ATS 6

Description

The primary objectives of ATS 6 (Applications Technology Satellite) were to erect in orbit a large high-gain steerable antenna structure capable of providing a good-quality TV signal to a ground-based receiver and to measure and evaluate the performance of such an antenna. A secondary objective was to demonstrate new concepts on space technology in the areas of aircraft control, laser communications, and visual and infrared mapping of the earth/atmosphere system. The spacecraft was also capable of (1) measuring radio frequency interference in shared frequency bands and propagation characteristics of millimeter waves, (2) performing spacecraft-to-spacecraft communication and tracking experiments, and (3) making particle and radiation measurements of the geosynchronous environment.

Configured somewhat like an open parasol, the ATS 6 spacecraft consisted of four major assemblies: (1) a 9.15-m-diameter dish antenna, (2) two solar cell paddles mounted at right angles to each other on opposite sides of an upper equipment module, (3) an earth-viewing equipment module (EVM) connected by a tubular mast to the upper equipment module, and (4) an attitude control and stabilization system. The EVM, in addition to housing the Earth-viewing experiments, provided support for the propulsion system and tanks, batteries, a multifrequency transponder, and the telemetry, command, and thermal control systems. The upper equipment module provided a platform for the space-viewing experiments. Inertia wheels were the prime means for torquing the spacecraft, with both hydrazine and ammonia multijet thruster systems included to provide the necessary torques for unloading the wheels. Also included was a small environment measurement package containing a MAG and several particle experiments.

The satellite was turned off on June 30, 1979 and boosted into a higher orbit. For detailed descriptions of the spacecraft and of the individual experiments, see the IEEE Trans. on Aerosp. Electron. Syst., v. AES-11, n. 6, November, 1975, and also the "ATS-6 Final Engineering Performance Report," NASA, RP-1080, Wash., D.C., November, 1981 (TRF B33477).