Abstract
Multilayer insulation systems that have robust operational characteristics have long
been a goal of many research projects. Such thermal insulation systems may need to offer
some degree of structural support and/or mechanical integrity during loss of vacuum
scenarios while continuing to provide insulative value to the vessel. Aerogel-based
composite blankets can be the best insulation materials in ambient pressure environments;
in high vacuum, the thermal performance of aerogel improves by about one order of
magnitude. Standard multilayer insulation (MLI) is typically 50% worse at ambient
pressure and at soft vacuum, but as much as two or three orders of magnitude better at high
vacuum. Different combinations of aerogel blanket and multilayer insulation materials have
been tested at the Cryogenics Test Laboratory of NASA Kennedy Space Center. Analysis
performed at Oak Ridge National Laboratory showed an importance to the relative location
of the MLI and aerogel blankets. Apparent thermal conductivity testing under cryogenicvacuum
conditions was performed to verify the analytical conclusion. Tests results are
shown to be in agreement with the analysis which indicated that the best performance is
obtained with aerogel layers located in the middle of the blanket insulation system.