'Zombie' Satellite Returns To Life 98
realperseus writes "The American telecommunications satellite Galaxy 15 has been brought under control after spending most of the year traversing the sky and wreaking havoc upon its neighbors. The satellite is currently at 98.5 degrees west longitude (from 133 west). An emergency patch was successfully uploaded, ensuring that the conditions which caused it to 'go rogue' will not occur again. Once diagnosis and testing have been completed, Intelsat plans to move the satellite back to 133 west."
Re:Technically... (Score:3, Interesting)
Amsat-OSCAR 7 (Score:5, Interesting)
It's worth comparing it with the venerable AO-7 satellite, which was launched in 1974 and eventually "died" when its battery failed dead short in 1981. A little over ten years later, the failed battery failed again, this time going *open* circuit and allowing the satellite to run entirely off its solar panels. So, while the satellite is illuminated by the Sun it works fairly reliably. You need to keep the power down, because it has a linear transponder so the more power you put in the more comes out - until you exceed the tiny amount produced by the solar cells. It works, though, and people communicate across the world on it every day.
Just like that? (Score:4, Interesting)
Re:Triaxiality (Score:2, Interesting)
Hmm. I would have thought that the ellipsoid shape of the Earth would have less influence on an equatorial orbit than the changing relationship of that orbit to the Earth - Moon barycenter [astronomycafe.net].
Relative to our frame of reference on the surface of the Earth, a geosynchronous orbit would of course be stationary above someone's head, while the barycenter would be rushing around some 2,000 km below our feet at an angular speed of 15 degrees/hr, wandering more than 30 degrees north and south of the equator on a seasonal basis. Since all Earth satellites orbit around the barycenter rather than the geometric center of the Earth, you would expect the Earth's dense core to be the primary cause of orbital perturbations.
But what do I know? Any astronomers or rocket scientists want to jump in here?
As an aside, the barycenter does its dance in the bottom of the mantle, just a little bit above the liquid outer core ( here is a quick depth guide [wikipedia.org]. My understanding is that to date, geologists are not trained to look at possible astronomy influences when building models of the Earth's interior, and astronomers do not consider the inside of the Earth to be in their province. So perhaps something very interesting is going on in this region that has so far been overlooked. Or perhaps the barycenter dancing on the margins of the liquid core is just one of those weird coincidences that only a whacko would consider. You know, like continental drift.
It would be really nice to hear from some persons who know a thing or two about this kind of stuff.