GEO > Geosynchronous > Geostationary
[Source: NASA Space Science Data Center (NSSDC), http://nssdc.gsfc.nasa.gov/nmc/spacecraftDisplay.do?id=1977-048A
GOES 2 was a NASA-developed, NOAA-operated, geosynchronous, and operational ... spacecraft. The spin-stabilized spacecraft carried (1) a visible infrared spin-scan radiometer (VISSR) to provide high-quality day/night cloudcover data and to take radiance-derived temperatures of the earth/atmosphere system, (2) a meteorological data collection and transmission system to relay processed data from central weather facilities to APT-equipped regional stations and to collect and retransmit data from remotely located earth-based platforms, and (3) a space environment monitor (SEM) system to measure proton, electron, and solar X-ray fluxes and magnetic fields. The cylindrically shaped spacecraft measured 190.5 cm in diameter and 230 cm in length, exclusive of a magnetometer that extended an additional 83 cm beyond the cylinder shell. The primary structural members were a honeycombed equipment shelf and thrust tube. The VISSR telescope was mounted on the equipment shelf and viewed the earth through a special aperture in the side of the spacecraft. A support structure extended radially out from the thrust tube and was affixed to the solar panels, which formed the outer walls of the spacecraft and provided the primary source of electrical power. Located in the annulus-shaped space between the thrust tube and the solar panels were stationkeeping and dynamics control equipment, batteries, and most of the SEM equipment. Proper spacecraft attitude and spin rate (approximately 100 rpm) were maintained by two separate sets of jet thrusters mounted around the spacecraft equator and activated by ground command. The spacecraft used both UHF-band and S-band frequencies in its telemetry and command subsystem. A low-power VHF transponder provided telemetry and command during launch and then served as a backup for the primary subsystem once the spacecraft attained synchronous orbit. For more detailed information, see "The GOES/SMS User's Guide" (TRF B28599), available from NSSDC.