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Ask Slashdot: How Would You Build a Microsatellite?
Dishwasha writes "A fellow co-worker of mine turned me on to CubeSat; apparently there are commercial space companies that will launch CubeSat systems from their payload for a modest fee. Is anybody in the /. community involved in amateur microsatellite systems? How would I go about getting involved at an amateur level? Are there any amateur user groups and meetups I can join? I have limited background in all the prerequisites but am eager to learn even if it takes a lifetime. Any links to design and engineering of satellites would be appreciated."
Apparently that isn't the hard part, as the poster already identified a company that will do it.
You might want to get a ham radio license, and even if you don't, visit the website of Amsat (http://www.amsat.org), a worldwide group that has put many satellites in orbit. You are welcome to join even without an amateur radio license.
I'm an American. I love this country and the freedoms that we used to have.
Disclaimer: I have no personal experience doing this. I noticed on O'Reilly there is a cheap series of books by Sandy Antunes. I think surviving orbit will be your biggest challenge? No clue on the quality of those books ...
My work here is dung.
With this business philosophy, one could have regional offices that collect this knowledge and store documents of it in little cannisters. When someone in one region needs to access the knowledge from a different region, they could send a request and have that cannister (with the relevant document inside) sent along a pneumatic piping system, just like at the bank teller window. One could call this business The National Tube Service, or simply The Tubes(tm).
do() || do_not();
I would use tiny tools.
The Kruger Dunning explains most post on
The most important thing is to decide what you want your CubeSat to do. Are you out for a Sputnik style beacon that you can detect when it goes overhead? Are you going to be taking pictures of all the balloon cameras that didn't make it into space?
Once you decide what you are going to do, then you can start in on the design. Cubesat.org has all sorts of design guidelines, etc.
As for organizations, mailing lists, and the like, the external links on the Wikipedia page you linked into your article should provide an excellent starting point.
When our name is on the back of your car, we're behind you all the way!
Stanford and Cal Poly has been involved from early on and has a lot of experience with cubesat launches. UNM also has a program and I think UM and U of Utah Logan. Probably lots of others. Basically schools with a strong Aerospace program are likely to be involved and help with getting in contact with good people. You may, if you have interesting tech knowledge, be able to advise a group of students on a project they are already doing.
Also the air force schools do projects (AFA and AFIT) but they might be harder to work with.
Anyone can build anything, the question is, will it work when it gets there.
Space is a totally alien environment from habitable earth. It's like being in the desert Antarctic and the inside of a nuclear reactor at the same time. If you're in the sun it's very hot and out of the sun it is very cold. There no atmosphere and whatever particles are around can contain high energies. Many substances stable at atmospheric pressure become volatile. Special lubricants have to be used to avoid all kinds of issues with evaporation, freezing, or sticking. Solar flares can fry you.
Any leaks or evaporation from the satellite can cause it to spin out of control. Any control system failure is fatal. You don't get to test the unit in zero gravity before hand. Your solar and power storage have to deal with all the above issues. Oh, if your components get hot, they have to radiate the heat away, no convection to do the work for you.
Well, I would start with a bunch of nucleotides (A, T, G, and C), then assemble them into a DNA strand such that the same short sequence of nucleotides is repeated over and over again in the strand. That's all you need for a microsatellite, really. Doing this will not be easy, of course, without access to some very sophisticated lab equipment... Oh, wait -- you aren't talking about that kind of microsatellite. Moving along...
I was involved in a recent university project that launched a payload on a suborbital sounding rocket. Depending on your objectives, getting into Arduino or Beagleboard or Gumstix or some similar low-power microcontroller will really open up a lot of possibilities for you. We launched a capsule that radio'd back inertial data using largely off-the-shelf components from places like Sparkfun.
You will find much information on AMSAT (http://www.amsat.org) , JAMSAT (http://www.jamsat.or.jp) or AMSAT-UK (http://www.uk.amsat.org) for some of the amateur organizations around the world, they have been around for decades and have a wealth of experience and can use any offered help! Also get your amateur radio license and then you can access the existing birds that are up there, ARRL (American Radio Relay League) or RSGB (Radio Society of Great Britain) or other organizations are a good place to start. I can't seem to get links to work on /. so will have to leave it up to you to google the above acronyms to find out more.
I have built my share of down-converters and donated my share of money to get some of the satellites into orbit, it is extremely expensive to get something into orbit, not so hard building it in comparison, most of the expense is just getting it out of the gravity well and orbiting.
In fact if you go to the UK AMSAT web site they have a bit on the latest cubesat on there now :)
Buddha of compassion
It would be even better if there was a way for many different people to add information, make corrections, discuss the implications, and point others to places that contain additional resources.
It's easier to be a result of the past, but more fun to be a cause of the future! http://www.spacefinancegroup.com/
Or I may win enough in a lotto drawing to order a Falcon Heavy launch from Space X. Your pick.
