|
The fun one is called Molniya. Its tilted like 60 degrees from the equator and elliptical. Kinda difficult to launch geo from latitudes far from the equator (takes too much fuel). That and another problem with Geostationary is even at that distance from the earth, the poles look real flattened and nothing very north or south gets a good signal (alot of Russia, Sweden, Finland, etc).
as for the spy satellites, they are likely highly elliptical. They swoop down close (travelling much faster than when they are far away). The benefit is that even though people may THINK they know when it will pass, the satellite could technically make a small burn at the apogee and offset the time of overpass (would still be daylight though).
|