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NASA's Climate Orbiter was lost September 23, 1999

By Robin Lloyd
CNN Interactive Senior Writer

(CNN) -- NASA lost a $125 million Mars orbiter because a Lockheed Martin engineering team used English units of measurement while the agency's team used the more conventional metric system for a key spacecraft operation, according to a review finding released Thursday.

The units mismatch prevented navigation information from transferring between the Mars Climate Orbiter spacecraft team in at Lockheed Martin in Denver and the flight team at NASA's Jet Propulsion Laboratory in Pasadena, California.

Lockheed Martin helped build, develop and operate the spacecraft for NASA. Its engineers provided navigation commands for Climate Orbiter's thrusters in English units although NASA has been using the metric system predominantly since at least 1990.

No one is pointing fingers at Lockheed Martin, said Tom Gavin, the JPL administrator to whom all project managers report.

"This is an end-to-end process problem," he said. "A single error like this should not have caused the loss of Climate Orbiter. Something went wrong in our system processes in checks and balances that we have that should have caught this and fixed it."

The finding came from an internal review panel at JPL that reported the cause to Gavin on Wednesday. The group included about 10 navigation specialists, many of whom recently retired from JPL.

"They have been looking at this since Friday morning following the loss," Gavin said.

The navigation mishap killed the mission on a day when engineers had expected to celebrate the craft's entry into Mars' orbit.

After a 286-day journey, the probe fired its engine on September 23 to push itself into orbit.

The engine fired but the spacecraft came within 60 km (36 miles) of the planet -- about 100 km closer than planned and about 25 km (15 miles) beneath the level at which the it could function properly, mission members said.

The latest findings show that the spacecraft's propulsion system overheated and was disabled as Climate Orbiter dipped deeply into the atmosphere, JPL spokesman Frank O'Donnell said.

That probably stopped the engine from completing its burn, so Climate Orbiter likely plowed through the atmosphere, continued out beyond Mars and now could be orbiting the sun, he said.

Climate Orbiter was to relay data from an upcoming partner mission called Mars Polar Lander, scheduled to set down on Mars in December. Now mission planners are working out how to relay its data via its own radio and another orbiter now circling the red planet.

Climate Orbiter and Polar Lander were designed to help scientists understand Mars' water history and the potential for life in the planet's past. There is strong evidence that Mars was once awash with water, but scientists have no clear answers to where the water went and what drove it away.

NASA has convened two panels to look into what led to the loss of the orbiter, including the internal peer review panel that released the Thursday finding. NASA also plans to form a third board -- an independent review panel -- to look into the accident.

Metric system used by NASA for many years

A NASA document came out several years ago, when the Cassini mission to Saturn was under development, establishing the metric system for all units of measurement, Gavin said.

The metric system is used for the Polar Lander mission, as well as upcoming missions to Mars, he said.

That review panel's findings now are being studied by a second group -- a special review board headed up by John Casani, which will search for the processes that failed to find the metric to English mismatch. Casani retired from JPL two months ago from the position of chief engineer for the Lab.

"We're going to look at how was the data transferred," Gavin said. "How did it originally get into system in English units? How was it transferred? When we were doing navigation and Doppler (distance and speed) checks, how come we didn't find it?"

"People make errors," Gavin said. "The problem here was not the error. It was the failure of us to look at it end-to-end and find it. It's unfair to rely on any one person."

Lockheed Martin, which failed to immediately return a telephone call for comment, is building orbiters and landers for future Mars missions, including one set to launch in 2001 and a mission that will return some Mars rocks to Earth a few years down the line.

It also has helped with the Polar Lander mission, set to land on Mars on December 3 and conduct a 90-day mission studying martian weather. It also is designed to extend a robotic arm that will dig into the nearby martian soil and search for signs of water.

NASA managers have said the Polar Lander mission will go on as planned and return answers to the same scientific questions originally planned -- even though the lander will have to relay its data to Earth without help from Climate Orbiter.

Error points to nation's conversion lag

Lorelle Young, president of the U.S. Metric Association, said the loss of Climate Orbiter brings up the "untenable" position of the United States in relation to most other countries, which rely on the metric system for measurement. She was not surprised at the error that arose.