This is irrelevant, but this line got me thinking. You are actually in the ballpark. Imagine that - space technology has gotten to the point where Joe Shmoe from Poughkeepsie could buy a lottery ticket, and a few weeks later start getting prepped for a trip into orbit on his own Falcon. Has anyone drunk a beer in space?
It's easier to be a result of the past, but more fun to be a cause of the future! http://www.spacefinancegroup.com/
A metal cube in low Earth orbit will equilibrate to about 25C if you cover the outside with solar cells and some reflective tape. The radiation environment isn't really all that bad below the Van Allen belts; use automotive grade parts and in general you'll be fine. No need to worry about lubricants because you shouldn't have any mechanical actuators (unless it's part of your payload or you really want to fly a reaction wheel). Good thermal ground planes in your boards and metal bosses tieing them to the structure will move heat away from components just fine. No need for a "point-or-die" solution, just put solar cells on all faces of your satellite; if you lose control authority (e.g. computer crash) you still generate enough keep-alive power. Gravity doesn't really have any impact unless your payload is a mechanical actuator, which again is not very common at the amateur cubesat scale. Leaks -- don't use pressurized gases or fluids; evaporation, just pick materials with < 1% total mass loss and less than 0.1% CVCM (i.e. Teflon insulation on wires instead of PVC).
As it turns out, amateur space isn't all that hard to do.
Generally speaking, microsatellites are in the range of 10 kg to 100 kg. What you are talking about are cubesats, which are generally nanosatellites (1 kg to 10 kg) and picosatellites (< 1 kg). As others have said, the AMSAT programme is a great starting point; next August come out to the Cubesat workshop and, if interested, hang out for the USU Small Satellite Conference; lots of industry, academia, and government representation. We host a booth every year, as do most relevant players in North America.
Yeah, you can have omnidirectional antenna coverage for both uplink and downlink. Our S-band transmitter is capable of 1 Mbps omnidirectional downlink at 650 km. This is the preferred method if you can close your link and data budgets because it makes the system vastly simpler and inherently fail safe (if it crashes and you lose attitude control, you can still talk to it). A secondary directional downlink may be reasonable if you have very high data requirements (e.g. streaming video or ultra high definition imagery), but generally speaking you never want to be in the situation where you can't talk to the spacecraft if it can't point at you, even in big space.
One tried and true anti-spin method utilized with CanSats (predecessors to CubeSats, see http://www.arliss.org/ is to attach a refrigerator magnet to one end of the satellite. The 'sat will flip 180 degrees as it passes over north and south poles, but remains otherwise in stable orientation. Sometimes simple is good :-)
--
A man is rich in direct proportion
to the number of things he can afford
to leave alone.
— Thoreau
Wow. Virtually every statement in this post is incorrect.
OP, get off Slashdot and go to amsat.org
Now. Good bye.
Since this is an AC, I thought I'd repost it. AMSAT is exactly the organization you want. They are a group of amateur radio operators who have successfully built several communications satellites. Even if you choose to work with another group (or start your own), their experiences will be most helpful.
Faster! Faster! Faster would be better!
That's just crazy talk! You need to lay off the drugs.
If I were God, wouldn't I protect my churches from acts of me?
You can slowly kill the spin by loading the satellite with magnetic torque rods. The rods cause the satellite to orient to the Earth's magnetic field. There are active and passive systems.
For coms that are effective in a spin, a couple of omni whips at right angles should do it. The basic unit is called a 1U Cubesat and it's 10cm x 10cm x 10cm container, but they can have mechanisms to pop out antennas as soon as they get out of the container. Some of the designs I've seen have pop-out arrangements of solar cells so they can have up to 500 cm2 of solar cell area and are made to orbit with them pointed away from the Earth. Cubesats can be stacked several in a launch container. (Like a six-pack.) There are 1U, 2U and 3U designs.
