KSP Community CubeSat

[dharak1]

My science teacher and his wife are biologists. I don't k ow how experienced he is but I'm sure he would be happy to help out. What kind of data would we even be able to collect without bringing samples back?

[K^2]

Hm. I think, amount of chlorophyll can be estimated by exposing plants to UV (while on the dark side, using UV LEDs) and measuring red/IR light intensity. An oxygen sensor is also not completely out of the question. And there is visual, of course, from the rear-facing camera.

I'll poke at some biologists as well, but it'd be nice to have someone from community.

[dharak1]

Are you sure all of this will fit in a .5u stack? Do we have any estimates on the weight of some components we could use?

[Nicholander]

Ah, so our basic mission we're doing a centrifuge and a "Life in a jar". Great! K^2, I think we should put some Java Moss and maybe some bacteria in the jar.

- - - Updated - - -

Are you sure all of this will fit in a .5u stack? Do we have any estimates on the weight of some components we could use?

I think we're putting it in a 1U, not a tiny 0.5U.

Edited July 18, 2014 by Nicholander
Removed stuff about centrifuge.

[dharak1]

I thought we were generating the artificial gravity simply by spinning up the cubesat to 30 rpm like k^2 said.

Edit: we are effectively using .5 u for electronics because the jar will take up half the sat.

[Nicholander]

*Facepalm* *Facepalm* *Infinite Facepalm* Forget what i said about the centrifuge. I didn't read it correctly. Sorry. *More facepalm*

[K^2]

Centrifuge won't cost anything, because the entire sat will spin. I'll just need to figure out how to make that happen with magnetotorquers without causing it to tumble. Most likely will be down to balancing all of the components very carefully.

And I honestly can't say yay or nay for any suggestions on flora or fauna. You can suggest cats, and I'll be all, "Yeah, that's awesome. They'll have to be tiny cats, though." If you ever need an example that proves that publication on cellular biophysics does not make one an expert on biology, feel free to point in my direction.

I will definitely at least talk to someone from bio about this, though.

Are you sure all of this will fit in a .5u stack? Do we have any estimates on the weight of some components we could use?

Sensors, lights, and anything else hardware related can go on the hardware side of the cube. There'll be some room there. Plus, it's easier to just stick everything onto a single printed circuit board. But yeah, it's part of the reason why I'm not sure about oxygen sensor. These things tend to be bulky. In cars, at any rate. I'll look into that.

So the .5U should be just the jar with the plants. I'd like to have glass jar, but that might be problematic. In which case, perhaps, acrylic? Or plexiglass? That will be like a an open gate for radiation and UV, however. Might be a bit much. On the other hand, figuring out what will and will not survive space rad is part of the experiment, I believe.

[dharak1]

That's fine. We need to decide on hardware now. We need things like high quality batteries and computers. Solar panels are important too.

Edit: I would go with acrylic. I've tried making plexiglass cases for stuff larger than .5u and it's pretty hard. I agree that testing rad effects on plants and bacteria would be part of the experiment.

Edited July 18, 2014 by dharak1

[K^2]

Well, batteries need to last for half an hour at the most. And in fact, it's not a tragedy if the thing resets due to bad batteries. Just means we wouldn't be able to test things on the dark side. So I wouldn't stress over it too much. If we have the budget for better batteries, something designed for space, we'll go for it. But controller and memory would come before that on my "must upgrade" list. Again, pending availability of the funds.

Base budget can be designed around an off-the-shelf MPU. Like I said, I'll look into some software error-correction options. Error-correcting memory is awesome, but it's pricey, and rarely includes anything more fancy than a parity bit. I can build an architecture with a co-processor whose sole job is managing memory in Z_p using polynomial error correction. But that will slow things way down if each read/write will have to go through a separate processor.

Anyways, can't go cheap on solar panels. Then first to upgrade are MPU/memory, then battery and sensors. Finally, cameras. I suspect rad-hard cameras to be very expensive. And then we can look into expanding experiment. Tethers, 2U, that sort of thing.

[dharak1]

Would a mission like this require deployable solar panels? They wouldn't offer much of an advantage over fixed ones unless our rotation was perpendicular to the sun so we could have as many as 3 panels gaining power at once.

