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Unmanned Spaceflight.com _ Private Missions _ Cubesat 10x10x10cm 1kg Payload
Posted by: paxdan Sep 15 2005, 06:53 PM
I'm sure many of you will be familar with the http://littonlab.atl.calpoly.edu/ project, in fact some of you may well have worked on one. 
So lets hear it, what would you do with a 10x10x10cm 1kg payload in a CubeSat, beside the obvious like stick a camera in it and photograph your house.
Who knows, perhaps one day we may see the launch of the USF CubeSat 
Posted by: Bob Shaw Sep 15 2005, 08:27 PM
So lets hear it, what would you do with a 10x10x10cm 1kg payload in a CubeSat, beside the obvious like stick a camera in it and photograph your house.
Who knows, perhaps one day we may see the launch of the USF CubeSat
Back in the mid-1970s I actually tried to put together a coalition to build a small gravity-gradient stabilised satellite which would have specifically looked for fireballs in the Earth's atmosphere. Sadly, nothing came of the By your Own Bootstrap SATellite - BOBSAT - but I still have a number of drawings etc of it, including a hand-launch by an astronaut in the shuttle cargo bay! I'll try to dig them out and post them. This predated UOSAT, and was very much driven by the OSCAR amateur satellites - everything was to be off-the-shelf, and as simple as possible.
Posted by: djellison Sep 15 2005, 08:40 PM
Oh I LOVE cubesats...I have dozens of PDF's and PPT's about them. Infact, I get email from the Japanese 'Cutesat' which has a tiny camera in it 
I'd go with quite a long deployed antenna which would then create a nice gravity gradient to keep the spacecraft orientated to earth - perhaps deployed on a reel. To be honest, I think a camera is going to be the #1 cool thing to have on board, but I'd TRY and do pushbroom - not single shot. Basically - schedule it image at the best time of each orbit based on minutes after the arrays get over a certain voltage. Then, do as much as the memory can handle, and then keep it onboard until the next downlink pass.
The real problem is downlink capacity though - it's quite slow.
Cubesat's are just - JUST - too small to be brilliant, but a double cube sat ( 20x10x10) probably gives you enough mass and volume to have the power to do good imaging with downlink.
Actually - I'm surprised the Planetary Society havnt put together a cubesat proposal - it's just hard to find a scientific goal for one - apart from taking cool picture.
Doug
Posted by: paxdan Sep 15 2005, 09:25 PM
Doug
The cool pictures part is of course paramount. Heck slap a bunch of filters on it and you got your self some multispectral capability.
However instead of looking inward, why not look out. Why not turn it in to a dedicated multispectral planetary scope. Kind of the equivalent of a webcam + telescope beloved of amateurs but in space.
The science goals could be to image all the planets in 6 wavelengths. Pick at least one that can't be done from the ground due to the atmosphere and use that as your rational.
Regarding Jupiter storm observations, you metioned that there was interesting amateur work being done on storm rotation velocities from the ground using amateur kit, well do it from space instead.
OK so a mini observatory in space is going to be far more complicated, however, gyros for these CubeSats are an off the shelf component, you could even make sure that if all the pointing capacity failed you could still do earth observation, by having a default gradient stable postition for which the camera pointed at the earth.
Of course this is still pretty picture science but not beyond the realm of possibility
Posted by: Bob Shaw Sep 15 2005, 09:48 PM
Here's an illustration of BOBSAT as promised.
The upper 'cube' of BOBSAT enclosed the battery pack and instrument deck at launch. On-orbit, it would be ejected by springs (or manually) from the host vehicle and the upper and lower segments would be forced apart by pre-sprung steel tapes. Power would be fed via a cable to the battery pack. The whole structure would be wobbly, with the expectation that after several orbits the dissimilar masses would be gravity-gradient stabilised, but wobbling in a predicatable fashion (as identified by the radio signals from the satellite). The upper cube would have solar cells on five sides, and the battery pack would have solar cells on the base, so that whatever the orientation with regard to the sun there would still be some cells generating electricity. Twin boom antennae would protrude from the battery pack.
The sole experiment would be a I/R bolometer, and it was intended to quantify the number of fireballs entering the Earth's atmosphere.
Posted by: djellison Sep 15 2005, 10:02 PM
You'd struggle to justify putting a tiny tiny scope in orbit and show a benefit compared to a £1500 9" scope on the ground - the work of Damien Peach with a modest scope and good seing is utterly remarkable. Canada has a suitcase size sat that does excellent work for extrasolar planets, but thats an order of magnitude or two outside the scope (no pun intended) of a Cubesat.
Cubesats to date have been mainly an engineering exercise ( and a superb one ) - but I'm sure there's something they could really do...maybe fields and particles with a cluster of a few of them - who knows. They need a 'killer ap' - and suddenly, once you've got $200k, and a spare 10kg on a Falcon 1, you've got something amazing.
