Variable Emittance Coatings

Abstract

Variable emittance coatings (VECs) can reduce thermal control system mass and power by passively changing radiator heat rejection according to spacecraft and environment heat loads. VECs make establishing a lunar presence easier since this technology helps overcome challenges with harsh thermal environments on the lunar surface and in transit. This CIF focuses on creating testing capabilities to assess VECs from collaborators in academia and industry. Two main testing capabilities were created. First, a set of temperature dependent Fourier Transform Infrared Spectroscopy (FTIR) measurement accessories were designed, fabricated, and used to measure samples received from collaborators. These accessories are capable of measuring the transmittance and reflectance of semi transparent and opaque samples. Second, a vacuum calorimetry experiment was designed and built to assess the variable heat rejection of larger coupons.