KSP Community CubeSat

[K^2]

Simplest way would be to have a USB MCU on board that talks to the phone. Though, to be honestly, the only advantage of the phonesat is working with a camera. For everything else, it'd be better to just have a better MCU that controls everything. Phone GPS would probably be useless in orbit, since they are usually locked to within certain velocity ranges. And accelerometers are cheap either way.

[Nicholander]

The problem is that spacegrade computer are at 2.5 k $. That's quite pricy.

IF we can get a ride to LEO for less than 10 k $ and IF we can have a ground station for 5k$ dollar or less, it would be possible.

20k to 25k $ is reasonnable for a quickstarter.

So. Does someone know if we can get either of them or both ?

The least I've seen a CubeSat KickStarted for is 50k. So we can do at least double then 20k to 25k for our KickStarter.

[Error404brain]

If, as said by someone, space grade stuff is overpriced, we should get a space grade cpu. Because he would be able to withstand way easily the 6 month or so mission for to test the inflatable module. Apparently, heat isn't a problem since space grade cpu just need to be heated (no chiller). So, a radiation geiger (100$), a thermometer (20$) and a pression tester (50$). With that we need just a camera (100$) and an heater (100$).

For the ground station, anyone got info ?

And stop thinking about living stuff. No one accept it if it's not with a deorbiting system.

[Error404brain]

The least I've seen a CubeSat KickStarted for is 50k. So we can do at least double then 20k to 25k for our KickStarter.

If the launch is 30k $ and the ground station 100k $ We would be better with an interplanetary mission. It wouldn't happen.

[K^2]

I'm basically going to see if I can build an S-band ground station and have it communicate with something already in orbit. (A number of cubesat projects have open comms protocols.) Almost all of the components are going to be salvage, so it's dirt cheap, but it might take a bit of time putting everything together and writing control software.

S-band is a good choice if we end up going with a phonesat, but there are a number of high quality s-band transceiver options as well. So it's a pretty safe choice.

We really should try and see if there is a good 1U free LEO ride option we can get in on, because that's going to be the most expensive part of the basic mission. Everything else can be done on a modest budget.

[AngelLestat]

Tens of thousands? As AngelLestat said, it is actually quite cheap. Just an aluminum wire and a weight on the other end.

I dont have any idea of the price of that thin and double aluminum wire. But in any case, if our misssion it would be short, maybe we can risk us with a single thin aluminum wire. That is something that we can get in any place. I would do my research on that.

No matter what we build it can't have anything on the outside. It has to fit inside the little deployment bay on the spacecraft. They bay is built for cubes exactly 10x10x10cm. I wasn't aware that the tether would need a weight at the end as well. It probably wouldn't need to be as heavy as the mars direct type centrifuge it still has a penalty on what equipment we can bring. The tether type of mission needs a 2U cubesat.

The weight that it needs to passive deploy the tether is similar in size and weight to a smartphone battery.

Simplest way would be to have a USB MCU on board that talks to the phone. Though, to be honestly, the only advantage of the phonesat is working with a camera. For everything else, it'd be better to just have a better MCU that controls everything. Phone GPS would probably be useless in orbit, since they are usually locked to within certain velocity ranges. And accelerometers are cheap either way.

In case you want a long time mission, maybe the smartphone would not be a good choice. But the cost saving using a smartphone are not only those that you mention.

You dont need to develope the OS for that or software to control all the basic things (sensors, transmission, manuver software, etc) if you use a smartphone. You can use the already develope softwares for those smartphones.

You can also control how much resolution your cameras would use, what phone devices needs to be off or on.. You have tons of software already develop for smartphones that would help you to process data before send it, we can save a lot of energy in transmission sending only the most relevant data.

Then the fact that you had already all include and connect it to one device, is a huge benefic. The 2 cameras are very usefull, all sensors are very usefull (some only in the launch, but that is valueable data too)

Smartphones already had software to consume the minimun energy with the processor. You get all in one thing, memory, battery, bluetooth, etc. And what can be more cheap than a smartphone?

That is why nasa or other big agencies are doing the same in their cubesats, to show people how to save money.

You want something with propulsion (lets forget about tether for now), how you would keep stabilize the cubesats in the propulssion phase?

[Sky_walker]

FYI: Radiation doesn't work on the electronics in a way some of you think (or at least: I think that you think... )

Read this.

Basically: If your electronics are not rad-hard then software that runs on them might crash in a first minute it gets into the thermosphere or it might run fine for weeks. It might be permanently damaged in a few minutes, or it might take many orbits till you won't be able to reboot it any more.

