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Another Amateur Radio Satellite
k4hg writes "Remember the US Naval Academy satellite with the measuring tape antennas?
Well, not only is it still alive after nearly four years in orbit (be sure to read the 2001 Slashdot articles to see who was right and wrong about it working at all!), but the latest satellite to come out of the same lab, called PCSat2, was installed Wednesday on the International Space Station. It is bolted to the space station on the P6 truss, but is otherwise independent, only benefiting from the high mass to drag ratio of the ISS to prolong orbital life. The satellite is alive and transmitting on amateur radio frequencies, I could hear it on a marginal elevation in the Florida Keys. When it come in range of a ground station with better coverage, the data will be viewable here in real time. This new system is in addition to the amateur radio station already operational on the ISS.
And yes, they used tape measure antennas again, you could see them deploy on Nasa TV!"
The thing may be cheap to build, but you can not just throw it up there like a kite, it needs a rocket to get it into orbit. the price does not reflect this cost.
To Hell with the Queen of England!
Freefall research. Lots of processes give totally unexpected results without gravity. Some of them can be simulated in ballistic flight, but it lasts at most a few minutes. You can't examine gravity-less growth of plants, formation of crystals, diffusion of liquids and all kinds of processes that simply take time. Things that depend on gravity start often to behave in completely unexpected ways when the gravity is not present. We often have no idea what kind of profit would that give us, but it's like exploring unknown land - you have a good chance of finding something valuable, even if you don't know up front what would that be. :) Dirt cheap vaccuum of good quality (think removing dust/particles/contaminations from ultra-high precision manufacturing, just a great cleanroom "outdoors"). Global travel - several hours to get above any latitude, for free (think orbital observation). Unfiltered cosmic rays. (Bad for humans, but research could greatly benefit, finding particles that simply don't filter through the atmosphere. Also, lots of solar power). No clouds, air, lights, vibrations - all that is needed for good astronomy.
Long-term freefall is impossible to simulate on Earth and that's one essential condition of research, but there are others that help a lot. Dirt cheap cryo temperatures. (think superconductors - just put the CPU outdoors and in a shadow
There's a lot of profits from this location. Now, whether they are utilised or not is a different matter...
Just a theoretical idea: Orbital microchip factory. Partially purified resources brought from Earth. Then final purification on the orbit. Waste in large packages mapped as "known space junk" put on a decaying orbit to burn in the atmosphere a few years later. Storage: Open space, possibly shielded from the sun by a big "sail". Purification: No worries about gravity mixing the fluids in transport, possiblity to hang charged pieces of material "levitating" without being touched (=contaminated) by any handling devices, no air/dust contamination (easy to purify the vaccuum by charging and then dragging away all the particles entering the area), then all the processes without any medium to transfer any kinds of vibrations, get optical beams out of focus, no forces on lenses that could change their shape, cheap to achieve dynamic liquid lenses for advanced optics etc. The devices manufactured could be of way higher quality than on Earth. Orders of magnitude in miniaturisation, less manufacturing errors, perfect manufacturing conditions really cheap. Just transport, supply, servicing would cost. And of course intruder risk: Space junk, micrometeorites. But these would be just a calculated risk. Facilities could be located sparsely enough that damage to one would not break any other - the line would just switch to a redundant backup and the broken facility would be replaced with next transport. And a single lander filled with a million of 30 Watt 20GHz 256-core CPUs would quite likely be enough to finance the whole investment.
Anagram("United States of America") == "Dine out, taste a Mac, fries"
The very first amateur radio satelite, OSCAR-I used tape antennas back in 1961. The antennas were made out of steel measuring tapes because they could be folded back against the satelite during launch and would spring into position as the satelite separated from the rocket. The tapes are 1/4 wavelength long, which at 2 meters (145 mhz) is about 19" long. Most satelites operate at higher frequencies, though the amateur 10 meter band at 28mhz is also available for satelite use. You do the math to see how long those antennas would be....(75/frequency in mhz = length in meters for a 1/4 wave antenna)
Get your license, it requires very little effort or cost and the toys it lets you use can be pretty cool. There's lots of variety to amateur radio so I guess you go with whatever floats your boat. There are people doing EME (reflecting signals off the moon). Hearing a signal that has travelled almost half million miles may sound more impressive than a hundred miles. There are others that bounce signals off the ionisation trails of meteors. I was at a local amateur radio emergency services meeting earlier this week and we were broadcasting a TV signal from a camcorder. I have more prosaic interests: mainly HF but doing the public service stuff is also pretty good - you get great vantage points for events.
Because it's a VHF satellite, and on the Earth, VHF communications are limited to line of sight, and a couple of hundred miles is considered DX (a long-distance communication) for VHF, usually only possible with a) tropospheric ducting (weird form of radio propagation where temperature inversions bend radio waves) 2) bouncing the signal off a meteor trail (woo, ionization!) or 3) using a satellite... or a really tall directional antenna which can peek over the curvature of the Earth. What you're thinking of of routine conversations between Pensacola and Kew West are HF communications which operate at a different frequency and get around the line-of-sight problem by bouncing off ionized layers of atmosphere, specifially the ionosphere, which VHF signals go right through. So.. different communications band, different technical challenge, plus... it's SPACE! If you can talk to this satellite, you can also talk to the astronauts aboard the ISS who are quite often hams themselves http://www.arrl.org/ARISS/arissfaq.html