• What are the mission spacecraft requirements?

Add your name to one team only, but feel free to explore what your fellow learners post about the other missions.

Add your name to one team only, but feel free to explore what your fellow learners post about the other missions.

• What are the mission spacecraft requirements?

Add your name to one team only, but feel free to explore what your fellow learners post about the other missions.

• What are the mission spacecraft requirements?

Secondary: Using AI to improve our selection process of collected space data, allows our scientists to produce useful analysis and research on data. Saving man hours and funding.

Downlinking efforts made more efficient as effective:ineffective image ratio is reduced.

Software caan be used in maritime monitoring, responses to climate disasters.

1: According to publically available information, HERA requires 712 Watts* of power when the spacecraft is orbiting Dimorphos, this will be provided by 2 x 5 meter long solar panels consisting of 1600 individual solar cells, covering an area of 14 square meters*. Once HERA is orbiting Dimorphos it will be roughly 2.4 Astronomical units (AU) from the sun & should receive roughly 17% of the sunlight that a satellite would receive in earths orbit & would produce approxiamately 800 Watts of avaliable power which covers the total requirements of the spacecraft & mission requirements.

2: The power supply solution for this mission will be provided by solar panels, as the trajectory of the mission will remain within Jupiters orbit, therefore solar panels can provide the necessary power albeit at a diminished rate, as the power of sunlight per square meter will reduce as the distance from the sun increases.

Trade offs: Solar panels are ideal in this instance as the spacecraft is remaining relatively local but considerations must be made for the deployment of the solar panels & the total amount of power that has the potential to produce.

(1400 x 14 = 19600 watts total power. / 100 = 196 watts x 17 = 3.332 watts available from sun light @ 2.4 AU) azurspace solar panels have an efficiency range of 28 - 32% at the current date & time which allow for a maximum power generation of just over 1KW (1066 watts) any additional power will need to be managed by the power control systems by either charging batteries, radiating it off as heat or adjusting the atitude control of the panels after the initial deployment to reduce power generation & provide over voltage protection (OVP) .The best trade off is the aviodance of the expense & legislative requirements of a nuclear power system. Win win…

3: Power management protocols: I’ll need to do some more research on this bit.

Hopefully, I’m along the right lines but I’m happy for any discussions. Cheers, James.

*Refs

https://en.wikipedia.org/wiki/Hera_(space_mission)

https://www.esa.int/Space_Safety/Hera

https://www.azurspace.com/index.php/en/products/products-space/space-solar-cells

-      To make use of AI to improve the way satellites collect, analyse and distribute data, with the initial focus on pre-empting weather disasters so measures can be made to protect the earth. 

-      To make use of AI to ensure that the data that is collected and downlinked to earth is of an excellent standard and of scientific merit.

-      To reduce the amount of unusable data is downlinked, which would reduce costs (energy, financial and labour) by omitting the stage where staff have to sift through unusable data of little to no scientific use – economic, science and R&D benefits.  The aim is to improve efficiency, efficacy and feasibility of data. 

-      The technology aims to operate between the space environment and Earth.

Mission Spacecraft Requirements

The primary mission spacecraft requirements are:

-          The link budget must focus on ensuring that communication is reliable over a long distance and that loss parameters are calculated accurately and include a reasonable Margin, based around the size of satellite and Orbit chosen for the Earth Observation task.

-          An appropriate payload should be chosen to satisfy the requirements to both gather data and to transmit the data.  The bus should be compatible with the payload – for this mission Communications, particularly data storage and the up-down link antenna are a priority.

Educational Engagement: It provides a platform for schools and amateur radio operators to receive real-time telemetry and interpret data, helping students learn about satellite operations, radio communication, and space environments.

Amateur Radio Communications: FUNcube-1 supports the amateur radio community by providing a U/V linear transponder, which allows licensed amateur radio operators to conduct voice communications and digital data transmissions. This transponder operates in a way that permits communications even when the satellite is in eclipse, a unique feature in small educational CubeSats.

Welcome to the FUNcube Web Site

The SSETI Handbook (funcube.org.uk)

• close to sun so solar panels appropriate.