Doug
Posted by: tfisher Sep 15 2005, 10:19 PM
I would like to have a cubesat whose goal is to return continuous brightness measurements for one of the known transiting extrasolar planet stars. There are I think 8 of these at current count, all of which have one known planet transiting at a period of a few days. The science return potential is good, giving a continuous data stream on something the pro telescopes only look at very occasionally. Maybe it would even catch something great, like small variations in the transit timing indicating more bodies in the system. And even if the cubesat dies within a week, still that gives a couple of transit curves so some good results.
So how to design such a thing? You need a ccd behind whatever telescope you can fit (a camera lens, probably). (TrES-1, for instance, has a magnitude 11 star, and the transit was discovered by a telescope with a 10cm primary...) You need enough computer to read the ccd, pick out the right star, and transmit the measured brightness. You need enough antenna to broadcast the result back to earth and to listen for a kill signal from the ground. You need some power source, maybe a small solar panel. And, perhaps most challenging, you need some way to get the thing pointed in the right direction and keep it there.
I'm picturing two ipods running linux, one at a side and one at the back of the box. Pointing would be accomplished by spinning up or spinning down the hard drives, with a goal of getting the satellite spinning with the spin axis pointed at the star. Automated pointing would be done by star tracking in the ccd image. Attach a tape-measure antenna and put solar cells on the sides.
Does that sound plausable?
Posted by: Bob Shaw Sep 15 2005, 10:34 PM
So how to design such a thing? You need a ccd behind whatever telescope you can fit (a camera lens, probably). (TrES-1, for instance, has a magnitude 11 star, and the transit was discovered by a telescope with a 10cm primary...) You need enough computer to read the ccd, pick out the right star, and transmit the measured brightness. You need enough antenna to broadcast the result back to earth and to listen for a kill signal from the ground. You need some power source, maybe a small solar panel. And, perhaps most challenging, you need some way to get the thing pointed in the right direction and keep it there.
I'm picturing two ipods running linux, one at a side and one at the back of the box. Pointing would be accomplished by spinning up or spinning down the hard drives, with a goal of getting the satellite spinning with the spin axis pointed at the star. Automated pointing would be done by star tracking in the ccd image. Attach a tape-measure antenna and put solar cells on the sides.
Does that sound plausable?
I think the attitude control via HDU technology is very interesting indeed - if you've ever tried to move a spinning HDU then you'll find quite surprising force is needed (depending on the way you want to turn it). Of course, you'd still need a way to dump the rotational energy (if I can put it that way) from time to time. Electromagnetic torque devices powered by solar panels, with stellar observations taking place only on night-side passes, perhaps?
Posted by: paxdan Sep 16 2005, 11:39 AM
I had a look at the Damien Peach site, his work is stunning and represents just how far amateur ground based observation has come. now, i guess the thing to do would be to work out if it is possible to beat the resolution witha smaller scope in space. With a bit of ingineuty i'm sure you could design a extendible scope that would fit in a 10x10x10 cube which would produce results comparible to his work if not better.....
Posted by: Bob Shaw Sep 16 2005, 01:26 PM
Here's a notional 'AstroCube2' dual cubesat astronomy satellite, using HDU-based gyro stabilisation, magnetic torque de-spin, and with an 8cm or thereabouts telescope. Note the absolute lack of extending or moving parts other than the HDUs. Some form of 'Reactolite' or similar coating on a window over the telescope aperture would protect the interior from direct sunshine, and the exterior surface would be covered in solar cells. Differential GPS might be a valuable add-on. I don't imagine you'd do any imaging with this class of equipment, but light-curves or spectra would be practical goals.
So, how are we gonna build it?
Bob Shaw
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Posted by: djellison Sep 16 2005, 01:29 PM
Looking at a typical cubesat, that double cubesat hasnt set aside enough room for the basics, such as the radio, central control, power and modem hardware. It's takes about 75% of a full cubesat just to do the basics, let alone anything else.
Tell you what WOULD be cool....
interplanetary cubes
Doug
Posted by: Bob Shaw Sep 16 2005, 01:33 PM
Tell you what WOULD be cool....
interplanetary cubes
Doug
Doug:
If anyone can figure out how to build a tiny ion-engine, then there's loadsa spare mass capability to GTO, then just spiral out... (a la SMART-1).
Bob Shaw
Posted by: djellison Sep 16 2005, 01:54 PM
Need a lot of power and a high pressure Xenon tank. Wonder if it could be doable in a tripple cube.
Doug
Posted by: paxdan Sep 16 2005, 03:38 PM
Doug
the power could come from a set of extendable solar panels, who says that once deployed it has to remain constrained to a 10x10x10 cube. I jsut spent an hour in a boring meeting trying to figure out how to get a tiny telescope deployed from a 10x cube. with a single pivot point. We need to start thinking outside the box....
Posted by: djellison Sep 16 2005, 03:48 PM
Oh - extandorama - I've seen designs that include that (infact, I think Cutesat, the japanese one does )
Posted by: Bob Shaw Sep 16 2005, 03:49 PM
The absolute minimum of deployment is probably the way to go - movement of parts=risk to both the CubeSat and the host vehicle, and leads to weight gains, spiralling cost etc. KISS is the motto - it's not Rocket Science, after all, just building... ...er... ...maybe it is.
