js7a+@andrew.cmu.edu (James Price Salsman) (10/06/89)
This "new plateau" stuff is okay, but here's what NASA has to offer: [From NASA plate TDRSS 3 / HqL-215] [The TDRS is] built by TRW, Redondo Beach Calif., and managed by Goddard Space Flight Center, Greenbelt, Md. The TDRS-C -- once deployed into its geosyncronous operational orbit 22,300 miles (35,800 km) [about 4 ground station round-trips per second] from Earth by STS 26 -- will be designated TDRS-2 and take up a position of 171 degrees west longitude. It will join TDRS-1, launched in 1983, now orbiting at 41 degrees west longitude. The TDRS-C will become part of an eventual three-satellite constellation to improve NASA's tracking of and communications with orbiting spacecraft, including the Space Shuttle. At 5,000 pounds (2260 kg), the TDRS satellites are the largest, most complex communications satellites ever built. Each measures more than 50 feet (15 m) from one tip of its solar array to the other. The TDRS system will provide satellite coverage from 85 to 100 percent of an orbit, depending on the user satellite orbital attitude, as contrasted with approximatly 15 percent with ground station coverage alone. Once deployed by the Shuttle, TDRS-C will be boosted into its geosynchronous orbit by a propulsion unit known as the Inertial Upper Stage, a rocket built by Boeing Aircraft Corporation and developed and managed by the US Air Force. Each of the TDRS can handle users with data rates up to 300 million bits per second. Assuming 8 bits of information per word, this is the equivalent of 300, 14-volume sets of encyclopedias every second. [Even if 8 bits per "word" were a reasonable assumption, that would mean 8929 "words" per "volume" of Encyclopedia. The Academic American Encyclopedia is orders of magnitude larger than that.]