An experimental study was conducted in conjunction with the research and development program at the NASA Marshall Space Flight Center (MSFC) on thermal protection systems (TPS) for aerospace applications, a new concept for reusable TPS material. The new system uses a micro-encapsulated phase-change material rather than an ablative material to dissipate the heat produced during supersonic flight. This new material absorbs energy as it goes through a phase change during the heating portion of the flight profile and then the energy is released as the material cools. This new TPS consists of micro-encapsulated phasechange material and a resin system to adhere the coating to the structure. The technology has been successfully tested in the hot gas tunnel (aero-thermal heating). The figure shows the test results.

Surface versus surface-temperature comparison for different thicknesses of TMC with 50% loading. (9.4 BTU/ft²s heating rate for 100 s.)
The coating can also be applied to space structure system components to control their temperature. The radiant solar energy will be absorbed and stored by the coating, keeping the substrate at a design temperature and released back to the substrate during the eclipse (cold). The samples of TMC were placed on the MISSI rack for four years to study the long-term effect of atomic oxygen and UV radiation exposure on the thermal and physical properties of the material. The results showed very little mass loss.

The coating is unaffected by ultraviolet rays, produces no residue or side effects, can be pigmented to any color, is nonablative and environmentally friendly, and will not affect telemetry or communications performance.

This work was done by Raj Kaul of Marshall Space Flight Center. For more information, contact Ronald C. Darty, Licensing Executive in the MSFC Technology Transfer Office, at This email address is being protected from spambots. You need JavaScript enabled to view it.. Refer to MFS-31593-1.

NASA Tech Briefs Magazine

This article first appeared in the February, 2016 issue of NASA Tech Briefs Magazine.

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