Posted by: Bob Shaw Sep 16 2005, 03:54 PM
Did I mention that an old friend of mine is selling places on Dnepr launchers, and that if persuaded he might be the very man to find a launch slot? All we need is a spacecraft...
Posted by: ljk4-1 Sep 16 2005, 04:41 PM
DIY satellites reinvent the space race
New York Times September 14, 2005
CubeSat is giving students and
companies the opportunity to build
and launch functional satellites
into low Earth orbit at low cost....
http://www.kurzweilai.net/email/newsRedirect.html?newsID=4840&m=7610
As for doing astronomy with very small satellites, WIRE is using its 2-inch star tracker for just that purpose:
http://arXiv.org/abs/astro-ph/0509444
Posted by: paxdan Sep 16 2005, 05:03 PM
Well lets do it then. seriously. You can buy a lot of the kit you need for the cubesats off the shelf, as someone else pointed out 75% of the volume of a 10x10x10 cube is taken up by standard stuff, CPU, battery, radio, gyro/mag-torque, etc... What we need to focus on is what you would do with a 10x10x2.5 (or eqivalent) 250g payload.
The thing that got me thinking is that most telescopes are empty volume. instead of launching that empty volume, why not launch the volume filled with the support stuff, pack all the brains into that empty space for launch then clear the tube once on orbit.
Now the clever bit is to design it so that the mirrors and camera remain permenentaly fixed relative to each other. i.e., none of the deploy would be about moving the mirrors accurately, just clearing the tube. I have a design in mind that is essentailly a reflecting telescope with a single sprung hinge which rotates out the brains of the scope from the light path leaving behind a clear tube, you wouldn't even need fine control over the movement, it's a dead cert gross movement deploy. You turn a 10x10x10x satalite in a 10x10x20 telescope on orbit with a single hinge. and bingo there is you amateur telescope in space.
the thing is it's such a simple way of doing it, i know it must have been done before, are there any orbiting telescope that have used a similar deploy mechanism on orbit?.
Posted by: Bob Shaw Sep 16 2005, 10:26 PM
The thing that got me thinking is that most telescopes are empty volume. instead of launching that empty volume, why not launch the volume filled with the support stuff, pack all the brains into that empty space for launch then clear the tube once on orbit.
Now the clever bit is to design it so that the mirrors and camera remain permenentaly fixed relative to each other. i.e., none of the deploy would be about moving the mirrors accurately, just clearing the tube. I have a design in mind that is essentailly a reflecting telescope with a single sprung hinge which rotates out the brains of the scope from the light path leaving behind a clear tube, you wouldn't even need fine control over the movement, it's a dead cert gross movement deploy. You turn a 10x10x10x satalite in a 10x10x20 telescope on orbit with a single hinge. and bingo there is you amateur telescope in space.
the thing is it's such a simple way of doing it, i know it must have been done before, are there any orbiting telescope that have used a similar deploy mechanism on orbit?.
Paxdan:
I've never, ever, heard of an astronomical spacecraft which was built without that big hole in the middle (other than the James Webb chappie). I think mass/structure issues have tended to be the limiting factors, but with nanosats you may as well throw the rulebook away. For example, structural integrity in a 10cm cube, is, well, a given - so move on! If there's serious interest in actually building something - and between us, why not? - then let's build something! I'll make some discreet enquiries regarding a launch...
Bob Shaw
Posted by: um3k Sep 16 2005, 10:50 PM
My idea is of a 9cm apochromatic objective, 36cm* focal length, which is extended linearly outward using something along the lines of spring tension. I have no idea whether it could work or not, and I have not really thought about anything other than the optical setup.
Here is a sample image of M13 using the above setup with a KAF-3200E(ME) CCD. (NOTE: this is not a real image. It is a simulated image created from DSS images.)
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EDIT: Ignore this until I think about it more.
Posted by: djellison Sep 17 2005, 10:27 AM
Within the 'scope' as it were of a cubesat, you dont have THAT tight a control on orientation, even with electro magnetic or gravity gradient stability control. It might be worth checking out previously actively stabalised sats to see how much pointing accuracy they could muster.
I think a sensible, modest Cubesat is a sensible precursor to anything more bold.
Every few days I get an email from Cutesat...
Hello! This is XI MAIL.
* Message from us
This picture was taken over Japan.
