Wrapped-IMLI: Thermal Insulation for Cryogenic Feed Lines

NASA Exploration vehicles require improved technologies for passive thermal insulation for zero boil-off of cryopropellants during extended LEO and lunar surface missions. Vehicles such as the Earth Departure Stage and Orion must be capable of multi-day orbital operation with minimal cryopropellant loss, and the Altair Lunar Lander must have minimal cryopropellant loss over a six month mission on the lunar surface. Quest Product Development, teaming with Ball Aerospace, proposes an innovative advanced insulation system, Wrapped-IMLI, which could provide high performance thermal insulation for cryogenic feed lines. Wrapped-IMLI is a multi-layer system using proprietary micromolded polymer spacers to precisely control layer spacing and reduce inter-layer heat conduction. IMLI versions of this concept, for cryotanks, have been proven with a measured thermal conductivity of 8.8*10-5 W/m-K, 37% lower heat leak than conventional MLI. Preliminary research indicates W-IMLI could provide excellent thermal insulation for cryo-feed lines. Propellant boil-off losses are directly influenced by the MLI, which is the biggest heat leak in cryogenic propellant storage. It is known that MLI insulation for cryogenic propellant feed lines is much less effective than MLI for tank insulation. A Ball Defense Program study indicates the heat leak through spiral-wrapped MLI into lines is up to 10 times worse per area than tank MLI. Better insulation for cryo-feed lines is an important enabling technology for NASA Exploration vehicles. In this Phase I project we would model, conduct a trade study on thermal requirements for NASA spacecraft cryogenic feed lines, design W-IMLI, fabricate a prototype and measure thermal performance.