6.5-M Diameter Large Thermal Vacuum Chamber for Satellite Payload Testing

6.5-meter Diameter Large Thermal Vacuum Chamber is a versatile space simulation facility designed and configured to conduct a variety of thermal vacuum qualification tests on satellite payloads. Completed in 2018, the facility layout has been designed to streamline and to simplify test preparation and testing activities. The chamber has a cylindrical configuration and is housed inside a 22-m (72-ft) x 45-m (148-ft) large cleanroom (ISO Class 8) with a usable volume of approximately 200 m 3 (6.5-m diameter x 7.5-m length chamber) or 7056 cu. ft (21-ft diameter x 25-ft length chamber). The system can reach approximately a 5 x 10 -6 mbar vacuum level within 8 hours and has the capability to attain temperature extremes from 100 K to 433 K on its thermal shrouds. The thermal system can handle an approximately 100-kW heat load with 10 K homogeneity at 173 K on the thermal shrouds with a cluster of thermal conditioning units. The facility has 256 dedicated T-type thermocouple channels for temperature monitoring of the payload and systems, such as residual gas analyzers, quartz crystal microbalances, and atmospheric gas analyzers for chamber cleanliness monitoring. The facility also has unique features, such as a precise payload positioning system, a thermal cycling box, a flexi shroud for optimizing the internal chamber test volume, a four-rail system for GSE (i.e., ground support equipment), internal and external work platforms, a fresh air recirculation system, a closed-circuit television monitoring system, and so forth. The facility is equipped with significant liquid nitrogen storage (approximately 400,000 L [105,700 gal.]) and a distribution system (i.e., approximately 2200 m [7200 ft] of vacuum-jacketed super-insulated lines). The complete system is realized with a state-of-the-art control and data acquisition system, and has built-in hot redundancies for critical hardware. It uses a PC-PLC-SCADA-based electrical, instrumentation, control, and monitoring system (i.e., a personal-computer-based, programmable-logic-controller-and-supervisory-control-and-data-acquisition-supported EICMS) for control (operational interface and process monitoring) and elaborate data acquisition. Its unique system configuration is amenable to future augmentations, as well. This paper provides a complete overview of the facility and presents system configuration details, design considerations, realization aspects, and acceptance test results.