* Status of XI-IV
Remaining Battery Level : 49.8%
Charging Current : 0.0mA
Electricity Generated : 0.6W
Temperature(+X Panel) : 24.7deg
Temperature(-X Panel) : 24.7deg
Temperature(+Y Panel) : 24.7deg
Temperature(-Y Panel) : 21.2deg
Temperature(+Z Panel) : 23.3deg
Temperature(-Z Panel) : 18.4deg
Temperature(Battery) : 21.9deg
Temperature(Transmitter) : 21.9deg
and the attached image was todays image
A 1024 x 1024 CCD camera - which could be commanded to take images as close to a given Lat/Long as possible would make an excellent resource and a superb outreach project - and as a second string, perhaps fly on one of the 6 sides - some prorotype solar cells as an engineering project.
iirc - baisc cube-sat kits are around $10k ish.
http://www.cubesatkit.com
http://cubesat.arizona.edu/rincon_sat/structures/cad.cgi
http://littonlab.atl.calpoly.edu/
http://www-ee.eng.hawaii.edu/~cubesat/
I'll tell you what genuine contribution I can make....pretty 3d pictures of a cubesat in 3ds max
doug
Posted by: paxdan Sep 17 2005, 11:18 AM
A 1024 x 1024 CCD camera - which could be commanded to take images as close to a given Lat/Long as possible would make an excellent resource and a superb outreach project - and as a second string, perhaps fly on one of the 6 sides - some prorotype solar cells as an engineering project.
doug
You are of course correct, keep it very simple. With a simple camera (or two: one narrow, one wide angle, one mounted pointing down the other horizontally) on a gravity gradient stablised craft there are several things that could be done.
Daylight photography of given lat and long as suggested by Doug,
I/R bolometer to measure fireballs entereing earths atmosphere as outlined by Bob Shaw.
You could use the CCD as a cosmic ray detector to measure the flux.
And the one that interests me would be night-time imaging of large storms to hunt for sprites and all the other as yet not fully understood upper atmosphere phenomenon associated with lightning.
The use of high sensitivity CCDs and optical enhancement routines during the night pass would enable this, and given their recent discovery and the paucity of imaging of these phenomenon returned from space, i think it would make a valid objective for a cube sat.
i would love to hear as many suggestions as possible for worthwhile imaging projects that could be pulled of with a pair of cheap CCDs in orbit.
I have edited this post for spelling.
Posted by: Bob Shaw Sep 17 2005, 12:24 PM
I've just had a flash of inspiration. It doesn't refer *exactly* to the CubeSat discussion, but *does* grow from it!
Here it is:
Use HDU technology to build a redundant array of inexpensive gyroscopes. Not RAID, but RAIG. You bolt together a goodly number of HDUs with bespoke controller cards and run 50% of them (with full SMART-style HD diagnostics running). As the running drives fail, you simply turn them off and fire up a spare. MTBF is verrrry high on HDUs now, measured in the hundreds of thousands of hours. The running HDUs keep the spares warm; the spares act as heat-sink for the running ones. And the cost? Tens of thousands of Dollars, Pounds, ECUs, whatever - ie, CHEAP!
Now, is that a good one, or what? (He purred).
Bob Shaw
Posted by: Bob Shaw Sep 17 2005, 01:05 PM
Daylight photography of given lat and long as suggested by Doug,
I/R bolometer to measure fireballs entereing earths atmosphere as outlined by Bob Shaw.
You could use the CCD as a cosmic ray detector to measure the flux.
And the one that interests me would be night-time imaging of large storms to hunt for sprites and all the other as yet not fully understood upper atmosphere phenomenon associated with lightning.
The use of high sensitivity CCDs and optical enhancement routines during the night pass would enable this, and given their recent discovery and the paucity of imaging of these phenomenon returned from space, i think it would make a valid objective for a cube sat.
i would love to hear as many suggestions as possible for worthwhile imaging projects that could be pulled of with a pair of cheap CCDs in orbit.
I have edited this post for spelling.
Paxdan:
I like the sprites idea - and have thought of a way to reduce data transmission requirements fairly drastically.
As you probably know, many current digital cameras offer a 'time-machine' facility, where they constantly stare at a scene and record images to a temporary buffer. When you press the shutter, the last ten or so images are written to long-term storage. So, you see the splash as the swimmer dives into the water, and get the picture you really wanted a quarter of a second beforehand.
So, to record sprites, you have camera which 'stares' and records to temporary storage. You download thumbnails (a la MER) and volunteers check them (a la SOHO comets), or you use software if that's too slow. Only then do you actually download the full-sized images. Most sprites will be found between Latitudes X and Y (name a figure!) leaving many northern hemisphere passes free for downloads.
So, the initially high burden of recording images is made much more acceptable.
Imaging will always be costly, though, and anything that would reduce the number of images seems like a good idea. So, my next thought: Don't look down, but instead look sideways - with a slightly wobbly CubeSat, you can scan the horizon, and perhaps see many more events with much less real estate covered (plus, by using the 'time machine' technique, you could hope to get 3D imagery, and all the rest).
Phew!
Too much inspiration for one day!
Bob Shaw
Posted by: um3k Sep 17 2005, 05:17 PM
How about a solar telescope? If a little car that drives itself towards a light source can be made as a science fair project, then surely a cubesat that points itself at the sun can be created, right?
