KSP Community CubeSat

[CaptainArchmage]

Too late this year, but maybe next year?

http://www.smallsat.org/technical-program/workshop

I think Mars One is taking some suggestions for experiments for a probe mission to Mars in 2018-19, they might be interested, particularly as this cubesat seems to have the most votes for “Phobosâ€Â. We’d need to get that on sooner, not later.

As to propulsion: If we run a kickstarter, we can put that one up for a vote to those who contributed, as to what they’d want to see tested. I’d suggest two methods for propulsion, one to be tested (after successful ground testing, if possible, electrotether, Q-thruster), another that is already reasonably qualified.

Edited August 2, 2014 by CaptainArchmage

[Nicholander]

CaptainArchmage, we are going to do a KickStarter, but since I THINK we're about done on the super basic plan for the first mission, we should probably start to move towards starting our KickStarter, and we should start doing some technical stuff, and start actually designing this thing. (Oh, and a name would be great too!)

Though I don't know if I just jumped the gun WAY too early or something, but I think for the base goal, it should have no propulsion system. Pressurized area with some plants is what where doing, not testing fancy new propulsion systems.

EDIT: What do you think, K^2?

Edited August 3, 2014 by Nicholander

[Rakaydos]

CaptainArchmage, we are going to do a KickStarter, but since I THINK we're about done on the super basic plan for the first mission, we should probably start to move towards starting our KickStarter, and we should start doing some technical stuff, and start actually designing this thing. (Oh, and a name would be great too!)

Though I don't know if I just jumped the gun WAY too early or something, but I think for the base goal, it should have no propulsion system. Pressurized area with some plants is what where doing, not testing fancy new propulsion systems.

Indeed. Mission 1 is a credibility mission. Mission 2 is where we start propulsion tests.

[CaptainArchmage]

Indeed. Mission 1 is a credibility mission. Mission 2 is where we start propulsion tests.

If this is not just going to be a once-off mission, then I think that will be acceptable. We can then drop propulsion and maybe go for reaction wheel stabilisation? Here’s an example:

https://www.youtube.com/watch?v=9PiAdesZe5I

[K^2]

Though I don't know if I just jumped the gun WAY too early or something, but I think for the base goal, it should have no propulsion system. Pressurized area with some plants is what where doing, not testing fancy new propulsion systems.

EDIT: What do you think, K^2?

I tend to agree, but I really think we should talk to some bio people. Because at this point, we still don't know what we can actually do, and what type of experiment wouldn't be a total waste of time.

I like propulsion ideas because it's something I can understand, and where I can gauge feasibility fairly well. Unfortunately, so far, the safe, doable experiments are boring, and interesting experiments, like teather, are very complex mechanically, meaning that it's very unlikely that we'll be able to pull them off with the first run.

That's the main reason I lean towards bio experiment. But I'm still looking at propulsion options.

In any case, I think next stage should be simulation. I've realized that I'm not entirely sure what the requirements for various missions are going to be, so I'm not sure how to properly budget solar panels, etc. This is the sort of thing that can be resolved with simulation. I'll write a simple orbital elements integrator that assumes reference ellipsoid for Earth gravity and supports things like magneto-torque simulators. I can make it work with off-the-shelf 8051 emulators, so that software can be tested on the same platform.

Edit: I'll set up a GitHub repo for it as soon as I have some basics down. I'll definitely want someone else to look over the mathy parts of the code to make sure I didn't leave anything out.

[Nicholander]

Exactly, sim time! Though, do you know any (Preferably free) spacecraft mission simulators, there's definitely some from NASA.

EDIT: Is it possible to put up another poll, for example, I think it's about time that we give the KSP Community CubeSat a name, or do you think it's too early K^2? Here's some names:

(Also, you can put the -1 in front of all of these, which we should do since if we do a 2nd mission, we should do that. We probably will do a second mission, for example, ArduSat managed to pump out THREE CubeSats! (ArduSat-1, ArduSat-X, and ArduSat-2))

KerbSat

KSat

Kerbin

Kerbal

Harvester

HarveSat

CommuniSat

Squad

SqaudSat

KSPSat

Only ten because thay's the max you can put in polls. Though really, we should do KerbSat. It's short and has the word "Kerb" in it, and "Sat". Though that's just IMO.

Edited August 4, 2014 by Nicholander

[K^2]

Exactly, sim time! Though, do you know any (Preferably free) spacecraft mission simulators, there's definitely some from NASA.

For LEO, you don't really need NASA-grade precision, and I'd be more comfortable working with my own code. It's not really all that complicated, either. The equations of motion for the orbital elements with reference ellipsoid are known. So are the reference ellipsoid parameters for Earth, and it's going to be easy to add all of the other relevant forces as well. Just leaves integration, which I can do using an implicit method and a short enough time step to be almost perfect. Shouldn't be worse than what they used during cold war for ICBMs, and I call that good enough.

I can check my results against NASA tools and/or orbital elements of a satellite that's already up there.

[Rakaydos]

We can probably get a poll on the next thread- the one with the fixed OP that the mods have offered to sticky.

