schnor said:
Yes, there is a 'perfect' geosynchronous belt at about 34,000km, but you can achieve 'non-perfect' geosynchronous orbit (pfft you lot are nit pickers
) at heights above and below, which is why you have the problem of having to cram in every satellite into the relatively small 'perfect belt'.
That fact is why I judged the object to have been in the belt for a few years, and it's orbit is now decaying - getting closer to atmospheric burn up each day.
Not convinced that you're on about a geo-synchronous orbit.
A geo-synchronous orbit is one in which the orbital period is equal to one siderial day. (i.e. a smidgeon short of the normal solar day of 24 hours.) If it is a circular orbit, then you end off with a satellite ground track looking like a figure of eight. (The greater the inclination of the orbital plane, the larger the figure of eight.)
A geo-stationary orbit, is a special case of a geo-synchronous orbit, in that the orbit is now equatorial (i.e. has an inclination of zero,) and in the direction of rotation of the earth. This means that the satellite appears to hover over one spot on the ground.
Typically a satellite in geo-stationary orbit has to expend fuel in order to maintain its position, as perturbations on it due to the moon, sun, etc. cause it to get messed up and start doing a figure of eight, as well as drifting around in latitude. (The corrections to its natural behaviour are known as "north south station keeping", and "east west station keeping.")
For a circular geo-synch, or geo-stat, orbit, the altitude is the same, and is approx. 36000 km. The shuttle, on the other hand, (except when it has Bruce Willis on board
) only gets up to LEO (Low Earth Orbit) which for the shuttle is an altitude typically of ~500 km (depending on the mission), and has an orbital period of ~90 mins (ballpark) so it is a long way from being anything like geo-synchronous or geo-stationary.
As regards the lifetime of the beasts in GEO, they're going to be around up there (barring collision with UFOs, etc.
) for an extremely long time, so the object in the video is unlikely to be something that is decaying out of GEO. (I suspect that you may confusing geo-syncronous with sun-synchronous, where the orbit is designed such that the plane of the orbit rotates exactly once a year. This has the useful property that the satellite always crosses the equator at the local solar time.)
Coming back to the object in the video, it clearly lies between the camera (on the shuttle) and the earth, so it is at a lower altitude. The shuttle appears to be travelling with it's rear end pointing in the direction of motion. (The shuttle always launches in the direction of the earths rotation, and is travelling faster than the earth rotates.)
If the object were travelling in a circular orbit more or less parallel to the shuttle, and in the same direction, then you would expect it to overtake the shuttle. As the opposite is happening, then we have to assume either:
a) The object is travelling in a retrograde (i.e opposite direction to the rotation of the earth) direction, and hence the "closing speed with the shuttle is ~15 km/s, or
b) it is a non-orbital object (e.g. meteor, or other) or,
c) The movie loop is playing in reverse.
Note that option a) is unlikely as people don't normally launch into those kinds of orbits. (You usually need a very good reason, as they require a lot more energy to get things up there.)
Option b) isn't out of the question, though you might wonder why the sighting of a meteor from space never made it to at least the pages of New Scientist.
Option c) is an interesting one. As has been pointed out, there is very little information to go along with this movie. We don't know were, when, which mission, etc. It isn't inconceivable that someone has reversed a movie to make it look more interesting. (Note that if that is the case, then it is possible that the object is some junk/ice/etc. that has detached from the front end of the shuttle.)
Just some jumbled ramblings...
