ATS 2

Description

ATS 2 (Applications Technology Satellite) was a medium altitude, gravity-gradient-stabilized spacecraft designed to (1) test new concepts in spacecraft design, propulsion, and stabilization, (2) take high-quality cloudcover pictures, (3) provide in situ measurements of the aerospace environment, and (4) test improved communication systems. The cylindrically-shaped spacecraft measured 142 cm in diameter and 183 cm in length. The spacecraft structure consisted primarily of a corrugated thrust tube with honeycombed bulkheads secured to each end. Equipment components and payload were externally mounted on the outer surface of the thrust tube as well as on a structure that slid into the interior of the thrust tube. Electric power was provided by two solar arrays mounted on either end of the spacecraft's outer shell and by two rechargeable nickel-cadmium batteries. Extending radially outward from the side of the spacecraft were four 28.2-m, adjustable gravity-gradient booms. The spacecraft telemetry system consisted of four 2.1-W transmitters (two at 136.47 MHz and two at 137.35 MHz), in addition to a microwave communications experiment. The second stage of the ATS 2 launch vehicle failed to ignite, resulting in an unplanned elliptical orbit. Stresses induced by this orbit eventually induced spacecraft tumbling. In spite of these conditions, useful data were obtained from some of the experiments, most notably the cosmic-ray and particle experiments and the field detection experiments. The satellite reentered the atmosphere on September 2, 1969.