[Nicholander]

K^2, okay, you're right. But, are there any simulators, for things like vibrations during launch?

Rakaydos: Yes, that's certainly true. Though, K^2, when do you think you'll be finished making your simulator, and can make the 2nd thread. (Well, 3rd if you count the PocketSpacecraft thread which evolved into this)

[K^2]

K^2, okay, you're right. But, are there any simulators, for things like vibrations during launch?

No idea. And I'm sure that it's something that's going to be very different from vehicle to vehicle. I think the best we can do is get maximum acceleration due to vibration from the launch providers, and make sure the cube can survive that. As well as making sure there aren't any nasty resonances. The later would have to be simply tested for.

And yeah, I can get at least some base results quickly and start the thread with some numbers, etc.

[VirtualCLD]

Is there a separate thread regarding the first mission and list of areas where you may need some help? I couldn't find it in the Science Labs section.

[Nicholander]

There is no thread like that, the only other one related to this is discussing the Phobos lander mission.

[Nicholander]

No idea. And I'm sure that it's something that's going to be very different from vehicle to vehicle. I think the best we can do is get maximum acceleration due to vibration from the launch providers, and make sure the cube can survive that. As well as making sure there aren't any nasty resonances. The later would have to be simply tested for.

And yeah, I can get at least some base results quickly and start the thread with some numbers, etc.

Sorry a little late reply, but I agree with you on that. Also, along with simulations of things like electrodynamic tethers and magneto-torques, should we also start engineering and designing the CubeSat? Though, we could just push for later until we are done with the simulations.

[K^2]

We need simulation as a design tool. If you have a full RCS package, you can design control software around any CoM and moment of inertia tensor you end up with. But if you want to rely on magnetic torque, these are very important factors. I can tell you right away that orientation of principal axes will be critical. But I couldn't tell you without simulation how well that will play with shifting center of pressure on solar panels. Torque is one thing, but if you get an unexpected tumble, it could be really bad.

So I'd hold off on actual physical layout. We should definitely be talking about what components are actually needed.

So far, I have penned down main board with CPU, additional memory, GPS chip, and amps/drivers for any sensor/actuators; 6 square coils, one for each side, to provide magnetic torque; two cameras, one forward looking, one for the experiment; transceiver, probably an S-band; solar panels and a small battery; and a bunch of sensors. We can probably use off-the-shelf thermistors for board/frame temperature, some accelerometers to get rough values on rotation, magnetometers for rough orientation, and maybe some light sensors for sun/horizon detection etc. And, of course, depending on experiment, there could be a whole host of additional sensors. Precise temperature, pressure, humidity, oxygen, CO2, etc. There is a lot of room for improvement in each category, however. And that's going to be the hard part of designing things.

If you can think of anything I'm missing, let me know. But this should do for basic operations. The design will mostly include figuring out which of the above will be on the main board, and which we will wire, putting together a frame to hold it all together, and lots of testing for just about everything. It'd be nice to try and build a frame in a comparatively inexpensive way, because I'd like to drop a few mockups from different height and record damage vs acceleration experienced on impact by accelerometers. (Accelerometers and off-the-shelf CPU/MPU to do the readings are cheap enough to sacrifice.)

I have been looking at some 3D printers, but I still haven't looked up how reliable 3D printed plastics would be in space. On the other hand, it's just the thing for mockups and rapid prototyping. So hopefully, by winter, we'll have that option for testing things.

Oh, and you've mentioned organizational aspects at some point. I'm looking into ways of getting everything more organized.

[christok]

I may be wrong, but I suspect we would do best if we start with a list of things to research in the literature, and people who will do them. I'd also like to see more than one person per item. Knowing who has practical experience in these would help.

This list would include:

- A comparison of successful and failed cubesat missions. One component manufacturer's website I checked out claimed a 50% failure rate for university cubesats, not counting launch failure. We need to do better, and understanding why they fail is the only way. Correspondence with some of the creators would be a good idea and should be documented.

- Any and all available literature on partial-gravity biology, if we indeed decide to go that route. We also need to read up on Earth-normal botany and plants in microgravity. The latter two are slightly less important, as our experiment would not be quite as result-driven but rather demonstrate a method that has not been tried.

- We need to start looking at attitude control. K^2, I know you're looking into this and seem to have some electronics & software experience. We need to get this right because the design we have been discussing implies it. It will also be critical for future missions, if we get that far.

- Legal matters. ITAR probably doesn't apply to this project, but we need to do everything in a clear and organised manner so that we don't have problems. Especially true considering the international nature of the community.

- Materials. I know that teflon and anodised aluminium are both used in spacecraft because they resist outgassing and cold-welding. For the components we wish to build, which materials are flight-tested, and which are out of the question? Will we need to test any ourselves? Spacecraft electronics are sometimes given a coating to protect them against outgassing. There are some problems associated with this (especially w.r.t. fixing problems discovered during testing). Will it be a good idea in our case?

- Thermal design. Most cubesats tumble freely, which helps to control the temperature. As ours will point one side to the sun, and as cubesats have high surface:volume ratios, we need to make sure that we don't cook or freeze the experiment or critical components.

