GPS Test Successful From Outer Space
An anonymous reader writes: "AMSAT reports that the GPS experiment
on the international amateur radio spacecraft AO-40 has undergone successful testing." A note on the site reads in part: "This experiment supplied and sponsored by NASA, is to determine if it is possible to get positional data outside of the GPS ring of satellites.
There are two GPS receivers on AO-40, the A receiver for receiving signals around apogee and the B receiver for signal reception around perigee. ... A signal on the apogee receiver from about 52 Thousand Kilometres out with good signal levels has been received, further data is being gathered and those
downloaded so far are being analysed. If this experiment goes the way I expect, it will revolutionise the way we use GPS in Space. Many future HEO spacecraft will
be able to take advantage of GPS for autonomous navigation
and stationkeeping." This is one of the most interesting applications of GPS technology I've heard about -- nice way to reuse what was intended as a terrestrial navigation aid.
This opens up so many possibilities! Like the article mentioned, satellite station keeping for one. Also, we would know exactly where they were (well, down to a few dozen meters at least) for avoidane and things like that.
Also, so much is said about the problems of space debris. GPS recievers can be small, small enough to attach to debris. Yes, placing it on every little thing could suck, but on the larger things that pose a real hazard. I know there is a project to map the sky's debris, forgot the link. Now, astronauts could know in real time where this stuff is.
Using this for navigation might not work now. As far out as you are, the satellites are really close together, and any errors you see now are going to be much larger. But, we could place GPS satellites orbiting other bodies to use for solar system navigation. LIke i said, lots of possibilites.
http://www.google.com/search?hl=en&lr=&ie=UTF-8&o