Edited July 18, 2014 by dharak1

[Nicholander]

So we've got an objective, A centrifuge and (Hopefully, if the LV carriers allow it) biological matter. What else is there, so how expensive will our base goal be? 60k? 40k? 50k?

[K^2]

deplorable solar panels

Charging despicable batteries.

It might be a good idea to have them angle a little. But not, strictly speaking, a requirement.

So we've got an objective, A centrifuge and (Hopefully, if the LV carriers allow it) biological matter. What else is there, so how expensive will our base goal be? 60k? 40k? 50k?

I think it's about time to put together a "shopping list" and see. I'm still hoping to be under $10k for the base unit. But that doesn't include launch or ground support. I'll find out what requirements are from NASA for an ISS launch or similar, and see if there is any way this mission can qualify for a free ride.

So I'll get back to you with some numbers shortly.

[dharak1]

Haha I did that on my phone and while I used to be a strong advocate of its keyboards I much prefer my tabpro for long messages. It took me a bit too long to realize my mistake though. I hope we get a lunch from a p-pod on the ISS.

[Mr Shifty]

With ionizing radiation, the only thing that matters is center of mass energy. Not the type of particle that delivers it.

I'm just a rad worker, not a physicist, so correct me if I'm wrong here, but I've worked in radiation environments for more than 10 years and I get the standard radiation spiel for rad workers once or twice a year. Charge and mass are also important, which is why you can stop 7 MeV alpha particles with a couple cm of air, but 7 MeV gammas take several cm of lead. And though protons are charged and therefore are stopped relatively easily, they produce thermal neutrons through scattering in structural materials, which require not high density materials, but special materials with high neutron capture cross-sections: Boron-10, Cadmium-113, etc. (Most metals tend to be transparent to neutrons regardless of material density or neutron energy, which is why nuclear reactors use materials with relatively high total neutron cross section for neutron shielding: water, borated poly, etc.)

So no, I don't think magnetic shielding is viable.

On the other hand, LEO (if that's what we're still talking about) is well within the geomagnetosphere, which deflects almost all solar origin radiation and most galactic radiation as well (some really high energy stuff gets through.) Astronauts at the ISS don't, for instance, retreat to a radiation shelter during SPEs. I'm talking out my ass here, but I don't think radiation hardening is going to be a huge concern for electronics in LEO. And if we want to be careful, we just have to limit ourselves to older, slower electronics with larger gates. (For instance, newer high-density FPGAs don't survive too well in the high-rad area at work, but 20 year old DIP MCUs and CPLDs do fine.) The larger concern is going to be temperature and vacuum.

[Aethon]

sorry hit wrong button, be within a sec.

[christok]

My concern about using plants is that I'm not sure they'll survive the direct sunlight they need for photosynthesis. UV is pretty extreme up there and we may have to use an opaque container with artificial lighting. Or maybe not. But we'll have to research this so it doesn't lead to embarassing failures.

[dharak1]

That could be part of the test. We could see how long plants last up there or if they can survive at all.

[Aethon]

Ok, granted I've had a few toddies (drinks),

K fortunately for both of us, what I tried to post a minute ago is now lost to the cntrl c cntrl v thing. Above is the relevant bit that remains.

The gist is that I went to work today, excited about our Non binding funding page total ( 20 minutes after it was started ). Slaved away. Saw a former middle school principal at the grocery store- apologized for past infractions and found out how to get KSP edu in my local school, felt out my local (pub) citizenry on how they felt about contributing to such a thing as this, with no guarantee of ever hearing about our sat again- nearly gettin' in a fight ( pardon me but I'm fired up) with a little minded, small town, swingin' wiener, who had a hot girlfriend and didn't want to hear a darn thing outta my granted loud mouth, about space (how hot his girl was ) or nothin', and I come home to see that nobody here's ready to 'pretend' they're putting their money where their mouth is??

Guess I'll havta refund the $79 buck I collected from the good people in my town, willin' to take a small chance on a pipe dream. "Fortunately, I always keep my feathers numbered- for just, such, an emergency." - Foghorn leghorn.

