How to Make a CubeSat
orbitalindex.com
orbitalindex.com
Many of these open source projects actually use consumer / hobbyist grade components instead of using commercial aerospace-grade components. The commercial hardware for cubesats is made with a specific manufacturing process that makes them resistant to radiation in space. However, this increases manufacturing costs. Also, most of the radiation resistant hardware being sold is sort of slow / outdated. The solution some open source projects came up with was to just take components from Mouser and run their own radiation tests on it then choose the ones that fared good enough to be used in space. That way they can make satellite boards for way cheaper.
Another interesting development is there are some startups now offering sub 50k launches for cubesats, such as launcher space. They essentially buy launches from SpaceX then outfit it with hardware to launch a massive amount of cubesats at once. As a result of the number of cubesats they’re able to fit on one launch, the prices are now relatively cheap compared to the hundreds of thousands if not millions required in the past. However, most of these startups are heavily subsidizing the cost using VC money so these low prices won’t stay forever.
Also, if anyone has any questions about cubesats feel free to AMA. I work at Isomer space which is a not for profit building cubesats. I would love to answer any questions about cubesats or our work.
In terms of scientific, I think it's best to think of CubeSats as a floating lab. You can basically stick whatever you want on there (size permitting). One thing you can do is stick cameras on there to track climate change through a cluster of tiny cheap CubeSats. Another is to put sensors to measure different particles in space. CubeSats are also useful for testing out new forms of propulsion like ion thrusters. You can also use them to test new materials in space. I have even heard putting bacteria inside CubeSats to see how they react in space. In general, CubeSats are just insanely useful for collecting sensor data for research and putting items in space to see how they react.
The big appeal though is you can do all of this stuff I mentioned for the fraction of the cost of a normal satellite. As a result, CubeSats are great for smaller companies or researchers who don't have unlimited cash to spend on a big satellite.
Hope all this info helps!
Second question (somewhat related to first) — can a cubesat stream video to a server on earth? (Or does one need a ‘big Sat’ to do video streaming?
For question 1, I do think you could use it for astrophotography. You could probably capture pictures of the stars if you have stabilization on the CubeSat. However, the photos would probably be similar to the photos taken of space from the ISS. What I mean by this is you might be able to take photos of the stars, but it wouldn't be able to see anywhere as far out as Hubble. I know a bunch of CubeSats use smartphone quality cameras so you would probably get a decent photo that might make a nice desktop wallpaper, but it wouldn't really compare to a bigger satellite. It would show an overview of the stars, but it wouldn't be significantly different from existing images imo except maybe it being from a different perspective. As far as zooming in, that would actually be kind of hard due to space constraints. CubeSats are small, like really small (10 cm x 10 cm x 10 cm in some cases). So it would be hard to fit any substantial zoom lens system in there. That might make getting ultra close ups hard. Maybe as camera tech improves in the future what you are suggesting would be possible though. Aiming it at a specific planet also might be a bit of a challenge. CubeSats mostly don't have propulsion (although we are adding an ion thruster in ours). They can use reaction wheels to rotate though. However, accurately rotating it towards a tiny planet in the sky could be hard. However, I will say you could go for a really big CubeSat design and fit a good camera system in that. Then if you solve the aiming issue you could get some really cool images that are zoomed in on planets / stars.
For question 2, we actually considered trying this. I had the idea to live stream the satellite on Twitch. We discovered that livestreaming it was hard. If you are sending data from the CubeSat to earth, the data transmission is very slow. That basically rules out livestreaming. Maybe you could transmit it to a big communications sat in orbit which then sends it to Earth. However, I suspect the data transmission speed might still be less than ideal. Plus, using a communications sat network (like Iridium) could be expensive. Let's say though communication tech gets better and you can transmit directly to Earth at a fast speed. There is still are two major issues. Regulations and getting ground stations. Every single ground station (basically an antenna on Earth that gets data from space) requires you list it on your FCC application. If it involves ground stations in other countries (especially countries the USA isn't friendly with) it can get very messy from a regulations perspective. Also, getting those partnerships to begin with can be messy as well. There are some networks like SatNogs that do allow for receiving data from volunteer ground stations in other countries. Although, I don't know if they would really be practical for livestreaming due to coverage. I know Amazon has some offerings where they let you access their ground station network that might allow for livestreaming one day. However, I haven't really explored too much into it. I also haven't heard of any teams using AWS Ground Station personally though. Honestly, you'd be forced into using Iridium regardless due to coverage being shoddy for ground stations. Overall though, I think the data speeds just aren't there yet to livestream, at least not with LoRa (which is the protocol a lot of teams use for transmission).
Best bet is if starlink, oneweb, etc. provide a service for satellites to relay your data back.