• roughly 90min orbits, so regular eclipse periods and regular charge/discharge of battery

  • not a long mission - probably 5yrs max, so this isnt too important

• needs to be low cost as not a long mission

• AI algorithms are processor heavy and so require a good amount of wattage

• Imagers are also power heavy

Use onboard AI to filter and prioritise better data, so that transmission of ad images is reduced. This will reduce the downlink and transmission reqs of the satellite

Demonstarte and develop AI in Space:

Demonstrate ai capability to classify and assess EO data. Also use mission to optimise the usage of AI based on its strength and weaknesses

Support climate and environmental monitoring:

Provide data to assist in monitoring climate and environmental changes. Mission aims to overall improve EO data collection and protect the earth.

Advance ai for EO:

Show the economic and scientific potentential of AI in satellites, and promote further R&D into it

• Must filter EO data to prioritise high quality and valuable data

• Must detect and get rid of low quality data

REQ-002 - data classification

• Must classify objects and structures based on pre-defined criteria

• Classification is to support monitoring and assessment goals

REQ-003 - Prioritised data transmission

• Must prioritise downlinknig of processed and valuable data to maximise bandwidth efficiency

• Must be adaptable to differetn mission phases and objectives

REQ-004 - Energy management

• Must have a power system campable of supporting the continuous full-operation of the spacecraft

• Must ensure power availability during eclipse

REQ-005 - Comms bandwidth and latency

• Must support high-bandwidth comms like to transmit images and data to Earth efficiently

• Down latency must be minimised

REQ-006 - Attitude control

• Must maintain an attitude suitable for EO to maximise image quality and rate

• Must ensure accurate pointing for consistent image capture

• Must be stable enough to capture clear imagery

REQ-007 - Conditional resilience

• Must be able to operate within the expected (+margin) radiation levels and temp variations

• Must be resilient to induced damage

REQ-008 - Reliability and redundancy

• Must ensure high reliability to achieve continuois operation over planned duration

• Critical systems must include redundancu in case of failures

REQ-009 - EOL

• Must adhere to propel EOL disposal and minimise space debris

• Is there any object of interest relatively close by that can be analysed using the same sensors?

• What would the additional resource requirements be (extra propellant, higher initial power budget to account for more solar panel degredation of a longer mission)?

• Because these obectives are not critical it might be possible to use up the safety margins of the original design, rather than modifying the spacecraft.

• How can the spacecraft be decomissioned if it fails halfway through the secondary objective?

I'm sure I missed some, happy to discuss!

Source: "Modular Power Standard for Space Explorations Missions", https://ntrs.nasa.gov/api/citations/20170001302/downloads/20170001302.pdf

• Must have a power source to meet operational needs, including AI processing and imaging payload

• Must provide sufficient energy during both daylight and eclipse periods

• Must maintain sufficient margins to account for EOL degradation

• Must sustain MR throughout operational lifecycle

Power System

Solar panels with battery storage

Advantages

• Reliable and efficient in LEO with consistent sunlight (roughly 2/3rd of the time)

• Tandem solar cells (30% efficiency) can meet high power demands and are also lightweight and cost effective

• Proven technology and minimal complexity

Disadvantages

• Rely on sunlight which is not all the time, thus requires batteries also

• Batteries add mass and have limited charge-discharge cycles

Power Management Protocols

• Operational Modes

  • Nominal - Full operation, AI, Imaging, comms, CPU, battery charging, all powered by solar panels

  • Eclipse - Critical systems, AI, Thermal, minimal comms, powered by batteries

• Budgeting

  • Power to be allocated based on operational priorities

  • Margin to account for uncertainties and degradation over time (Microsoft Word - AD 5 Margin philosophy for science assessment studies 1.3)

• EOL Planning

  • Account for solar panel degradation over time and reduced battery capacity

Maximum Power Point Tracking (MPPT) - Optimises energy collection from the solar panels and adjusts the system's operational mode (educational, amateur radio, safe, receiver only) based on the available power. This ensures efficient energy conversion and battery charging.

EPS – If a failure develops in the rechargeability of the battery, the EPS is still able to provide power from the solar panels ensuring systems can still be powered, albeit in sunlight-only mode.