I guess Packled hostage was right- It is broken...

Imma go into a 2 week .24 coma.

Wake me up when you're serious.

https://docs.google.com/spreadsheets/d/1noDHJlfbIF57V6_0_iIlB_kpeuHq4kLMPZBNyI1NXr8/edit#gid=0

Thanks to the 4 that stepped up. It was fun while it lasted!

Edited July 18, 2014 by Aethon

[Daddy Cecil]

Question is, why hasn't anyone made a CubeSat mod for KSP? Probably the model would be too small. Arguably, the Probodobodyne QBE could be considered a 6U sattelite.

OT before derail: Looks cool, but can't donate because no spare moni :<

[Nicholander]

I guess Packled hostage was right- It is broken...

Imma go into a 2 week .24 coma.

Wake me up when you're serious.

Thanks to the 4 that stepped up. It was fun while it lasted!

What do you mean? You're leaving this project like Packled Hostage?!? Or am I just terrible at understanding things.

[dharak1]

I think it may have been a tad bit too early to collect funds. Once we do a kickstarted I'll probably go around and explain the mission to the science teachers at my school. I'm sure they would be willing to donate and help fund the cubesat.

[Creature]

I've got a BSc in biotechnology and I'll be starting my master's thesis this fall. It's more biochemistry and diagnostics than biology but I'm happy to help with what I can just out of curiosity. A small scale bio experiment is relatively simple in theory but I have no clue how a launch provider would feel about it if you're not from a certified bio lab. In any case it should be something that deals with short term exposure to LEO conditions to justify the need for a cubesat.

[K^2]

The only advantage this could have over ISS and Earth experiments is low-G exposure. They've done microgravity on ISS, and hypergravity has been done on Earth. But it doesn't look like there have been any hypogravity experiments.

No guarantee that it'd be useful, but at least, it fills in the gaps in the data. We could probably run it with Moon's gravity and maybe even get it up to Mars to see how viable hydroponics on Lunar/Martian bases could be.

Radiation shouldn't be too bad in LEO, but at least one candidate species should be something that is particularly likely to do in strong UV.

With NASA, the most likely ride would be via ISS, which would give us a very good starting orbit with as much as half a year before it decays. But it's likely to be extra strict on biologicals. A routine sat ride would probably not care what you put up there, so long as it's not harmful to humans if it's accidentally released. With ISS, things would definitely need to be checked with NASA on case-by-case. The container will be sealed. Exterior can be sterilized. But they might still want demonstration of ability to have nothing in the jar other than what's on manifest. That probably means we'll need help from a university bio lab equipped to handle something like that. But that, in itself, isn't tricky to get assistance with. I'm sure there are plenty of unis that wouldn't mind giving students some exercise in whatever's the bio equivalent of clean room procedures.

What I mostly need to know from someone who's bio savvy, is what's the minimal diversity needed for a closed system to survive for up to half a year? What I need in there to get the ball rolling? And what temperature ranges should be maintained? Ideally the temperature range should be as high as possible. That will probably affect the choice of the species.

One more thing. Before we can get sat in orbit and establish the hypogravity environment, the container will undergo significant over-G followed by considerable length of free fall. I'm sure whatever's inside can weather it out, but mostly that's to point out that what we have inside can't rely on gravity or its lack for staying put. If jar isn't completely filled with water, that water will slosh about. So will any loose soil.

I suppose, a solution is to simply deal with the volume being completely filled with water, but that will both increase the mass of the sat, and will reduce impact of hypogravity. It'd be more interesting to see how plants can grow above "surface", I would imagine. But it might be possible to have something like a clear sponge to act as "soil" and have some algae or other organisms in that sponge.

Anyways, just some thoughts and technical limitations.

P.S. Bonus points if the plant or full ecosystem could actually be useful to a Lunar/Martian base. Naturally, growing crops is out simply because of available volume.

Edited July 18, 2014 by K^2

[PlonioFludrasco]

Here's all the documantation needed.

http://www.cubesat.org/index.php/documents/developers

I've also found somewhere some CAD models of the structure, I'll get a look to it.

[K^2]

That's a lot of paperwork. Noted and bookmarked. Thanks.