SeaWinds scatterometer instrument thermal control system

The Ku-band SeaWinds scatterometer, developed for NASA's Jet Propulsion Laboratory, is part of the Earth Observing System which will measure global environmental changes. Scheduled for launch on the Japanese Advanced Earth Observing Satellite (ADEOS) in the year 2000, the instrument measures wind data over the Earth's ice-free oceans every day. The development of the 110 watt peak power radar involved many design trade-offs including the temperature performance. A passive thermal control system, providing a narrow band temperature response in all orbit environments, was necessary to maintain stable radar calibration over a three-year operating life. This paper describes the evolution of the thermal control system design and test validation for the scatterometer electronics subassembly (SES).