USI - Phase 2: Non-flammable Super-Insulation (USI)

Based on the multi-layer insulation technology for spacecraft, this technology transfer project about non-flammable super-insulation focuses on the development of a novel, inert multi-layer thermal insulation, which satisfies the applicable requirements and standards for cryogenic vessels used for storage and transport of liquefied technical gases such as He, Ar, N 2 and O 2 , with respect to oxygen compatibility.

Short Description

The cornerstones for the project were prepared in phase 1. Using the now well defined requirement specifications for different applications and considering the necessary adaptations to the needs of major cryogenic device suppliers, USI Phase 2 featured an ambitious test program.

The scientific partners, the Austrian Research Institute for Chemistry and Technology (ofi) and the Institute of Applied Physics of the Vienna University of Technology, contributed their strength in the fields of chemistry, physics and the theory of combustion, extinction and fire dynamics.

New ultra-light spacer materials were employed to reduce the influence of absorption between reflective foil layers in the spacer material and thus increase the insulation efficiency. Specialized glass fiber materials without organic content were identified and used. All new materials were tested with calorimeter measurements for insulation efficiency and with drop tests in liquid oxygen for oxygen compatibility and non-flammability according to international standards.

Gas flows through narrow gaps filled with novel spacer material were measured and the possible impact of residual gas in super- insulation packages was determined.

Alternatives to non-flammable super-insulation were investigated:

For surfaces at very low temperatures (e.g. 4 Kelvin at helium cryostat surfaces), a new and more robust laminate material was successfully developed and tested.

Simulations using generic algorithms for optimization of the mechanical spring elements employed in whole-metal-insulation concepts improved the theoretical performance considerably.

Project Partners


RUAG Space GmbH - Helga Lichtenegger


  • Vienna University of Technology, Institute of Applied Physics - Herbert Störi
  • Austrian Research Institute for Chemistry and Technology (ofi) - Martin Englisch

Contact Address

RUAG Space GmbH
Helga Lichtenegger
Stachegasse 16
A-1120 Vienna