KSP Community CubeSat

[Sky_walker]

@Sky_walker:

Does streaming for 1 minute and then stop doing that still counts as livestreaming? No one says that you need to do 24/7 livestream, yes?

Again - streaming a video is extremely difficult without proper professional infrastructure.

Again, the communication system is an issue. But probably laser comm will solve that.

Laser comm? Seriously? You know that both: ESA and NASA still consider it an experimental tech and you want to use that in your a cube sat?

we can cheat and use omnidirectional antenna

It's not a cheat. It's how you do things in a cube sats.

Sails.

Warp drive.

Easier to use, quicker, and can be renamed to Karp Drive.

On a serious note: think about reliable technologies. Not stuff that didn't even go past the experimental stage in a real space agencies.

While I agree that live streamed video is probably impossible for the type of budget we'd be likely to be working with, there are off the shelf camera systems that stream still photos (of various resolutions and image file sizes) over serial. The cubesat's onboard processor could packetize that data and downlink it using a low bandwidth protocol. Sure, the devil is in the details but you can't dismiss downlinked images with the wave of a hand.

There are ready-made computers capable of handling images and then dedicated transceivers to transfer them. But it's not streaming. And just yesterday an idea was to save money and build that yourself from some commonly available parts instead of buying pre-made cubesat computers and transceivers for tens of thousands of euro (cause that's the rough cost of the equipment capable of transferring images).

If a project like this is going to ever have a hope of actually coming together, it is going to have to appeal to a large number of people. Photos from space updated regularly and posted on a website may be a necessary component of the project, just from a marketing perspective.

Well, this and: it has to have some chance of success. Sending a cube sat to fail (read: Phoebe mission) might get some money from few naive KSP forum members, but that's about it.

Edited July 16, 2014 by Sky_walker

[Error404brain]

For pointing that's quite easy. The camera can record a revolution around the earth, and so, using some maths, we can easily get the rotation of it and thus it's actual pointing.

[Error404brain]

"On a serious note: think about reliable technologies"

Kerbal space program.

KERBAL.

Anyway, CAT is using also an untested IIRC propulsor. Thus, your point is invalid.

And failure still mean datas.

[Nicholander]

All this talk about propulsion systems is good and all, but is it even possible to put one on a CubeSat cheaply? Well, it probably is, but it'd need to be something simple like a plain old RCS powerd engine. But, we should do something unique, And oir Kerbal/unique options are:

GTO

Debris de-orbit tech demo

Pulse propulsion

Ion propulsion system(Less unique then the others)

Solar sail

Live visual footage feed

I didn't put the Lunar or interplanetary ones because those are essentially impossible for our first mission.

[Aghanim]

Well, if you want to push streaming to its limit... do SSTV. Its technically still streaming, but its so slow.

And really? You are comparing an experimental real world propulsion tech with a theoretical research paper only drive

And yes, I do know that space laser communication is still in experimental stage. But free space optical communication is already in commercial stage. Again, let me reiterate. The mass penalty is small. A green 5mW pointer only weighs at 138g. More weight saving can be achieved by removing the pen and using bare diode, driving it with a driver and modulator circuit, using the cubesat body as heatsink . We could probably spare some payload space for this.

But... that 138g can be used for a more useful purpose! What? Actually, I don't know because the primary objective of this mission is not clear, yet

Edited July 16, 2014 by Aghanim

[PakledHostage]

There are ready-made computers capable of handling images and then dedicated transceivers to transfer them. But it's not streaming. And just yesterday an idea was to save money and build that yourself from some commonly available parts instead of buying pre-made cubesat computers and transceivers for tens of thousands of euro (cause that's the rough cost of the equipment capable of transferring images).

I am aware of the definition of streaming, thank you. And I am surprised to learn that the ~500 CAD pile of electronics and associated custom firmware on my desk at home that transmit still images over radio telemetry are worth tens of thousands of euros! Maybe I should try to sell them in Europe?

[Sky_walker]

For pointing that's quite easy. The camera can record a revolution around the earth, and so, using some maths, we can easily get the rotation of it and thus it's actual pointing.