Posted by: djellison Sep 17 2005, 06:21 PM
Having it intelligent enough to know which way to point is easy
GETTING it to point in that direction is hard. micro-gyros are expensive, electromagnetic stabilisation is slow.
Doug
Posted by: um3k Sep 17 2005, 07:05 PM
GETTING it to point in that direction is hard. micro-gyros are expensive, electromagnetic stabilisation is slow.
Doug
For the sun, all it needs is a sun-sensor and some way to spin to the right orientation, possibly mini reaction wheels. I don't think it would really need gyros.
How about this: 5 very low precision sun position sensors (just a light-sensitive chip), one for every side but the front; 1 low precision sun position sensor (a fisheye lens and a ccd); 1 medium precision sun position sensor (a medium focal length lens and a ccd); and the final positioning will be done with the telescope itself. And yes, I have loads of faith in modern miracles of miniaturization.
Posted by: Bob Shaw Sep 17 2005, 08:48 PM
How about this: 5 very low precision sun position sensors (just a light-sensitive chip), one for every side but the front; 1 low precision sun position sensor (a fisheye lens and a ccd); 1 medium precision sun position sensor (a medium focal length lens and a ccd); and the final positioning will be done with the telescope itself. And yes, I have loads of faith in modern miracles of miniaturization.
As a technology demonstrator, something that can seek the Sun is probably about as easy as you can get - and I'd think in terms of light-sensitive diodes, not even chips! You're talking about an analog control system, or possibly something which might be considered as a neural network, with 'learning' to account for biased inputs. The HDU gyro idea seems like an ideal reaction control method, too - but you'll still need to de-spin at some point. Perhaps a gravity gradient default attitude would do the job, but that might require a boom - and I don't much like moving parts (spinning, that's fine!). If the system works, apply it to the next satellite...
Posted by: hendric Sep 18 2005, 07:27 AM
Don't hard drives require air to levititate the heads off the platters? What happens in space? Did those previous experiments seal the HD's in their own atmo?
Posted by: Bob Shaw Sep 18 2005, 11:35 AM
HDUs certainly used to have so-called 'flying heads' which 'flew' just above the platter surface, that's true. I was recently told that there are other forces also involved, but in fact that wouldn't matter - the HDUs wouldn't be data storage devices, but momentum storage devices - you'd probably strip out the head components in the build process. I don't know what, if any, form of lubrication is used in HDUs, so outgassing/drying might be a problem in an airless environment.
I'd expect flash memory to be the medium of choice for data storage.
Posted by: Bob Shaw Sep 18 2005, 05:44 PM
As promised, here's an illustration of a manual launch option for my late 1970s BOBSAT proposal - the battery pack is shown in the act of extending from the shell.
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Posted by: djellison Sep 19 2005, 12:53 PM
Cameras on Cubesat - interesting .doc
http://ncube.no/documents/Camera_Payload_Report.doc
Doug
Posted by: paxdan Sep 19 2005, 02:41 PM
http://ncube.no/documents/Camera_Payload_Report.doc
Doug
404 error on the link.
Posted by: ljk4-1 Sep 19 2005, 02:42 PM
Let's go one step smaller - how about nanoprobes? A fleet of nanotechnology probes exploring the Sol system. If we lost a few of those, it would be unfortunate but not an end to the mission.
How close are we to developing such machines for space exploration?
Posted by: djellison Sep 21 2005, 03:35 PM
I got all excited and started to build a card model of a cubesat
http://www.cubesat.auc.dk/fun1.html
Doug
Posted by: Bob Shaw Sep 21 2005, 03:45 PM
http://www.cubesat.auc.dk/fun1.html
Doug
Doug:
Snap!
Bob Shaw
Posted by: djellison Sep 21 2005, 03:48 PM
I think I'll finish mine tonight...I'm cheating and using double sided tape...but then I'm taking the time to put a bit of card on the back of the main panels for a bit of added strenth.
Not sure about the antenna component though - it should be really fine wire, but then the cat would take her eye out on that so I'll just go with what's printed
There's a model of the Japanese cute-sat somewhere, but it's onle 1/2 scale and isnt as good as that one
Doug
Posted by: Bob Shaw Sep 21 2005, 06:53 PM
Not sure about the antenna component though - it should be really fine wire, but then the cat would take her eye out on that so I'll just go with what's printed
There's a model of the Japanese cute-sat somewhere, but it's onle 1/2 scale and isnt as good as that one
Doug
Doug:
I printed out onto heavy photo paper, then laminated it - a dab of super-glue and it'd fly!
I'll post a pic, in a day or two.
