女生小视频

Technofile : Solar propulsion

An experimental spacecraft that will use solar energy and can raise a
satellite from a low Earth orbit to a geosynchronous orbit is being built by
Boeing. The Seattle-based aerospace company won a $48 million contract
from the US Air Force last month to build a Solar Orbit Transfer Vehicle, to be
launched in October 2001. 鈥淭he beauty of it,鈥� says Boeing programme manager Ed
Cady, is that the solar unit remains attached to the craft and 鈥渃an power the
satellite throughout its orbital life鈥�. The unit produces much less power than a
rocket, and it will take 30 days to lift the satellite more than 30 000
kilometres into its final orbit.