Design and Development of the Timed Spacecraft Solar Array 1999-01-2633

The Thermosphere, Ionosphere, Mesosphere, Energetics, and Dynamics (TIMED) spacecraft is the first science mission in the Solar Terrestrial Probe program sponsored by the NASA Office of Space Sciences and is being developed by the Johns Hopkins University, Applied Physics Laboratory (APL). TIMED will explore the Earth's Mesosphere and Lower Thermosphere/Ionosphere (MLTI) (60-180 km), the least understood and least explored region of our atmosphere. The TIMED spacecraft is a three axis stabilized, nadir pointing, low earth orbit scientific satellite with one side of the spacecraft always pointing away from the sun. The instruments' fields of view (FOV), pointing accuracy, jitter requirements, anti-sun pointing of one spacecraft side, and sun angle variations during the year place severe limitations on the design configuration of the solar array. This paper describes the design and engineering model test results for the TIMED solar array and deployment system.

Key words: LEO spacecraft, GaAs/Ge solar array, Free Deployment