An ARC-Free Thermal Blanket for Spacecraft Use

Thermal considerations require the use of dielectric materials, such as Kapton and Teflon on the outside of a spacecraft. These materials, when subjected to energetic electrons, are charged to several thousand volts. Consequent discharges present a problem to the smooth operation of the spacecraft and also cause degradation of the material and electronic components, thus limiting the useful lifetime of the spacecraft. This paper presents a new low mass, low cost multilayer thermal blanket (*) utilising Kapton on the outside which limits charge build-up and completely eliminates arcing. The multilayer thermal blanket operates by providing a strong electric field across the outer Kapton layer so that the incoming electrons are accelerated towards an inner conducting layer. The resulting enhanced leakage current ensures that the surface potential is kept to well below the threshold potential for spontaneous discharges. The principle of operation and the tests carried out to prove the effectiveness of this new blanket are presented.