Experimental investigation on combination of vapor cooled shield (VCS) and multilayer insulation (MLI) for cryogenic application

Abstract

The long-term storage of cryogenic propellants on orbit under thermal and pressure control is a promising enabling technology for future space exploration. The combination of vapor cooled shield (VCS) and multilayer insulation (MLI) is considered as an effective passive thermal control method for such missions. To experimentally investigate the thermal insulation performance of VCS and MLI combination (MLI/VCS), a cryogen boil-off calorimeter system has been designed and fabricated. It is capable of measuring the heat flux through the VCS and MLI combination, as well as the temperature profiles both on the VCS and inside the MLI. The insulation effectiveness of MLI/VCS is evaluated with liquid nitrogen as the simulated cryogen in the warm-boundary temperature range from 200 K to 350 K. For the warm boundary temperature of 350K case, the insulation performance comparison between MLI/VCS and MLI only is conducted. In addition, the heat transfer behaviour within the insulation combination is discussed in detail.