I think the microcontroller in the EPS would have the job of voltage regulation and battery protection? Unsure on this.

Battery (Li-ion) – Two-cell 7.6V battery with a capacity of 2600mAh, stores energy generated by solar panels, critical for proving power during periods of eclipse when solar panels are ineffective. Offers high-energy density but has limited life-cycle. Over time the rechargeability will degrade. If battery charge is low during eclipse the CubeSat will enter “safe mode” to reduce power demands until sunlight returns.

• Since this spacecraft is very small, and its functions are only monitoring and comms, it won't require much power - I would estimate around 50-100W.

• A constant supply of power is required to keep sensors running and telemetry transmitting back to the ground continuously.

Power supply solutions / trade-offs

• Since this spacecraft will remain in Earth orbit, solar panels are sufficient for its needs and preferable to nuclear power. Solar panels are smaller, cheaper, lighter, and far less complex than nuclear power systems. The solar panels should be articulated to remain at an optimum angle to the Sun.

• Since the spacecraft will be in eclipse conditions ~50% of the time, a battery is needed to store and provide power when the solar panels cannot. A battery should suffice (compared to fuel cells) because this is a relatively short-term and non-critical mission, so reliability and lifespan over multiple cycles is less of a consideration.

Power management protocols

• When in direct sunlight, the spacecraft should draw power from its solar panels. It should operate all sensors, and send telemetry regularly to the ground, as well as performing required spacecraft maintenance operations such as attitude adjustments. It should use the remaining power to charge the batteries.

• When in eclipse conditions, the spacecraft should do all of the above, but drawing power from the batteries instead of the solar panels.

• When power is running low in eclipse conditions, the spacecraft should go into power-saving mode, in which only critical functions continue. This will conserve remaining power until the spacecraft is back in sunlight again.

Solar panel size calculations

Assuming:

• 70W power needed

• Sun provides 1.4kW/m² in Earth orbit

• Solar panels operate at 10% efficiency

• Spacecraft spends 50% time in eclipse conditions

1400 x A x 0.1 x 0.5 = 70 -> A = 1

Therefore this spacecraft needs solar panels of at least 1m².

We should use a low-gain antenna (LGA) in order to have wider non-directional signal coverage over the surface of the earth. This also has the benefits of being a simpler and cheaper design.

Type of polarisation

We should use circular polarisation, to avoid the atmosphere's de-polarisation effects (Faraday rotation)

Other considerations

• Will the signal be strong enough, on such a small cubesat?

• What frequency should we use, considering interference and regulatory standards?

The receiving antenna itself for this mission takes the form of a small dongle that can be plugged into a computer via a USB port.

The software to decode and analyse this data is available open-source at github.com/funcube-dev/funcubeLib. This means that it is free for anyone to download and use, and the source code is also available for programmers to read and modify for their own education. This software also includes a graphical user interface (GUI) which provides a platform on which you can track and analyse the data receiced.

Kind Regards,James.

If we want accurate positioning data to be included in the data transmission to Earth, we should include a GPS sensor, as this will provide extremely accurate positioning data.

Launching a CubeSat into orbit requires careful budgeting to avoid overspending. I think this mission requires a bit of shopping around, as there is not necessarily a need for a dedicated launch vehicle.

For example, a rideshare option with SpaceX typically costs at least $300,000 USD — however, this is their flat rate for any payload under 50kg. It appears that Exolaunch offers a more affordable option, with pricing around $50,000 for a 10x10x10cm, 1 kg CubeSat.

The best option, and closest to home, is Alba Orbital. They organise rideshares and have sent up over 41 satellites with Rocketlabs and SpaceX since 2019. Alba Orbital is the most cost-effective, offering a pocket cube (half the volume of our satellite) for 25,000 euros, though a full 10x10x10 cm CubeSat costs 40k euro. Both Rocket Lab and SpaceX are used as launch providers, providing added mission assurance. I think Alba Orbital gets around SpaceX’s minimum payload fee by acting as the middleman, reserving slots for smaller satellites, and bundling them all together as one payload.

So, our launch vehicle would likely be the Electron or the Falcon 9.