Bob Shaw
Posted by: djellison Sep 21 2005, 07:12 PM
You've got a laminator - that's cheating
I totally screwed it up last night - trying to make a cube, not noticing that the corners are turned inside out (you'll know what I mean)
I'm almost done
Doug
Posted by: djellison Sep 21 2005, 07:16 PM
Damnit - if I'd have thought of this first
http://www.milliondollarhomepage.com
I'd be building a real one for UMSF
Doug
Posted by: Bob Shaw Sep 25 2005, 12:51 PM
Here's a Space.Com article on the SSETI student satellite and cubesats:
http://www.space.com/businesstechnology/050921_techwed_sseti.html
Posted by: Myran Sep 25 2005, 07:32 PM
They have proposed a Cubesat Moon lander also, 1 kg and that includes a miniature rover with a camera! *Blink*
Posted by: djellison Sep 26 2005, 11:33 AM
Took the cad file from the cubsatkit website and rendered something up
Doug
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Posted by: Bob Shaw Sep 26 2005, 11:47 AM
Doug
Doug:
That seems helluva over-engineered!
Plywood and balsa, that's the way to go...
Bob Shaw
Posted by: djellison Sep 26 2005, 01:11 PM
Is Balsa space certified?
Doug
Posted by: Bob Shaw Sep 26 2005, 03:37 PM
Doug
Doug:
Yes! Ranger-A, LM legs...
Bob Shaw
Posted by: paxdan Oct 9 2005, 02:49 PM
NewScientist article about http://www.newscientistspace.com/article/mg18825205.600-offtheshelf-mini-satellites-herald-space-revolution.html
Posted by: Rakhir Oct 27 2005, 08:04 AM
SSETI Express launched.
http://www.esa.int/esaCP/SEMOKZ538FE_index_0.html
Rakhir
Posted by: djellison Oct 27 2005, 08:55 AM
http://www.esa.int/esaCP/SEMCMZ538FE_index_0.html
http://littonlab.atl.calpoly.edu/
Rakhir
And with it - three new cubesats
Doug
Posted by: ljk4-1 Oct 27 2005, 12:56 PM
Doug
What are the three CubeSats on this launch besides SSETI? Cornell had one they were going to launch - was this the mission? I didn't see it on the ESA news item.
Thanks.
Posted by: Rakhir Oct 27 2005, 01:30 PM
Thanks.
The three CubeSats are :
- Ncube II
It contains an automated identification system (AIS) used to receive GPS signals. Ncube II was developed by Norvegian universities.
- UWE-1
The main objective of UWE-1, is to conduct telecommunication experiments related to the optimisation of an internet-related infrastructure for space applications.
It was developped by a German university.
- XI-V
Its primary mission is the demonstration of newly-developed solar cells in space.
It was developped by the Intelligent Space Systems Laboratory (ISSL) of Tokyo.
More details on : http://www.esa.int/SPECIALS/sseti_express/SEMN9Z708BE_0.html
Rakhir
Posted by: djellison Oct 27 2005, 01:40 PM
As I understand it - XI-V is one of the development models for XI-IV (which emailed me lovely earth pics every now and again 
) - but with a better, 320x240 camera.
Of the three - UWE has been detected fine, NCube2 may have had a beacon signal detected, no news from XI-V yet.
Strangely, NCube 1 was a failure, but they've taken it's engineering model camera and adapted it for SSETI itself - 1280x1024 images with approx 100m/pixel resolution.
Doug
Posted by: ljk4-1 Oct 27 2005, 01:58 PM
) - but with a better, 320x240 camera.Of the three - UWE has been detected fine, NCube2 may have had a beacon signal detected, no news from XI-V yet.
Strangely, NCube 1 was a failure, but they've taken it's engineering model camera and adapted it for SSETI itself - 1280x1024 images with approx 100m/pixel resolution.
Doug
Do you have any of those Earth images available to show us?
I like to keep track of the home planet now and then.
Posted by: djellison Oct 27 2005, 03:00 PM
http://www.space.t.u-tokyo.ac.jp/cubesat/index-e.html has a few
to be honest, they're terrible, but it's the thought that counts
Take enough of them...
Posted by: Rakhir Oct 28 2005, 03:14 PM
SSETI Express in safe mode due to an undervoltage caused by battery charging problems.
http://www.esa.int/esaCP/SEMWD7638FE_index_0.html
Signals from XI-V and UWE-1 have been successfully received at their respective ground stations.
Ncube2 students are still struggling to receive the first life signs from their satellite.
http://www.esa.int/esaCP/SEMSV5638FE_index_0.html
Rakhir
Posted by: djellison Oct 28 2005, 03:19 PM
2 for 3 on cubes isnt bad actually - given that they cost less than the average projects accounting error
Sad for the Ncube guys though - this will be their second lost cube 
Doug
Posted by: Bob Shaw Oct 28 2005, 10:20 PM
More coverage:
http://www.spaceref.com/news/viewpr.html?pid=18130
Bob Shaw
Posted by: Andrew Kalman Sep 13 2006, 12:11 AM
With Clyde Space now having announced a space-rated EPS for the CubeSat Kit, we have a more complete overview of the available masses and volumes for missions that base their satellites on our hardware. Here are some interesting numbers:
Structural masses (i.e. the masses of the complete empty structures of our CubeSat Kits, including all fasteners):
1U (10x10x10cm):
Total for 1U solid-wall: 251g
Total for 1U skeletonized: 166g
3U (10x10x30cm):
Total for 3U solid-wall: 521g
Total for 3U skeletonized: 321g
FM430 Flight Module (C&DH and COM processor): 81g
Microhard MHX-series transceiver: 66g
Solar Panel Clips: 9g
Clyde Space EPS (includes Li-Poly battery, estimated): 250g
So excluding payload, antennas and solar cell panels, a 1U skeletonized chassis + FM430 + MHX transceiver + Clyde Space EPS comes in at 572g, and uses up roughly the lower 45mm of the internal volume in the structure. So that means that you have roughly 400g for the antenna(s), solar panels and payload, and room for the payload inside a volume of roughly 96 x 96 x 40mm.
