VO 2 -based Thermochromic Variable Emittance Coating

Abstract

As NASA’s Artemis program requirements become increasingly challenging for thermal control, novel passive thermal control solutions are needed to enable lunar surface and lunar transit operations. A thermochromic coating which changes its heat rejection with temperature could eliminate the need for dual loop thermal control architecture in human spacecraft and could reduce or eliminate the need for survival heaters in robotic spacecraft. The variable heat rejection is accomplished by incorporating a vanadium dioxide (VO 2 ) layer into a multilayer coating stack up. Intrinsically, VO 2 changes from an insulator to a metal at 68 °C, so a tungsten dopant is introduced to reduce the transition temperature to room temperature or below. This project is focused on developing a process for doping the VO 2 to achieve the desired transition temperature