Effects of the thermal environment on the thermal control system of AMS

Abstract

This paper presents an overview of the AMS thermal control system and its thermal environment on the ISS. We give examples of analysis and correlation of space environmental impacting on the thermal control system of AMS. The most critical factors that affect the thermal environment to AMS are beta angle, attitude of ISS, ISS solar array and ISS radiator positions. The design of a special sandwich structure with embedded heat pipes provides the radiator with higher heat transfer ability for electronics and power crates, and it provides a large heat retaining capacity to balance the frequent changes of the space environment temperatures as well. In cold cases, the thermostatically controlled heaters are working actively to protect AMS. However, sometimes, because of ISS special operations plus extreme beta angle condition, AMS needs to request NASA to adjust the ISS configuration for thermal control. The AMS thermal control system is reliable and stable, which has been verified by its operation on the ISS for more than three years. All the detectors operate normally, the electronics and crates work within their specific temperature limits.