The real killer -- mass-wise -- is the Solar Panels themselves. Just the bare PCBs (in 0.062" / 1.5mm thickness) weigh 30g each. So 180g just to be able to mount your solar cells to panels on all six sides. Dropping to 0.031" (0.75mm) PCBs saves you nearly 100g (10% !) of mass of the satellite.
I noticed in this thread some discusson of the 2U (10x10x20cm) CubeSat. We've built and delivered 1U and 3U (solid-wall and skeletonized) units to customers. Haven't yet received an order for a 2U (or a 0.5U or a 1.5U), but all of these are easily implemented within our architecture.
Hope this helps,
Posted by: Ant103 Sep 14 2006, 09:35 PM
Incredible, amazing, astounding!!!
I have no words to explain my excitation when I've read this subject! 
So, it mean that anybody can build a 10 cm cube sized satellite?! It's incredible, I never have heard this adventure. It's so ... surealistic!
A few days ago, I planned (just for fun), to build a micro-spacetelescope (mini-hubble in other word 
). After, the launch will be did by Ariane5. But, If I have a good understanding of the Cubesat story, it will be cheaper by using the Space Shuttle? 
So, is ti possible to have more details on the how-to of the Cubesats, I'm very very very interest.
Posted by: djellison Sep 14 2006, 10:29 PM
I think they're a fantastic development. I don't think they're in the realm of good science observations ( some interesting measurements, but no optics etc) yet..but 2u/3u sats could certainly include something interesting
For your average private individual - it's still not 'cheap' - I've seen lots of figures from about $10k to about $200k for a full project. It depends if you have generous suppliers etc etc
I'd say it takes a handfull of experts - more than just one person - but not a huge team. It's not easy - and there's no guarentees ( as the tragic recent launch failure reminds us all ) - but it's a fascinating and exciting developmetn and I'm always interested to see what the inginuity of students and universities can think of to do with the platforum - and what Pumpkin have done is make it even more accesable by producing a kit.
Doug
Posted by: mcaplinger Sep 14 2006, 11:01 PM
I'm just curious, do you sell to non-US customers without an export license? I would think that some of this stuff would be classified as controlled by ITAR.
Posted by: Ant103 Sep 15 2006, 10:37 AM
And what about the launch cost? And the launcher, have we the choice between a small launcher (Delta...) or Space Shuttle? Or European launcher (I think about the next generation of small launcher propose by the ESA, named Vega)?
I made a little reflexion about a mini-scope, with a diameter of 70mm, Schmidt-Cassegrain or Maksutov for the optical system. The miror will be in the box and the second miror will be open and will extend after the launch on a distance of 30cm. I will draw schematics to explain my futur project.
Posted by: djellison Sep 15 2006, 11:01 AM
I don't think the shuttle would be used for these anymore. Converted Russian ICBM's make the bulk of the launch manifest for Cubesats - but using the PPOD, there's scope to launch them as a secondary payload on the other vehicles you mention, Delta 2/4, Atlas 5, Ariane 5, and in the future Vega etc. I think working with Cubesat teams is a sensible investment for the LV manufacturers. The students that build and fly these things are the same students that the major LV and astronautical engineering firms will want to employ in the future.... by spending the money on accomodating Cubesat PPOD's when volume and mass budgets allow, they're essentially giving experience to future employees - it's a good trade.
Just as an aside Andrew - is there any chance of the 1/2U, 2U and 3U chassis CAD files making it onto the website? I'm not a potential customer ( unless I win the lottery in which case I'll be turning into a philanthropist and funding several UK universities to start cubesat projects ) - but I do like looking at these things - even if just from a creative standpoint for making pretty picture http://www.unmannedspaceflight.com/index.php?act=Attach&type=post&id=1588
Doug
Posted by: Ant103 Sep 15 2006, 04:55 PM
Not very serious posting…
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Posted by: Andrew Kalman Sep 20 2006, 05:54 PM
http://www.unmannedspaceflight.com/index.php?act=Attach&type=post&id=1588Doug
One application of our model is not something I had originally envisioned, but it's pretty cool anyway. That is to simply take the model and run it through a rapid-prototyping (e.g. SL) machine, and then using it to attract attention, for fundraising, brainstorming, etc.
