DMSP 5D-1/F2
type: Concept
in scheme: platforms
definition: [Source: National Space Science Data Center, http://nssdc.gsfc.nasa.gov/nmc/spacecraftDisplay.do?id=1977-044A ] DMSP 5D-1/F2 was one of a series of meteorological satellites developed and operated by the Air Force under the Defense Meteorological Satellite Program (DMSP). This program, previously known as DAPP (Data Acquisition and Processing Program), was classified until March 1973. The objectives of this program were to provide global visual and infrared cloud cover data and specialized environmental data to support Department of Defense requirements. Operationally, the program consisted of two satellites in planned 830-km sun-synchronous polar orbits, with the ascending node of one satellite in early morning and the other at local noon. The 5.4-m long spacecraft was separated into four sections: (1) a precision mounting platform (PMP) for sensors and equipment requiring precise alignment, (2) an equipment support module (ESM) containing the electronics, reaction wheels, and some meteorological sensors, (3) a reaction control equipment (RCE) support structure (that has the third-stage motor, hydrazine reaction control system) which supports (4) a 9.29 sq mm solar cell panel. The spacecraft stabilization was controlled by a combination flywheel and magnetic control coil system so sensors could be maintained in the desired `earth-looking' mode. One feature was the precision-pointing accuracy of the primary imager to 0.01 deg provided by a star sensor and an updated ephemeris navigation system. This allowed automatic geographical mapping of the digital imagery to the nearest picture element. The operational line scan system (OLS) built by Westinghouse, was the primary data acquisition system that provided real-time or stored, multi-orbit, day-and-night visual and infrared imagery at 1/3-nautical-mile resolution for all major land masses, 1-1/2-nautical-mile resolution for complete global coverage, and provided with this data calibration, timing, and other auxiliary …

Defense Meteorological Satellite Program (DMSP)
type: Concept