This year's Smallsat Conference is at Utah State University - Logan Utah, August 10 – 15, 2013
Smallsat
Having been on a team that has built and launched two cubesats, I consider myself somewhat of an expert in the area. I'll answer this question to the best of my knowledge, I've been to the cubesat conference for several years now (it's mostly academics but most of the launch companies are there.) The first couple of years as a student I would get all excited whenever companies like this would start up. I noticed quickly that the same company never came around to the conference more than a few years, why? Because they couldn't get the funding, a launch requires some where in the range of 10$ million. There are plenty of companies that start up and claim that they will launch a rocket with a 50-100 (or so cubesats) and that will cover there costs, the problem is they have to find that many people to fill the spots. No one has done that yet. Cubesats were designed as a containerized system to mitigate the testing and integration launch costs. Everything that goes to space has to be thoroughly tested, when you have to do this on a case by case basis, it takes a lot of time (=money). So if you already know your payload will fit in a 10cm x 10cm x 10cm (1U) and has a ~1kg weight then that saves a lot of testing. Another benefit of the container is NASA can slap them all over their rockets and launch 10's of them (currently) at a time. Since every rocket has tons of payload margin (you want to ensure your payload reaches space you size its mass several percent smaller than what the rocket can handle to ensure delivery) and some payloads are in the tons, throwing on a few cubsats won't really do a thing to your mass budget. Now NASA has a program for this: http://www.nasa.gov/mission_pages/smallsats/elana/index.html this has been successful. As far as launching your own, I wouldn't count on it in the near future. Launching a satellite is not trivial, you have to make sure its not going to break apart, or damage other payloads on the way out of its container. Look up ISBN: 047075012X . You have to make sure its not going to outgass because volatile compounds evaporate and can cause problems. You have to use materials that can withstand the rigors of space, atomic oxygen and radiation can be rough on most materials. Plus some materials like PVC will evaporate in a vacuum. Another problem is ensuring you have enough battery and solar power to support your payload. You have to make sure you payload will not shake apart on the way up (rockets are very very bumpy rides). The satellite should have an attributed and control system to make sure it can orient itself in the right direction (for your solar cells and radio). And last but not least is the radio and comm system. A ground station is needed and the appropriate radio frequencies used (if you want anything fast you have to get a license from the gov, this is very difficult). The satellite itself needs to have a good antenna (if you have any nulls in your antenna pattern then you won't be able to communicate with it when the null is pointed at you. Oh, and if you put a camera on it the NOAA has to know about it and approve of your data (really stupid, but that's the way the government is). Anyway I could go on for a long time... Building a satellite requires people from many different disciplines to pull it off. Unless you are going for insanely simple you would have to have a group of people to accomplish the task. If there is available access and launch costs come down I could see a few hobbyists groups pulling it off in 10 or so years if they can clear all of the governmental hoops. I won't believe any commercial venture claiming that they will launch cubesats (or tubesats http://interorbital.com/TubeSat_1.htm) until they actually do.
Yeah, you can have omnidirectional antenna coverage for both uplink and downlink. ... This is the preferred method if you can close your link and data budgets because it makes the system vastly simpler and inherently fail safe. ... A secondary directional downlink may be reasonable if you have very high data requirements (e.g. streaming video or ultra high definition imagery)
Most commercial and military satellites have a low-bandwidth omnidirectional uplink and downlink for control. USAF satellites used to have (and may still have) almost a complete separation between the "bus" and "payload" sides, with the "bus" side on omni antennas. At the ground end, the USAF had big steerable dishes at about six tracking stations around the world. The spacecraft was piloted through those. Command and control of most USAF satellites were run from the Blue Cube in Sunnyvale until that operation was moved to Falcon and Vandenberg AFBs.
Once the spacecraft was in the desired orbit and oriented, directional antennas were used by the payload to communicate with the payload user's control center. With directional antennas, smaller ground-side dishes could be used. The big steerable dishes were a scarce resource needed for multiple satellites, so tying them up for payload data like imagery was avoided.
Back in the early 1980s, one of the amateur radio satellites was incorrectly commanded to transmit on its own control receive frequency. This blocked the receiver from receiving further commands. To recover the satellite, the Stanford Dish was used. That 46 meter steerable radio telescope had, left over from old USAF work, a 3MW transmitter. The combination of a huge dish and a high powered transmitter allowed focusing enough power on the satellite to get through to the receiver and tell the satellite to change its transmit frequency. It took two tries (the first time the codes sent were wrong) but on the second try it worked.
That's because of law to protect the US space industry. To protect this industry against increasing revenue.
It's not a laughing matter.
In fact it's quite funny to see of this protective law has failed. You can go in Europe and ask european manufacter to build an ITAR-free satellite. A satellite without any US technology. Good for US business.
That's why I'd go for a TubeSat instead. Launch costs are within what mere mortals might spend on a hobby at $8kUS.
"When information is power, privacy is freedom" - Jah-Wren Ryel
To be fair, the "modest fee" is actually $40k, or in Average Joe language "about twice the cost of my car."
Or to me personally, "about four times the cost of all my cars combined."
"When information is power, privacy is freedom" - Jah-Wren Ryel
Professor James Cutler: http://aerospace.engin.umich.edu/people/faculty/cutler/index.html
RAX: http://rax.engin.umich.edu/
Prof. Cutler works on novel nanosats and how to streamline the nanosat process. He will probably push you off to his students, but I am sure they can point you in a better direction, what sort of commerical off the shelf (COTS) parts you can get and applicable restrictions.
GO BLUE!
Most CubeSats are launched through NASA's ELANA program. The launch is free if you win the ELANA lottery. Most people who enter lotteries don't win them.
All launches at the moment are rideshares with larger payloads. There have been attempts to develop dedicated launchers for small satellites but none have made it to the launching pad. NASA created the Nanosatellite Launch Challenge to encourage development of a nanosat launcher. It was canceled before the competition began.
At the moment, most CubeSats are built as educational projects to train engineering students. Launching them into space is kind of a bonus, if it happens.
The Defense Advanced Research Projects Agency (DARPA) is working on an airborne launch system for small payloads (ALASA). The Army is working on its own launcher called SWORDS. It is not certain if these efforts will be successful or if the launches will be available for civilian payloads, if they are successful.