No, it's not. You need precise control over thrusters, ability to send and advanced, multi-stage commands to the computer on a cube sat, reliably execute them... then there's a problem with your ability to transfer multiple images down to earth, preferably in a single comms window... though you don't even know how long these will last, yet along got any clue about data transfers you could possibly achieve.

One of the cheapest ways of orienting cube sat is by orienting yourself to the sun - then combining this data with time and your location on the orbit to find out where the ground is.

You see guys - that's the problem. You don't even know such a basic things. No idea why you waste time posting here instead of READING and LEARNING some BASICS.

I am aware of the definition of streaming, thank you. And I am surprised to learn that the ~500 CAD pile of electronics and associated custom firmware on my desk at home that are capable of transmitting still images over radio telemetry are worth tens of thousands of euros! Maybe I should try to sell them in Europe?

And exactly how far can you transfer this data?

---------------------------------------------------

And oir Kerbal/unique options are:

Reality check!

GTO

90% impossible to happen (10% shared with extreme luck and extremely expensive)

Debris de-orbit tech demo

Impossible.

Pulse propulsion

You'd need to elaborate what you mean by "pulse", but if it's what I think you mean, then: Impossible.

Ion propulsion system(Less unique then the others)

Very Expensive.

Solar sail

Impossible.

Live visual footage feed

Impossible.

I didn't put the Lunar or interplanetary ones because those are essentially impossible for our first mission.

Not only your first, but pretty much: every single one after that. Unless you get hired by one of the governmental space agencies.

Edited July 16, 2014 by Sky_walker

[R0cketC0der]

The mass penalty is small. A green 5mW pointer only weighs at 138g.

If we go with a 1U or 2U CubeSat, that would be 10% or 5% of the maximum mass. Not exactly what I would call small.

[Error404brain]

All this talk about propulsion systems is good and all, but is it even possible to put one on a CubeSat cheaply? Well, it probably is, but it'd need to be something simple like a plain old RCS powerd engine. But, we should do something unique, And oir Kerbal/unique options are:

GTO

Debris de-orbit tech demo

Pulse propulsion

Ion propulsion system(Less unique then the others)

Solar sail

Live visual footage feed

I didn't put the Lunar or interplanetary ones because those are essentially impossible for our first mission.

1) Don't even think about it.

2) might be feasible. But still useless and not kerbal.

3) So, how do u intend to get someone to put a bomb on their millions of dollars launchs ?

4) Feasible.

5) we can try.

6) Someone can hack the nasa for us ? Probably not.

Otherwise, we can inflate a module in space and monitor the way it's affected in space.We can even try a patchwork for the inflatable module, thus doing moar science:cool:

[Aghanim]

If we go with a 1U or 2U CubeSat, that would be 10% or 5% of the maximum mass. Not exactly what I would call small.

Well, I stand corrected. But now, the discussion is going pretty much nowhere. We cannot even think of our main objective. Solar sail? No, the forces are too small. Tether? Same problem. Deorbit demo? Space navigation is an issue. Leaving Earth? More issues. Most of the easy thing has been taken by other crowdfunded cubesat.

Doing a laser communication experiment, sending some data? Nope. Unless they can also receive the data by their own, it's probably will look like a scam.

Sending KSP stuff to space? Why didn't we use high altitude balloon or sounding rocket?

Doing SSTV? Sending out something space related might work, like that Portal SSTV transmission.

Edited July 16, 2014 by Aghanim

[Duxwing]

I did some math on the tether. A 10cm x 10cm cross sectional area will generate 18μN of drag (ballistic model) and up to 7.8mA of current at 300km. (3x10^-11kg/m³) At field strength of 40μT, which is pretty typical near Earth surface, that's just 0.3μN per meter of tether. So the tether would have to be at least 60 meters long just to compensate for the drag of the cubesat itself. And it will generate its own drag as well. The tidal force is barely sufficient at these scales as well.

Tethered electromagnetic drive is obviously a workable principle based on these numbers, but not for a cubesat. You need a significantly larger satellite to do a good demo of it.

Pity. It would have been a great project. But there are some other propulsion methods that can be looked into.

What if we used moar cubes? One cube could control the satellite whilst the other held the tether. The "hook" would be that the satellite's orbit, like that of all Kerbinar objects above 70km, would never change.

