Sonoma State students build, deploy tiny satellite
Orbiting about 400 miles over your head is a tiny box that could revolutionize the way we think about satellites.
Designed and built in part by students at Sonoma State University, the "T-LogoQube" may be the smallest functioning satellite ever put in space; it's certainly among the cheapest. It is also, in all probability, the only satellite ever launched that can be reprogrammed in flight, opening a new era of flexibility for hardware in orbit.
"The software is more sophisticated than any satellite I've ever worked on, even the most expensive ones," said retired UC Berkeley research physicist Garrett Jernigan, who helped create the SSU program.
The satellite is tiny, just 5-by-5-by-15 centimeters, or about the size of a TV remote control. Inside is a tiny radio and a sensor that reads the earth's magnetic field.
The satellite passes over Sonoma County twice a day, around noon and midnight, giving the students two chances a day to communicate with it. The satellite sends data about its position and condition; the students send up instructions to pivot, spin, or do other basic tricks by using coils of wire that react to the magnetic field and push the satellite around in orbit.
That may not seem like much, but the fact that it was built in a matter of months by undergraduate students using off-the-shelf electronics, all for a few thousand dollars, is revolutionary, said Professor Lynn Cominsky, chair of the SSU Department of Physics and Astronomy.
"We can talk to it and it does things … that's the kind of capability that you usually have on a $100 million satellite," said Cominsky, who is married to Jernigan.
Now that the students know how to do such a thing, she said, it opens up the possibility of launching tiny satellites carrying instruments that would generate useful scientific data, such as X-ray or gamma ray sensors searching for distant stars and other celestial objects, a personal area of research for Cominsky.
The steadily decreasing size and price of electronics opens up orbital sciences to small-scale researchers the way technology opened up radio astronomy and other ground-based research in the 1980s, she said.
Still, it's no small thing to get a satellite into orbit. Most of all, of course, you need a rocket, which SSU does not have. The chance came up when Professor Bob Twiggs of Morehouse State University in Kentucky, the inventor of a new generation of small satellites known as "CubeSats," offered Jernigan and Cominsky a spot in a much larger Italian satellite that was going to release a swarm of mini-satellites upon reaching orbit.
That Italian vehicle blasted off atop a Russian rocket on Nov. 21 and, shortly thereafter, the SSU satellite settled into a comfortable polar orbit about 634 km, or about 394 miles, above the Earth, where it should remain for many years.
The tiny satellite itself was a co-production of Cominsky's SSU students and Twiggs' Morehouse students. The students in Kentucky built the aluminum frame and tiny solar panels, while the SSU students designed and built the electronics inside and the trigger mechanism to deploy the solar panels once in orbit.
The assembled satellite was tested back at Morehouse, which is home to an advanced aerospace lab, built in 2009, a facility SSU cannot match.