--Andrew
Posted by: Andrew Kalman Sep 20 2006, 06:00 PM
This is a complex subject. To summarize (very briefly), because what we do is fully in the public domain and because the primary mission is research, then we are able to sell these to non-US customers without an export license.
That said, there are items we will not sell (because they would require an export license, which would put them out of the price range of CubeSats), like solar panel assemblies or cells.
That's one reason why we are partnering with companies like Clyde Space in Scotland, who offer a plug-and-play EPS solution for the CubeSat Kit, and who also are in the business of solar panel manufacturing.
Posted by: J.J. Nov 23 2006, 05:41 PM
I have simple tastes.
Assuming I had the expertise, two experiments I could do on a CubeSat would be:
--Monitoring civilian FM and AM ground stations as the satellite passed overhead.
--Using said transmissions to "listen" to meteors.
--Measuring the variation of radiation with each orbit.
These wouldn't be groundbreaking, but I would find them interesting.
Posted by: Andrew Kalman Dec 5 2006, 10:27 PM
3U models are now online, in a variety of CAD formats:
http://www.cubesatkit.com/content/design.html
Posted by: Bob Shaw Dec 25 2006, 11:11 PM
Perhaps the way forward *isn't* with solar cells, but with solar-powered Stirling Engines; pointing might be fun, though...
...in fact, simply flying a Stirling Engine in it's own right would be a good engineering mission!
http://www.gyroscope.com/d.asp?product=SOLARSTIRLING
Bob Shaw
Posted by: Bob Shaw Dec 26 2006, 11:07 PM
Another interesting prospect is on-line machining - design the CAD model, hit [Enter] and a week later your components arrive...
http://www.emachineshop.com/
Bob Shaw
Posted by: helvick Dec 28 2006, 07:37 PM
Apologies for extending this slightly more OT but this http://www.bathsheba.com/uses suchhttp://www.exone.com/prometal.html to create exceptionally complex structures that would be flat out impossible to construct any other way.
Posted by: tuvas Dec 28 2006, 08:10 PM
One of the best uses for Cubesats is to do engineering tests. The two that were in the last launch from the University of Arizona had engineering purposes, and these were more than just seeing if student projects work. One was to do a test of a method of using a low-powered beacon to transmit data to earth, and the other was to test the effects of radiation on several components.
There are alot more things that could be done, but it takes a creative mind to come up with them. Any engineer can come up with a $4 billion dollar telescope that'll vastly improve our knowledge of the universe, but it takes a truly creative one to figure out how to do something new with such a small payload. Luckily most students have some sense of creativity.
Posted by: Bob Shaw Dec 28 2006, 11:30 PM
Great links - puts me in mind of the times I've tried to build tesseracts out of matchsticks. A seriously clever artist, making a real art/science crossover!
Bob Shaw
Posted by: djellison Dec 29 2006, 06:00 PM
I actually went as far as getting a quote for some turned metal wheels for a model of Thrust 2 I was thinking of making...
Once I found out how much it was going to cost...I stopped thinking about making it
Doug
Posted by: marsbug Jul 26 2007, 03:28 PM
http://asmo.arc.nasa.gov/mission_overview caught my attention a few minutes ago and here seemed the best place to post it. Not sure if it counts as a private mission, but apparently nasa supervision will be at arms length at least.
Posted by: nprev Jul 26 2007, 08:13 PM
Hey, that's a pretty neat idea... Can't think of something that might excite a group of students more than building their very own lunar orbiter!
OT here at least tangentally, but just can't resist adding an anecdote that so many here might appreciate. Couple of weeks ago I was in a meeting with my boss & his boss discussing spacecraft transport. I mentioned that the aircraft of choice for us, a heavy lifter, suffers from low enroute reliability. The big boss's response (paraphrased) was "Well, we need to influence the design process early enough so that our satellites are small enough to be carried on commercial planes." He went on & on, and my boss & I courageously bit our tongues almost completely off, patiently explaining that this might be possible in 15 or 20 years but right now contractually requiring major breakthroughs in solid-state physics and a dozen other disciplines might be, uh, kind of expensive & risky & of course vastly prolong development time...
Truly a Dilbert moment, and a prime example of why business majors shouldn't be involved even peripherally with engineering...well, at least not this one, anyhow... 
Posted by: Thu May 2 2008, 02:27 PM
I'm working on a proposal for a Cubesat mission in which the satellite will be placed on very low Earth orbit. Since orbital decay at low altitude will bring the s/c down in a few weeks -> now I'm in need of a tool that can help me predict the life time of the Cubesat on a particular orbit.
I've been searching on the net but it seems that there isn't so many tool like this available. Does anybody know of such tool or any web page that can help me to calculate the life time of a Cubesat (10x10x10cm, 1kg) on a circular 300x300km orbit?
Posted by: TheAnt Sep 11 2013, 12:59 PM
In related news:
http://www.astrobio.net/pressrelease/5674/inflatable-antennas-could-send-cubesats-farther
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