Multilayer insulation considerations for large propellant tanks

• Overview of past cryogenic insulation tests applicable to large tanks.
• Provide prediction methods for cryogenic insulation performance.
• Provide recommendations for designing insulations and further development tests.

Multilayer insulation (MLI) systems for cryogenic instrument Dewars have demonstrated very high thermal performance in ground and orbit. Ground tests of insulation systems on propellant storage size tanks have shown performance and repeatability issues. This paper presents a summary of studies for National Aeronautics and Space Administration (NASA) focused on MLI systems on the larger Tankage. The sensitivity of boil off to MLI thermal conductivity is presented. The effect of compressions, assembly joints and MLI parameters are presented. A novel large tank simulator approach for MLI testing is presented along with recommendations for maturation of the MLI technology.