Nimbus
type: Concept

Nimbus-3
type: Concept
change note: 2015-05-12 12:53:55.0 [saritz] update PrefLabel (Nimbus-3);
in scheme: platforms
definition: Nimbus-3 was launched in April 1969 and was the third in a series of second-generation meteorological research-and-development satellites that was designed to serve as a stabilized, earth-oriented platform for the testing of advanced meteorological sensor systems and for collecting meteorological data. The polar-orbiting spacecraft consisted of three major elements: (1) a sensory ring, (2) solar paddles, and (3) the control system housing. The solar paddles and the control system housing were connected to the sensory ring by a truss structure, giving the satellite the appearance of an ocean buoy. Nimbus-3 was nearly 3.7 m tall, 1.5 m in diameter at the base, and about 3 m across with solar paddles extended. The torus-shaped sensory ring, which formed the satellite base, housed the electronics equipment and battery modules. The lower surface of the torus ring provided mounting space for sensors and telemetry antennas. An H-frame structure mounted within the center of the torus provided support for the larger experiments and tape recorders. Mounted on the control system housing, which was located on top of the spacecraft, were sun sensors, horizon scanners, gas nozzles for attitude control, and a command antenna. Use of the attitude control subsystem (ACS) permitted the spacecraft's orientation to be controlled to within plus or minus 1 degree for all three axes (pitch, roll, and yaw). Primary experiments consisted of a satellite infrared spectrometer (SIRS) for determining the vertical temperature profiles of the atmosphere, an infrared interferometer spectrometer (IRIS) for measuring the emission spectra of the earth-atmosphere system, both high- and medium-resolution infrared radiometers (HRIR and MRIR) for yielding information on the distribution and intensity of infrared radiation emitted and reflected by the earth and its atmosphere, monitor of ultraviolet solar energy (MUSE) for detecting solar UV radiation, image dissector camera system for providing daytime c…