-Duxwing

[Error404brain]

So, the problem for orienting the craft is solved. Orient at the sun and it's good

One problem solved. Just thousand of them left.

[PakledHostage]

And exactly how far can you transfer this data?

We've done over 50km using a directional yagi antenna. Transmitting from/to orbit is obviously more challenging but the point is that an RF link that can be used to uplink/downlink data can also be used to transmit images. They won't necessarily be high quality images and, as I wrote earlier, I realise that the devil is in the details. But you can't dismiss the possibility with the wave of a hand.

Edited July 16, 2014 by PakledHostage
Spelling

[Nicholander]

Here's an idea for what we could do in LEO: It could be 2U, and one of cubes would have a pressurized area with some (Very small) plants in it, and we could monitor them. And sky walker, you're probably going to say that a pressurized area would be impossible, and if it is, let's find another thing to do in LEO.

[Kryten]

Streaming video feed from a 1U cubesat was achieved by Ecuador's 'NEE-01 Pegaso'; albeit with much higher investment than would generally expected for this kind of mission.

Edited July 16, 2014 by Kryten

[Error404brain]

Inflatable module. Let's try it. We might even put plants on it (we does need some chemist who can give us a reaction for it)

[Sky_walker]

We've done over 50km using a directional yagi antenna. Transmitting from/to orbit is obviously more challenging but the point is that an RF link that can be used to uplink/downlink data can also be used to transmit images. They won't necessarily be high quality images and, as I wrote earlier, I realise that the devil is in the details. But you can't dismiss the possibility with the wave of a hand.

Well then, that's much more than expected. Congratulations Making a transmitter that works fine at the range of 50 km is an achievement on it's own. Well done!

But yea - pointing at the target is a major challenge. Both: for receiver and transmitter.

Here's an idea for what we could do in LEO: It could be 2U, and one of cubes would have a pressurized area with some (Very small) plants in it, and we could monitor them.

And sky walker, you're probably going to say that a pressurized area would be impossible,

As far as I know - it won't pass through the tests. No living thing is allowed on a launch vehicles. There are very strict rules about contamination with biological matter.

As I said before - read the Ariane 5 user manual in my footer. It's interesting from a KSP rocket builder perspective, but also contains tons of info about qualification tests satellites need to pass before getting on a launch vehicle.

You're one of the most active users in this whole topic, you really, really, really should read it carefully from the first page to the last one.

Edited July 16, 2014 by Sky_walker

[cpast]

Most civilian GPS systems do not work in orbit - they have velocity/altitude limits, to prevent them being used in missiles (remember - GPS was originally developed as a military system, and is run by the Air Force). If the US government supports your project, you can get receivers that will work in orbit, but you need special receivers.

For pulse propulsion: Good luck getting a launch provider to take such a satellite. Keep in mind that the Cubesat design spec prohibits pyrotechnics, and any system with over 100 Watt-hours stored chemical energy has to be analyzed on a mission-by-mission basis (and probably fewer launch providers would want to take them). Propulsion has to comply with a specific standard, which may or may not account for pulse propulsion (the three kinds it mentions that I can see are solid rockets, cryogenic, and hypergolic).

[Error404brain]

"But yea - pointing at the target is a major challenge. Both: for receiver and transmitter."

We have the orbit informations.We have the satelit orientation. That's not even a problem dude.

[Aghanim]

http://web.archive.org/web/20140309023144/http://exa.ec/history.htm

On April 25, 2013 at 23h13 local time, onboard a LM2D rocket taking off from the JiuQuan Cosmodrome the NEE-01 PEGASO launches into space, 13 minutes later is injected into orbit and more than 4 hours later a radio amateur relays the first signal to CCVE ground control in Guayaquil, The National Government transmits the launching operation in national TV and the President sits in the CCVE ground control, commanding the mission is Cmdr. Ronnie Nader who declares mission success at 23h27 with the historic words "Welcome to the sky PEGASO, Welcome to space Ecuador"

On May 16, 2013 at 10h39 local time, from the Space flight Control Center in Samborondon the first public live video feed from NEE-01 PEGASUS is received and injected into the Internet, the mission director, Cmdr. Ronnie Nader, establishes the link with the satellite and receives it with the words "Welcome home PEGASO". The satellite transmits video and audio signals through EarthCam.com via Internet, it is reported that more than 3 million people around the world watched its transmission