It's more.... like a random numbers generator than a progress bar that has this magical "won't work anymore" point, only you don't know where.

That's why satellites and probes have multiple computers (usually: 3 with 2 running identical operations), even if they are rad-hard. It's a lottery where the best thing you can do is decreasing chances for a failure.

Edited July 17, 2014 by Sky_walker

[cpast]

We don't need to get a 1U at all. 0.5U exist.

Source? The only sizes the spec defines are 1U, 1.5U, 2U, 3U, 3U+. There's another spec by different people for future 6U, 12U, and 27U forms, which are multiple units wide. No reference to a 0.5U.

[Sky_walker]

Source? The only sizes the spec defines are 1U, 1.5U, 2U, 3U, 3U+. There's another spec by different people for future 6U, 12U, and 27U forms, which are multiple units wide. No reference to a 0.5U.

https://www.google.com/search?q=cubesat+0.5+U

[cpast]

https://www.google.com/search?q=cubesat+0.5+U

Ah, so it's not in spec, but people have figured it out from spec and a couple have been launched. However, since it's not spec, you might have a harder time with launch opportunities (you might not).

EDIT: Scratch that. I see a reference to two launched, AeroCube 6A and 6B, and they were launched together (as a 1U) and separated in orbit. We're back to "find evidence of launch opportunities for non-spec 0.5U".

Edited July 17, 2014 by cpast

[K^2]

Basically: If your electronics are not rad-hard then software that runs on them might crash in a first minute it gets into the thermosphere or it might run fine for weeks. It might be permanently damaged in a few minutes, or it might take many orbits till you won't be able to reboot it any more.

Part of why I don't like idea of a phonesat. Even if it can be rigged to auto-reboot on crashes, it's going to take time. For an MCU, custom code can be written to do some error-checking/correction on the fly and reboot automatically and quickly on any critical crash.

But it's still going to be just luck whether the thing last an hour or a month from there on.

I would very much like to have an option to spend a few $k on a good rad-hard CPU, though. Compared to other costs, it's fairly reasonable.

[AngelLestat]

FYI: Radiation doesn't work on the electronics in a way some of you think (or at least: I think that you think... )

Read this.

Basically: If your electronics are not rad-hard then software that runs on them might crash in a first minute it gets into the thermosphere or it might run fine for weeks. It might be permanently damaged in a few minutes, or it might take many orbits till you won't be able to reboot it any more.

It's more.... like a random numbers generator than a progress bar that has this magical "won't work anymore" point, only you don't know where.

That's why satellites and probes have multiple computers (usually: 3 with 2 running identical operations), even if they are rad-hard. It's a lottery where the best thing you can do is decreasing chances for a failure.

That answer is for me?

So what are you saying? that we need to have 2 cpu in a cubesats the same as one billion satellite?

Or that CPU in sale for cubesats has an special electronic or shield to survive the space?

They might be better prepared to deal with those conditions, but you can shield a smartphone too.

If we reduce the lifespan expectations of our mission, then all became more easy and cheap to achieve.

The use of smartphones is not my idea, as I said, many agencies or groups are starting to use them for their missions.

[dharak1]

There are a few things we don't want to cheap out on like batteries solar panels and cpu.

[Aethon]

Of course this is way off in the future, but if K^2 can build something that cheap, we (K^2 says we? Whaddaya got a turd in your pocket??) may as well build two and sell one at a slight profit to some guys a little further along than we are now. I can hear sky_, howling with laughter.

As to funding : At the point we are now, I'm fully willing to transfer $100 to K^2 tomorrow. Not that I'm going to mind you. If this project becomes less.. theoretical I can come up with much more over time through some creative community involvement ideas I have.

It'd be nice if we had one place (computer nerd powers activate)- where those of us who have money can give sort of a 'funds' ammt. pledge. A page somewhere (so we're not clogging up the forum) we can all edit like:

Aethon....... $100

K^2............$100

etc.

Certainly nothing set in stone,( don't get excited and pledge what you ain't got ) but to give the rest of you some idea where we are financially.

Nick sure likes to type, can u set something like that up mate?

Also to Greg : Figure out a way to attach ESTES MODEL ROCKET motors to space debris, and fire them retrograde to deorbit stuff. We'll all be rich and very Kerbal!

Baby steps.

Sorry about the brevity but gotta work!

Edited July 17, 2014 by Aethon

[Sky_walker]

So what are you saying? that we need to have 2 cpu in a cubesats the same as one billion satellite?

