Low-alpha, variable emissivity radiator (LAVER) panels for passive thermal regulation of spacecraft

Physical Sciences Inc. (PSI) will produce a variable emissivity, low absorptivity radiator (LAVER) tiles to be applied to radiator panels for passive thermal regulation of spacecraft. The tiles will allow satellites, particularly SmallSats, and lunar craft, such as VIPER, to passively regulate variable thermal loads, reducing the size, weight, and complexity of their thermal control system. In a recently concluded Phase II SBIR program, PSI designed, developed, and demonstrated functionality of 2 LAVER tiles, demonstrating 3.25:1 emissivity contrast, and set point temperatures as low as 25C. The CCRPP program will build upon the successes of that Phase II program by adapting our manufacturing process to batch processing (~ m2 per batch), improving the technical performance, repeatability and reliability of the fabrication process, while lowering the cost per tile. At the conclusion of the program, we anticipate reaching TRL 7 and MRL 5. The purpose of the LAVER tiles is to passively regulate the temperature of spacecraft under variable heating and dissipating thermal loads without the use of power, heat loops, or other moving parts, simplifying the architecture of spacecraft thermal control systems as well as reducing their cost. PSI’s LAVER tiles can be tailored to specific applications (e.g. low earth orbit vs lunar) and thermal environments by small changes in the manufacturing process. This tunability makes our technology broadly applicable to all space craft integrators. In our technical program PSI will work toward the following technical objectives: 1) Increase the production size from 2” to > 4”, 2) improve VO2 production process controls, and 3) mature a novel coating design to produce low solar absorptivity on the LAVER tiles. In working toward these goals, LAVER tiles will obtain improved emissivity contrast, become compatible with high volume manufacturing, and be compatible with set-point temperature requirements from 70 C to at or below room temperature. In addition, PSI will work toward manufacturing improvements that will enable production volume to increase from ~4/day to > 50/day via increased automation, dedicated equipment for LAVER TILE manufacturing, while reducing the cost of tiles to be close to that of existing passive technology. NASA will receive test coupons demonstrating LAVER functionality near the midpoint and at the conclusion of the program.
Benefits: The LAVER tiles will provide near-term support to Class C and D missions, particularly SmallSats, where reduced size, weight, and power budget of systems is paramount. LAVER tiles will also support precursor missions such as VIPER, as well as parts of the Artemis mission such as the Lunar Lander and Gateway. The LAVER directly addresses a need within NASA Taxonomy Area 14; e.g 14.2.3 (Heat Rejection and Storage), and satisfies the technology push for ultralightweight radiators, as called out on the 2020 Technology Area Strategic roadmap. The LAVER tiles have applications on the thermal regulation of commercial satellites and commercial space flight vehicles.