hard The InSight mission is heading to Mars, but many spacecraft have died trying to get there. The current record for Mars missions is 18 successes, and 25 failures. InSight hopes to improve the odds.

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Does NASA have a Mars Pathfinder Replica 

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Does NASA have a Mars Pathfinder Replica 

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Here's the real thing! There really is a real pathfinder that could be used on Mars if an astronaut was to be stuck there like Watney. This article also talks about how replicas of each model is still kept in NASA just incase of emergency while in space. It makes it easier for them to fix during an emergency because they can physically see in-front of them what's going on and how to fix it.

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Warning: Spoilers ahead if you haven't seen "The Martian" movie or read the book.

Stranded alone on a freezing planet 140 million miles away from Earth is not a situation you'd want to find yourself in, especially with no way to phone home.

That is, of course, exactly what happens in the " The Martian" to fictional astronaut Mark Watney, who understands his survival depends on talking to people back on Earth.

Luckily, Watney knows his NASA history - so he locates and digs up Mars Pathfinder, a spacecraft NASA actually launched back in 1996. After a little tweaking, he uses the robot to communicate with engineers through a replica of Pathfinder at NASA's Jet Propulsion Laboratory.

It turns out this plan would probably work in real life because NASA really does have a working replica of Pathfinder. The spacecraft would need to be "turned on and dusted off," NASA's director of planetary science Jim Green told Tech Insider, but it does exist.

So NASA really could theoretically use it to communicate with a stranded Martian astronaut. He or she would, however, have to dig Pathfinder out of almost two decades' worth of grit blown around by wind and dust storms, then get it working again.

It's not a one-off occurrence: NASA builds a working replica of every spacecraft it launches. That way, in case something goes wrong afterward, engineers can troubleshoot the problem on Earth, come up with a fix, and send a patch to the identical robot in space.

The Pathfinder replica came in handy, for example, when NASA scientists discovered a bug in some of the computer code in the real thing, not long after it landed on Mars in 1997. They recreated the problem in the replica, and then worked out a way to debug it. The corrective instructions engineers sent to the Pathfinder on Mars fixed the bug.

It goes to show that, while NASA scientists and engineers are some of the best in the business, they can't anticipate everything that can go wrong in space. It pays to have a spare that's not 140 million miles away.

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There really is an abandonded spacecraft on Mars that you could use to communicate with NASA

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Warning: Spoilers ahead if you haven't seen "The Martian" movie or read the book. Stranded alone on a freezing planet 140 million miles away from Earth is not a situation you'd want to find yourself in, especially with no way to phone home.