"In this day and age when the metric system is the measurement language of all sophisticated science, two measurements systems should not be used," Young said.

"Only the metric system should be used because that is the system science uses," she said.

She put blame at the feet of Congress that she said has squeezed NASA's budget to the point that it has no funds to completely convert its operations to metric.

"This should be a loud wake-up call to Congress that being first in technology requires funding," she said, "and it's a very important area for the country."

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RELATED SITES:
Mars Climate Orbiter
Mars Global Surveyor
Mars Meteorite Home Page (JPL)
Macquarie University
Stromatolites
Fossil Record of the Cyanobacteria

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Metric mishap caused loss of NASA orbiter

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NASA's Climate Orbiter was lost September 23, 1999 By Robin Lloyd CNN Interactive Senior Writer (CNN) -- NASA lost a $125 million Mars orbiter because a Lockheed Martin engineering team used English units of measurement while the agency's team used the more conventional metric system for a key spacecraft operation, according to a review finding released Thursday.

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Summer Research Program for Science Teachers
Ann Meyer
New Explorations into Science, Technology and Math

August 2005

M&M's and the Scientific Method

Grade Levels: High School (can be adapted for Middle School students)

Introduce the scientific method including terminology

Provide a fun activity for students to experience how the scientific method is used

Stage and duration of activity: 50 minutes

Supplies: One regular sized bag of M&M's for every 2 to 3 students

One regular sized bag of M&M's for demonstration

One bag of peanut M&M's and one large bag of M&M's

Introducing M&M Activity to Class

The teacher holds up a bag of regular sized M&M's. The teacher asks a question to begin the discussion-- What things might we want to know about this bag of M&M's? Students will respond with a variety of inquiries-- How many M&M's are in the bag? What color M&M's are in the bag? How many of each color M&M are in the bag? How much does one M&M weigh? How much does the bag weigh?

The teacher chooses one question. A useful introductory question is-- How many M&M's are in the bag? Students guess the number of M&M's. Using the framework of students' guesses, the teacher introduces scientific terminology. For instance, during the discussion of answers to the question of how many M&M's are in the bag, the numbers put forth are hypotheses. At this point, the teacher should write the definition of the new scientific term on the board and have students copy it onto their definition sheet. In addition, the teacher writes 'Hypotheses' on the board and lists the numbers volunteered by students underneath the word. After asking many if not all of the class to respond with a hypothesis about how many M&M's are in the bag, the teacher asks- How do we determine which hypothesis, if any, is correct? Usually, a student will ask the teacher to open the bag. The teacher then introduces the concept of data collection to determine if one's hypothesis is correct. The teacher opens the bag, counts the number of M&M's and writes 'Data' under which she writes the number counted in her bag. Following the introduction, students form small groups to complete the M&M activity.

Break students into groups of 2 or 3 students. Hand out directions (see Handout). Read directions aloud while students follow along. Allow students about 15 minutes to complete the activity.

The teacher brings the class back together and asks all of the groups about their questions and the answers that were found. At this point, the teacher asks every group to fill out a data table about the multiple bags of M&M's- How many M&M's are in the bag and How many of each color M&M are in the bag. By collecting the data from all of the groups, the teacher introduces the concept of multiple trials. (One discovers that the number of M&M's per bag is not constant nor is the number of each color in the bag resulting in variation between M&M bags and the potential for calculations using the data.)

Example Table for Board:

Using the data from the class, the teacher is able to address the idea of variance in data. To follow up the teacher asks- From our data, what would be an accurate way to determine the number of M&M's in a random bag I pick up at the grocery store? The average of the numbers provides an accurate description of the number of M&M's in a randomly chosen bag. Also, the average number of each color M&M per bag may be calculated. In addition to the average calculations, the class determines the median and mode for the total number of M&M's per bag and/or the number of each color of M&M per bag. Students may also graph the data in histograms and/or pie charts (color-coded graphs follow easily from the M&M colors).

Extending the concepts one step further, the teacher brings out a bag of peanut M&M's and asks- Do we know anything about this bag of M&M's based on our data? Additionally, the teacher may want to bring out a large bag of M&M's and ask- Do we know anything about this bag of M&M's based on our data? At which point the teacher introduces inference. Often, one group determines the weight of a single M&M during the group activity. If not, the teacher weighs an individual M&M. Dividing the weight of the large bag by the weight of a single M&M determines the number of M&M's in the large bag (disregarding the weight of the bag).