Also, for the satellite transmission via Starlink, I don't think Starlink / OneWeb offers that yet for CubeSats (might be wrong though). I do know Iridium allows for it though. However, as I mentioned earlier in the prev comment, the data speeds might suck still (could be wrong here too) and it costs a lot of money. I do think some ground stations would have wanted money too. We didn't actually need to livestream as it was just some fun PR trick. We ended up deciding it wasn't worth it in terms of cash / effort.
As far as over subscription, it depends. If you are using a public ground station network then its an issue. If you are partnered with no public ones then it's not as big of an issue. We were thinking of private ones only because public ones would not allow this kind of thing. So over subscription just didn't even matter for us really.
If I may ask another question: do you think the CubeSat ‘form factor’ (10x10x10 cm-cube) can have enough propulsion (combined with some gravtiy-assist) to be able to get into an orbit around another planet or another moon in our solar system? Meaning, can a CubeSat be sent to .. say Titan, as a probe (say a ‘mini-Cassini’).
(Just curious to understand whether cheap ‘CubeSats’ can be used as tiny probes for the entire solar system)
Thank you!
As a whole though these camera system are mostly used for Earth as it's an easier target. Space images are more like astrophotography grade and not Hubble grade.
If you want an example of a good cubesat camera here are some. https://dragonflyaerospace.com/products/ I should note though that these would not generally fit inside a 1U given their smallest one takes up 1U worth of space.
> The solution some open source projects came up with was to just take components from Mouser and run their own radiation tests on it then choose the ones that fared good enough to be used in space. That way they can make satellite boards for way cheaper.
Isn't there a requirement for all cube-sats to pass radiation tests / shock tests or whatever for them to be accepted for launch?
From what I've read researching this stuff, the sats themselves aren't necessarily difficult or expensive to build, but its because of this testing / component requirement that makes them expensive.
E.g., see the first comment on this video: https://www.youtube.com/watch?v=m8TSiKHZbC8
> I work in this industry and yes these things are seriously expensive but also the cost isn't necessarily due to the hardware being expensive. The cost comes from testing and verification. Most integrators and launch providers want detailed information concerning vibration testing, material certifications for outgassing, vacuum testing and burn in. A lot of the players in the sat industry can't really afford to mess this up so they want to make sure the one shot they do have works. All of this additional engineering and testing costs are what kills the affordability. Even if you can get away with doing this all yourself, either academically or otherwise, no launch provider is going to let you on a ride share without this work, which requires specific testing hardware and a lot of man hours... which coincidentally costs a lot of money.
The launch provider usually doesn't care about radiation tests. For CubeSats they mostly only want to see vibration test reports.
Now, you and your user(s) will want to make sure that the satellite will work for a certain time while in orbit. So you throw all the functional and environmental tests that you can reasonably perform at it. And indeed, that's where you spend a lot of money.
I guess the launch provider doesn't care whether your satellite will actually work and survive in orbit. They just don't want it to break into pieces during launch and damage the rest of the payload. So they most likely just want vibration tests.
If you’re curious about the testing procedure here is a paper one open source project published about it. It’s by no means a comprehensive paper on testing but it gives a general idea. https://roboticexplorationlab.org/papers/PyCubed-SmallSat.pd...
Thanks!
https://dragonflyaerospace.com/products/ Here is an example of some CubeSat cameras to give you an idea of resolution.
https://www.groundstation.space/esa-funds-12-new-experiment-...
Until rockets get a lot cheaper, (come on Starship, deliver on your promise) to get a result that is commercially viable from such a timeshare option, you need to tailor your payload to deliver an outcome that can be actually desired. Everything is a trade off, and until the satellites get 5-10x cheaper to launch again, you're under very tight constraints and you truly have to trade off every other aspect (wavelength, sensor type, resolution, power level, communication budget, mass budget, geographic spread/location, orbital height) to get one good specific outcome in a 10x10x10cm form factor. Yes, you can fit mobile phone electronics in these things. But they are usually 200km+ away from what they need to measure. Until consumer off the shelf electronics can give you the sensor readings you need from an entire country distance away, the requirements is still going to need an act of true cutting edge engineering if your goal is to operate for-profit.
This is not impossible mind you, the industry will continue to mature. But it's a world of the future, not a world of the present.
Then there's also some other companies who make the satellite bus and other parts for CubeSats like GOMspace [3] and NanoAvionics [4] (it looks like they have started doing launch and mission ops as well).
[1] https://www.orbitalsystems.de/
There are several companies that sell partially built kits with aluminum chassis, PV cells and battery/charge system.
Carbon fibre is price competitive with aluminium.
Or so I thought, I just tried to Google the comparison per KG and it's completely spammed by alibaba and miscellaneous SEO.
Good luck, have fun with that. Would appreciate any industry in insider POV.
