Description: Current cryogenic insulation materials suffer from various drawbacks including high cost and weight, lack of structural or load-bearing capability, fabrication complexity, and property anisotropy. A need clearly exists for lightweight thermal insulation that is isotropic, structurally capable, and exhibits improved thermal performance relative to current materials and structures. Aerogels have been investigated as an insulation material for cryogenic tanks due to their ultralow thermal conductivity and density, but they suffer from poor structural integrity and require expensive processing. Open-cell foam structures have also been researched, but suffer from the requirement for high vacuum in order to perform adequately. In previous work for NASA and DoD involving lightweight structural insulation for high temperature engine and airframe applications, Ultramet developed and demonstrated lightweight open-cell foam insulators composed of a carbon or ceramic structural foam skeleton filled with a low-cost, nanoscale aerogel insulator. The potential exists to adapt and optimize aerogel-filled structural foam for the cryogenic insulation application, thereby taking advantage of the thermal and mechanical benefits of each component while also offering low cost and manufacturability in complex shapes. In this project, Ultramet will team with Alliant Techsystems (ATK), a leading aerospace firm, to demonstrate the initial feasibility of the innovative cryogenic insulation to meet NASA requirements.

Benefits: Advanced cryogenic insulation will find extensive commercial application as cryogenic liquids (nitrogen, oxygen, argon, carbon dioxide, and liquefied natural gas) must be stored, handled, and transferred in support of the food, transportation, energy, and medical industries. To minimize heat leaks into storage tanks and transfer lines, high-performance, economical materials are needed to provide high levels of thermal isolation and minimize evaporation losses.

The potential application of this technology as a lightweight, ambient pressure structural insulator for cryogenic propellant tanks and lines may prove an enabling technology for future NASA lunar and planetary missions. Passive thermal control is required for zero-boiloff storage of cryogens for both long term (>200 days for liquid oxygen and hydrogen) on the lunar surface and short term (14 days) on orbit. The technology will also support current and future development of cryogenic oxygen/methane rocket engines at ATK. The proposed aerogel-filled structural foam cryogenic insulation will offer improved thermal performance over current materials, with the added benefits of reduced weight and fabrication and installation costs.