Atmospheric Cloud Physics Laboratory Thermal Control

Abstract

This paper presents the development background and the present status of the Atmospheric Cloud Physics Laboratory (ACPL) thermal control capability. The ACPL, a Spacelab Payload, is currently in the initial flight hardware development phase for a first flight scheduled in June 1981. The ACPL is intended as a facility for conducting a wide variety of cloud microphysics experimentation under zero gravity conditions. The cloud chambers, which are key elements of the ACPL, have stringent thermal requirements. Thus the Expansion Chamber inner walls must be uniform to within ±0.1°C during both steady state and transient operation over a temperature range of +30 to −25°C. Design progression of the Expansion Chamber, from early inhouse NASA-MSFC concepts (including test results of a prototype chamber) to the thermal control concept currently under development at General Electric, is discussed.