A Small Satellite Bus Designed for Low Earth Orbiting Experiments

The concept of a small satellite bus, designed to support a variety of low earth orbit payloads, has led to the detailed design of such a bus and its launch vehicle adapter. The basic bus, which weighs approximately 170 Ibs, is sized for launch on either Pegasus or Scout. It provides three axis stabilization (gravity gradient boom plus constant speed momentum wheel), solar power (40 watts minimum after 1 year in polar orbit), an S-band TM transmitter (1 watt output) and command receiver, a microprocessor-controlled telemetry encoder/formatter (usable at data rates up to 300 kbps), a command system providing logic level, digital word and relay outputs, a NASA-standard tape recorder (up to 700 Mbits of storage), and a simple thermal blanket/thermostatic heater temperature control system. Minimal redundancy is employed, consistent with the missions visualized for small experimental satellites.