AMTT: Aerospace materials technology testhouse

• Research unit: EU RFP
• Project number: 02.0082-1

Key words (English)

Multilayer insulation (mli)

Alternative project number (English)

EU project number: HPRI-CT-1999-00024

Research programs (English)

EU-programme: 5. Frame Research Programme - 4.2 Agriculture and agroindustry

Short description (English)

See abstract

Abstract (English)

Multilayer insulation (MLI) is the material of choice to protect spacecraft from radiative losses or extreme heat.The theory behind MLI is based on modelling a series of infinite plates and determining an equivalent (linearized) conductivity, so called equivalent emissivity. The problem is that this predicted emissivity correlates well with flat samples of the materials but not at all with the observed values when applied to real surfaces such as an entire satellite or any of its substructures. The errors range between a decade and a factor 100. Furthermore if this emissivity is plotted against temperature the real surface shows a drop with increasing temperature, whereas the test coupons show an increase. This is extreme enough that MLI design has become more an art based on prior performance than a science which would allow weight and performance optimisation. Objective of the project is to generate a correlation for multilayer insulation that would allow prediction of performance in coating real surfaces and hence an optimisation.
The program was based on using four different types of MLI in differing configurations and required the measurement of emissivity in a vacuum chamber at space environment temperatures: -150°C to 200°C. Furthermore a correlation with space structures, in this case a Louver breadboard, was to be measured.

References in databases (English)

Swiss Database: Euro-DB of the
State Secretariat for Education and Research
Hallwylstrasse 4
CH-3003 Berne, Switzerland
Tel. [phone]
Swiss Project-Number: 02.0082-1