Raspberry Pi Zero powers CubeSat space mission
GASPACS (Get Away Special Passive Attitude Control Satellite) CubeSat is a NASA-sponsored mini-satellite project built by students from Utah State University (USU). The team behind it think it’s the first satellite to use Raspberry Pi Zero as its flight computer.
How does it work?
By “mini-satellite” we mean tiny. CubeSats are made up of cubic modules measuring just 10cm along each side, and this particular CubeSat consists of just one of these modules.
GASPACS’ primary mission is to test the deployment of an experimental metre-long inflatable boom, and also to find out whether the boom works as intended to help the satellite stabilise itself. The CubeSat hitched a ride on the International Space Station into low-Earth orbit, and has been transmitting photographs taken with a Raspberry Pi Camera back to Earth.
A DFRobot Beetle microcontroller board is responsible for checking the Raspberry Pi Zero is still alive. The Zero sends a “heartbeat” signal every few seconds, and if this ever stops, the Beetle power-cycles it, because “try turning it off and on again” works just as well in space.
How is it made?
- Raspberry Pi Zero W
- Raspberry Pi Camera Module 2
- Custom interface board with LSM303AGR, real-time clock DS3231SN, DFRobot Beetle “watchdog”, analog-to-digital converter ADC128S102, and a custom burn wire circuit release mechanism for the boom
- EnduroSat battery, transceiver, and antenna
- EnduroSat solar panels with sun sensors and temperature sensors
- Custom “aeroboom” payload (the experimental self-stabilising boom)
The flight software, CubeWorks, is open source and can be found on GitHub. Over 80% of the software powering the satellite is written in Python.
Where is the satellite now?
GASPACS CubeSat was deployed from the International Space Station in January and made contact with a ground station in Japan within an hour. Since then, ground stations all around the world have reported picking up GASPACS’ beacons.
Its self-stabilising inflatable boom was successfully deployed about 45 minutes into the mission, and naturally GASPACS snapped a couple of selfies of it with its Raspberry Pi Camera. When GASPACS passed over the custom-built ground station on the USU campus, it transmitted the first load of photographs from its journey to the team back at home.
You can keep track of the GASPACS CubeSat mission, see the photos it’s taking, and follow its journey orbiting Earth on Twitter at @GASPACS_CubeSat.
I have watched reports of other cubesats by amateur radio operators, and this is so interesting that Raspberry Pi has made history by going into outer space. Go, Pi, go.
Actually, the team designed around the probability that the SD card would get corrupted. It has 4 redundant versions of the code, each built to move on to the next if they get corrupted.
Source: I am on the team
And then the SD card gets corrupted.
Raspberry Pi Staff Liz Upton
Not if you buy a decent one. We recommend SanDisk – there is an ENORMOUS delta in quality between different vendors.
I wondered about this. I haven’t ever considered SD cards susceptibility to radiation / SEU in space because I don’t think anybody ever considered it for missions / TRL.
In the case of a Pi Zero, I’m sure they have engineered the cubesat to shield it well.
You’ld be suprised that no shielding at all was used in the design, only the natural sheilding of the Earth’s magnetic field. Part of the mission was to test how resilient the pi actually is to the space environment. The majority of radiation induced problems are known as single event upsets. For the most part, these can be reversed by rebooting the pi, and this is the purpose of the watchdog mentioned in the article.
I would be more concerned about the SD card mentioned in the original comment. SEUs in these might produce a more permanent failure condition, magnetic field or not the ionosphere has far more charged particles pinging around than down here.
Raspberry Pi Staff Liz Upton
There are a lot of Raspberry Pis on the ISS, all of which use SD cards (not just the Astro Pi units; there are a lot used operationally as well). They’re used for a significant length of time, and are flight-tested.
100% agree Liz. I only used SanDisk. Never had issues. Even on my Gen 1 RPi that is still, years later, connected to my printer on the same card. Mind you I always shut down my RPi correctly. Any PC could corrupt it’s drive if you just yank the power out if you do not shut it down first.
AX.25 packets can be heard around 437.365MHz. It’s interesting to see the aero boom idea for passive stabilisation, as opposed to the established gravity gradient booms.
It seems only applicable to short missions in LEO because by its nature it will increase orbital decay, but fantastic work, good to se Pi Zero up there, I guess the 40nm die is an advantage in space tech!
Ok! The guys at USU put a satelite in orbit and meanwhile the people here are dicussing about SD cards. OMG!!!
I worked on a CubeSat project as a grad student at USU years ago, so it’s fascinating to see the advances made for this launch – especially the use of a Pi Zero. Congrats to the undergrad team and the Raspberry Pi Foundation. Go Aggies!
My concern on it is also on the SD card.
And i tell you why. I built a cluster with 60 raspberrys (lemp stack with high availability) for an OSINT project.
The SD were pretty expensive at the time and from a known brand. They started dying from the PHP, python and mysql/mariaDB queries. Not too much.
Different brands used, from kingston to sandisk. The only thing remarkable is that i was monitoring and knowing when they died and since DB was replicated i could just change cards (from pi to garbadge).
I had also 2 cards not on DB that suddenly died.
This is really impressive! Curious how you guys protected your Pi from the elements in space? Did you use conformal coating? I’m also working on a project to send a Pi zero to space!
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