On the night of May 22, 2013 EXA is notified by the JSpOC of USSTRATCOM of the close approach for NEE-01 PEGASUS with the SCC-15890 object, the remains of a Russian Tsyklon-3 rocket launched in July of 1985, EXA finds out by sources in Russia that this object travels surrounded by a cloud of small particles and debris, and in the night of May 23 2013, at 00h38m17s NEE-01 passes through this cloud, probably coalmining with small particles and losing attitude control violently. Surprisingly, NEE-01 survives the event and electronics remain 100% operative, due the heavy ant radiation shielding known as NEMEA and invented by EXA, but the HERMES-A ground station is unable to decode the transmission due a huge polarity error, After 5 days of monitoring and evaluation EXA finds out that the satellite is recoverable, on May 28 the Mission Directorate starts the PERSEUS recovery operation, with a nominal duration of 3 months.

In July 2013, EXA's Space Operations team realizes that it will not be possible to recover the signal of the NEE-01 from ground, but it should be possible to do that from an space based platform, then begins the PERSEUS project: The design, construction, installation and testing of a micro repeater unit onboard de NEE-02, which was being readied to be launched in November.

In August 28, EXA concludes the signal recovery operation for the NEE-01 PEGASUS, which transmitted successfully until May 23 before sustaining a close approach with debris from an old soviet rocket, the satellite is put into hibernation mode, but not completely shutdown, its reentry into the atmosphere is predicted for the year 2023.

November 21, 2013 at 02h10m11s local time, the NEE-02 KRYSAOR, second Ecuadorian satellite lifts off towards the orbit onboard a Russian Dnepr RS20B, this launch becomes world record for injecting 33 satellites into orbit at once, at 02h25m13s the NEE-02 KRYSAOR is delivered into its planned orbit. It carries onboard the PERSEUS device.

January 25, 2014 at 09h58m02s EXA's Space Operations team establishes contact with the NEE-02 KRYSAOR publicly from the CCVE installations in the ECU911 Samborondon and begins audio/video transmission from 750km height over the Atlantic ocean at more than 3000km away. The President joins the national TV broadcast at 10h01m, Cmdr. Ronnie Nader, head of the team informs the President the existence of the PERSEUS device onboard the NEE-02, designed to recover the signal of the NEE-01, the device is activated and at 10h05m58s the PEGASUS's audio transmission can be heard, identifying itself as the first Ecuadorian satellite and begins to transmit the national anthem, Nader pronounces the words: "Mr. President, We have recovered PEGASUS..." and the country explodes in joy. Ecuador becomes the only nation in the region to attempt and execute such operation in space and it is also the first time in history that a nanosatellite is recovered in orbit by another nanosatellite. The NEE-02 also transmits the song "We are all Astronauts", composed by the national singer AU-D (Martin Galarza) to honor PEGASUS, who then becomes the first Ecuadorian artist to broadcast from space.

That was an interesting story...

[Nicholander]

So sky walker, is an inflatable module possible on CubeSat, as Error404brain was saying.

[Aghanim]

@Error404brain: Pointing is hard. This is why I say omni antenna is a cheat, they doesn't need any pointing to be useful. But directional antenna needs pointing

[Error404brain]

@Error404brain: Pointing is hard. This is why I say omni antenna is a cheat, they doesn't need any pointing to be useful. But directional antenna needs pointing

That's hard, okay. But using math it's easy, IF both transmitter and receiver can be precise enough.

[Sky_walker]

http://web.archive.org/web/20140309023144/http://exa.ec/history.htm

That was an interesting story...

...about a government-sponsored cube sat with an actual scientists working on it, not just random forum members of a random forum.

So sky walker, is an inflatable module possible on CubeSat, as Error404brain was saying.

If he says so. It must be.

[Error404brain]

...about a government-sponsored cube sat with an actual scientists working on it, not just random forum members of a random forum.

I am quite sure that our space program is way better engaged than, for say, congo's one (2 explosion on the launch pad. one explosion in the near farm).

And random mean that someone could also be the top executive on the NASA.