发射载具
Launch vehicles provide varying degrees of performance. For example, a satellite bound for Geostationary orbit (GEO) can either be directly inserted by the upper stage of the launch vehicle or launched to a geostationary transfer orbit (GTO). A direct insertion places greater demands on the launch vehicle, while GTO is more demanding of the spacecraft. Once in orbit, launch vehicle upper stages and satellites can have overlapping capabilities, although upper stages tend to have orbital lifetimes measured in hours or days while spacecraft can last decades.