For a 1/32 thickness 12" x 12" sheet of carbon fiber, it is 35 dollars. This is actually this company's cheapest carbon fiber sheet too at that size. I have seen other companies charge more iirc. https://dragonplate.com/EconomyPlate-Solid-Carbon-Fiber-Shee...
Same sheet size / thickness for aluminum is 16 dollars (although I saw a shadier website selling for 12 dollars). https://www.mcmaster.com/aluminum-sheets/aluminum/multipurpo...
Now for cubesat grade stuff you might want something better than what I linked, but still its a good illustration of the price difference. That is over half the price. I think the prices are maybe closer than in the past, but there is still a significant difference.
Either way the raw material price is going to be dwarfed by the labour cost building the enclosure, which are also immaterial in your $50-100k budget.
1) CubeSat spec rules. The rules guiding CubeSats technically only allow aluminum. "3.2.15 Aluminum 7075, 6061, 5005, and/or 5052 will be used for both the main CubeSat structure and the rails." You can get a waiver, but it makes more sense to just keep to the spec for practical reasons. The CubeSat spec doesn't matter as much to private companies I think, but it does matter if you are a non profit or student team trying to get a launch with NASA.
2) Ease of use. This is the biggest reason (besides the CubeSat spec) most teams use aluminum. Aluminum is just so easy to build with compared to say carbon fiber. You can easily bend and drill aluminum to make the shapes you want for cheap. Carbon fiber is just difficult to work with.
3) Temperature resistance. Carbon fiber doesn't handle extreme temps as well. Outer space is extremely cold and in some cases it can cause carbon fiber to weaken. Meanwhile, titanium is a horrible choice because of its high temperature resistance. NASA explicitly tells people to not use it because Titanium has such a high melting point it can survive re-entry to Earth and accidentally hurt someone or destroy property.
4) Air trapping. Sometimes air can get trapped in composites like Carbon Fiber. This can result in it trying to escape into space and damaging the CubeSat. It's a major risk factor and one of the big reasons to avoid carbon fiber unless it's made in a specific way to ensure that doesn't happen. Unfortunately, it is hard to find carbon fiber that meets those standards.
5) Cost. For a 1/32 thickness 12" x 12" sheet of carbon fiber, it is 35 dollars. Same sheet size / thickness for aluminum is 16 dollars. That is over half the price. However, CubeSats are small (10 cm x 10 cm x 10cm in some cases) so material cost isn't as big of a deal as you might think. The bigger concern is the added weight might increase your launch cost. However, in practice the weight savings are negligible at the smaller CubeSat sizes. I should also note that the aluminum is mostly for the frame / chassis and that doesn't consume that much material. NASA charges nothing for their student / non profit launches so weight doesn't matter there as long are you aren't over the limit. For private launches, they usually round off the weight anyhow. Sometimes to the nearest whole KG, other times to the first decimal place. Either way, you probably aren't too concerned about weight due to the limited material used. I know for ours using Carbon Fiber wouldn't actually save on launch costs due to the rounding. If we were near the border or were doing a bigger sized CubeSat, then sure it might save us, but there are other things we can do first to save weight before switching materials. I think if we were building a very big CubeSat then yeah we might become concerned over the weight costing us extra. However, weight isn't the biggest factor for us simply because of the other reasons. Even if we wanted to, we couldn't use Carbon Fiber due to the air trapping and temperature issues.
Overall, the benefits of a lighter weight material like carbon fiber just isn't worth the difficulties that come with working with it. As a result, the standard is to use aluminum because it's cheap, works well, and is easy to use.
Edit: I said a 1U sat was around the size of a Rubik's cube before. However, I underestimated how small Rubik's cubes are. A Rubik's cube is 5.6cm on each size vs 10cm for the 1U CubeSat.
Speaking of the payload, that will greatly impact the build cost. I imagine you could put together the Cubesat equivalent of Sputnik for like $100, then another $200 or so for the FCC paperwork. If you want to send up interesting sensors, build something more durable/long lasting, have any sort of propulsion or decorating capabilities, etc the cost will start to approach or exceed what you're paying for the launch.
As far as launch prices, I think the 50k figure given is accurate, but only through companies that resell / broker space launches. Getting your own launch outside of a reseller / broker would cost more. For instance, if you buy from SpaceX's rideshare program directly it can cost 1.2 million. This is because SpaceX's base pricing starts at a 200kg payload. Anything that weighs less is still charged at 1.2 million. However, if you go through a third party that resells the launches then it can be 50k or lower. I know I have seen one as low as 20k for a 1U launch. The main reason why its cheaper is a combination of economy of scale (launching lots of cubesats at once) and/or VC funding. The best launch prices in general tend to come from startups who are heavily subsidizing the launches with VC money.
Also, if anyone is curious about cubesats or our work in general feel free to AMA.