Thermodynamic performance predictions for the low temperature micro-gravity physics facility

Abstract

The Low Temperature Micro-gravity Physics Facility (LTMPF) designed by Ball Aerospace & Technologies Corp. contains a 180-l superfluid helium dewar for conducting fundamental physics experiments. The dewar and ancillary experiment electronics will be located on the Japanese experiment module-exposed facility (JEM-EF), a module of the International Space Station. The helium is expected to deplete over approximately 5 months, after which the facility will be returned for new experiments, refurbished, refilled and relaunched on a projected 22-month cycle time. Because of the JEM-EF envelope constraints, the dewar has a unique ob-round cross section. The strut-mounted helium tank has provisions to accommodate two separate experiments, one at each end of the tank. Until the cryostat is constructed and tested, assessments of cryostat performance must be accomplished with analytic models. This paper documents the predicted thermal/thermodynamic performance of the cryostat from final launch top-off operations, through post-launch transients, to steady-state on-orbit performance.