National Standards

Teaching Standard A: Teachers of science plan an inquiry-based science program for their students.

Content Standard A: As a result of activities in grades 9-12, all students should develop abilities necessary to do scientific inquiry, understandings about scientific inquiry

Program Standard A: Teaching practices need to be consistent with the goals and curriculum framework.

New York City Science Standards

Standard S5 (a-f) The students demonstrates scientific inquiry and problem solving by using thoughtful questioning and reasoning strategies, common sense and conceptual understanding from Science Standards 1-4, and appropriate methods to investigate the natural world.

Standard S7 (a-d) The student demonstrates effective scientific communication by clearly describing aspects of the natural word using accurate data, graphs, or other appropriate media to convey depth of conceptual understanding in science; that is, the student: represents data and results in multiple ways, such as numbers, tables, and graphs, drawings, diagrams, and artwork; and technical and creative writing.

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Summer Research Program for Science Teachers Ann Meyer New Explorations into Science, Technology and Math August 2005 M&M's and the Scientific Method Grade Levels: High School (can be adapted for Middle School students) Introduce the scientific method including terminology Provide a fun activity for students to experience how the scientific

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A hypothesis is a tentative answer to a scientific question. A testable hypothesis is a hypothesis that can be proved or disproved as a result of testing, data collection, or experience. Only testable hypotheses can be used to conceive and perform an experiment using the scientific method.

In order to be considered testable, two criteria must be met:

It must be possible to prove that the hypothesis is true.

It must be possible to prove that the hypothesis is false.

It must be possible to reproduce the results of the hypothesis.

All the following hypotheses are testable. It's important, however, to note that while it's possible to say that the hypothesis is correct, much more research would be required to answer the question " why is this hypothesis correct?"

Students who attend class have higher grades than students who skip class. This is testable because it is possible to compare the grades of students who do and do not skip class and then analyze the resulting data. Another person could conduct the same research and come up with the same results.

People exposed to high levels of ultraviolet light have a higher incidence of cancer than the norm. This is testable because it is possible to find a group of people who have been exposed to high levels of ultraviolet light and compare their cancer rates to the average.

If you put people in a dark room, then they will be unable to tell when an infrared light turns on. This hypothesis is testable because it is possible to put a group of people into a dark room, turn on an infrared light, and ask the people in the room whether or not an infrared light has been turned on.

It doesn't matter whether or not you skip class. This hypothesis can't be tested because it doesn't make any actual claim regarding the outcome of skipping class. "It doesn't matter" doesn't have any specific meaning, so it can't be tested.

Ultraviolet light could cause cancer. The word "could" makes a hypothesis extremely difficult to test because it is very vague. There "could," for example, be UFOs watching us at every moment, even though it's impossible to prove that they are there!

Goldfish make better pets than guinea pigs. This is not a hypothesis; it's a matter of opinion. There is no agreed-upon definition of what a "better" pet is, so while it is possible to argue the point, there is no way to prove it.

Now that you know what a testable hypothesis is, here are tips for proposing one.

Try to write the hypothesis as an if-then statement. If you take an action, then a certain outcome is expected.

Identify the independent and dependent variable in the hypothesis. The independent variable is what you are controlling or changing. You measure the effect this has on the dependent variable.

Write the hypothesis in such a way that you can prove or disprove it. For example, a person has skin cancer, you can't prove they got it from being out in the sun. However, you can demonstrate a relationship between exposure to ultraviolet light and increased risk of skin cancer.

Make sure you are proposing a hypothesis you can test with reproducible results. If your face breaks out, you can't prove the breakout was caused by the french fries you had for dinner last night. However, you can measure whether or not eating french fries is associated with breaking out. It's a matter of gathering enough data to be able to reproduce results and draw a conclusion.

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A hypothesis is a tentative answer to a scientific question. A testable hypothesis is a hypothesis that can be proved or disproved as a result of testing, data collection, or experience. Only testable hypotheses can be used to conceive and perform an experiment using the scientific method.

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people with a high exposure to uv light will have a higher frequency of skin cancer.