Nope. I'm trying to point out that degradation is random - it's not a progress. You can say that, for example, after a year chances of permanent damage to the CPU will exceed 50%, but just as well your sat phone might get broken while still on an upper stage of the rocket.

Rad-Hard computers are worth their price. That's why majority of cube sats run on them instead of things like Raspberry Pi, Arduino or smartphones. Yes, the demand for PhoneSats is going up, but: from zero you can only go up .

And if you still think it's not a problem - read this and the remind yourself that people here wanted to transfer video down to the ground, not just pathetically low-res pictures. And that's the project supported by NASA, not some random people from a random forum.

Edited July 17, 2014 by Sky_walker

[B787_300]

why not a google excel page...

[K^2]

Or that CPU in sale for cubesats has an special electronic or shield to survive the space?

They might be better prepared to deal with those conditions, but you can shield a smartphone too.

Logic and manufacturing techniques are different. Rad-hard CPUs are typically built on different substrate with more redundant elements and some ways of catching errors.

Shielding just isn't going to cut it. Sufficient shielding would simply weigh too much for a cubesat.

[Aethon]

Do it!

Put my John Hancock at the top! Ole King George won't need to put his specs. on to read my name.

Plus, you know.... alphabetically...

Edited July 17, 2014 by Aethon

[AngelLestat]

There are a few things we don't want to cheap out on like batteries solar panels and cpu.

Why not? many are doing it.

http://www.csmonitor.com/Science/2013/1120/Satellites-controlled-by-a-smart-phone-Tiny-CubeSats-reach-space

http://news.techeye.net/science/nasa-puts-three-more-smartphones-in-orbit

http://www.engadget.com/2013/02/26/google-nexus-one-launched-into-space-cubesat-phonesat-strand-1/

http://sen.com/phillip-keane/5-new-cubesats-successfully-launched-on-falcon-9

http://www.spacenews.com/article/smartphone-powered-cubesats-fly-antares-maiden-launch

Tell me the difference between a smartphone battery and a cubesat battery.

Nope. I'm trying to point out that degradation is random - it's not a progress. You can say that, for example, after a year chances of permanent damage to the CPU will exceed 50%, but just as well your sat phone might get broken while still on an upper stage of the rocket.

What are the chance difference to get a fail in the first day using a smartphone vs a cubesat CPU?

smartphones electronics may had 0,01% of chance to fail vs a 0,0001% from a standard cubesat CPU?

What really matters is how big your lifespan expectation are. If we keep our expectation low (short mission). Then we can save a lot of money.

Smarphones were not used before just because the smartphone boom was in these last 3 years.

PD: I forget a extra use for smartphones... They had GPS!! In low orbit GPS work as well as in surface!

Edited July 17, 2014 by AngelLestat

[Kryten]

The GPS on a phone will stop working if it detects altitude and/or movement speeds outside of a certain range.

[B787_300]

Link to get a rough idea how much money we could have tomorrow if we went through with the idea. DO NOT TOUCH THE TOTAL AREA, it automatically updates. Also THIS IS UNOFFICIAL AND NOT BINDING , but PLEASE ONLY SAY AN AMOUNT IF YOU PLAN ON DONATING

https://docs.google.com/spreadsheets/d/1noDHJlfbIF57V6_0_iIlB_kpeuHq4kLMPZBNyI1NXr8/edit?usp=sharing

[AngelLestat]

The GPS on a phone will stop working if it detects altitude and/or movement speeds outside of a certain range.

Why it would stop working?

In any case that the gps software is not prepared to deal with those numbers, you just need to mod the software..

[PlonioFludrasco]

GPS sensors are "locked": they are disposed to stop working if the device is moving too fast or too high. That in case someone would like to build a guided missle in his garage (or worse, an enemy country). Remember that GPS is operated by USAF, and they don't like it(with reason).

But there are also unlocked GPS devices, that obviously need an authorization or something similar.

Edited July 17, 2014 by PlonioFludrasco

[cpast]

Why it would stop working?

In any case that the gps software is not prepared to deal with those numbers, you just need to mod the software..

It stops working to prevent its use as a guidance system for ballistic missiles. Under US law, any GPS system without those limits is subject to arms control restrictions. It may or may not be legal in the US to remove those limits, and it is *not* likely to be legal to send it to any other country without permission from the US government.

[AngelLestat]

those answer are wrong.

GPS home system, low time ago, they had a restriction of 10 m on accuracy, that restriction now is out.

Thats it!

There is no more lock.

http://www.nasa.gov/centers/ames/engineering/projects/phonesat2.html#.U8f0kvmSzwA