- Budgeting. We should try to gather information from the AMSAT/cubesat communities as well as consider what can be learned from traditional spaceflight.

- Crowdfunding. We should study the available literature on failed/successful crowdfunding efforts so that we know if, for example, a silly name would benefit or undermine a scientific project on Kickstarter et al. Giving out goodies such as mission patches seems to be required. But how much, and what? How many backer levels should there be for a Kickstarter project? How far apart should they be, monetarily? What percentage of the pledge should the rewards cost? How often should updates be posted? How big should the stretch goals be? How early or late in the funding process should they be added? Would it be an advantage to loudly associate the project with KSP players, or would it be better to put it in a footnote? (I.e., would we be taken more seriously if we emphasise ourselves as a community of spaceflight enthusiasts who happen to like KSP, or as a community of KSP players who want to reach out and teach/learn aerospace engineering in a practical manner as the game has done for many? Will something like "JebSat" lure backers, or scare them off?) If necessary, we should do our own comparative studies. This could make or break the project, especially if we're planning more missions.

- Power.

Who has a ham licence or intends to get one? It's not critical right now but we will need to set up ground stations.

Doing some sort of educational outreach (even if it's just talking to schoolkids afterwards and showing off pictures of the satellite) would be a nice bonus. Would some people on the project be interested in that? We can also do education directly, by allowing kids on the forums to assist with some easier aspects of the design process and sharing information as the project progresses. This would however take a little extra work. Would you be interested?

Not a literature study, but we should start brainstorming ideas for artwork, names and related things. I recommend that we designate different levels of seriousness. When we see everything together, and when we have more data on the crowdfunding requirements, we would be better able to judge how serious we should sound and pick the best in each category.

Here's what I have in mind. Let's say we divide the names into completely silly, in-joke and completely serious.

- MysteryGooSat is silly.

- Making up some backronym to fit an appropriate KSP part, such as ASAS or SC-9001 Jr, would be an in-joke not obvious to the casual observer.

- PEGES (Partial Earth-Gravity Experiment Satellite) woudl be a serious example.

I can probably think of some more things.

[Nicholander]

K^2, I don't have a RCS package (Actually never heard of that type of thing before). So I understand, engineering and designing LATER, first simulations. Though on the hardware you mentioned, that all has to fit in a 0.5U area, because the other half will be taken up by the pressurized area. I see how that is possible (They sell 0.5U on many CubeSat websites), but since we will also need systems controlling the pressurized area, which will certainly be a tight squeeze. So we will probably haft to use "Home-made" components, which is fine. Also, maybe you should make a reasonably good visualization of our CubeSat (Pressurized area with plants) and put it on the first post on the new thread you're going to make after you're done with the sim you're creating.

christok, I say we name it KerbSat (But there still would be a poll here on the KSP forums), and we'd probably hire a 3D graphic artist to make a visualization similar to the ones other crowd-funded CubeSats have.

[VirtualCLD]

Who has a ham licence or intends to get one? It's not critical right now but we will need to set up ground stations.

I have a US HAM Extra license, but I no longer have access to satellite tracking equipment (I used to at my grad school).

[TheAwer]

This sounds fascinating!

I've only read to the 11th page, but if you guys are still thinking of landing on Pheobes, why not use solar panels extending beyond the engine as landing legs? You would lose the bottom side, but the top would still work (assuming they are two sided).

I have really no idea what I'm talking about, but I wanted to share this before I forgot it.

[Nicholander]

If we eventually go to Phobos, there will be no landing legs. When it's VERY close to the surface, it will slow down it's velocity to almost zero, and then "Fall over" onto it's side, probably with a "Cushion" to prevent any Magda of the equipment. This prevents the need for landing legs.

[L3GO]

What we need is maybe to make a simulation video trailer thingy.... I think we should use KSP for any Videos we make for it so if this goes public and stuff. I would be willing to help out with that stuff.

[Nicholander]

As this thread is stickied, I think it's already pretty popular within the KSP community. And, we probably are going to make a video with KSP (Probably with RSS), though it should be made on a computer which is WAY better then mine.

[L3GO]

I would also think that a texture pack would also need to be used unless we just keep it stock textures.

[K^2]

What we need is maybe to make a simulation video trailer thingy.... I think we should use KSP for any Videos we make for it so if this goes public and stuff. I would be willing to help out with that stuff.

Yeah, I think it's been suggested. It'd probably go over better with Solar System mod, so that it shows an actual Earth bellow. But other than that, for publicity stuff, I think it'd be great to get it done in KSP. We need to have some basic design ready for someone to model the sat for the game, though.

It needs to be crystal clear that KSP isn't what we're using for simulation, though.

[Nicholander]

Certainly, someone should make a "Mini-mod" which has our CubeSat, and does this sort-of count as a basic design?:

I didn't include any antennas because we don't know which antenna(s) we will get, and everyone looks different.

[Rakaydos]

I wonder if you could simply use "stretchytanks" or somethig similar, to scale components DOWN to cubesat size?