HeetShield’s objective for this Phase I program is to demonstrate that a Flexible Gas Barrier (FGB) between the outer fabric layers of the Flexible Thermal Protection System (F-TPS) on the Hypersonic Inflatable Atmospheric Decelerator (HIAD) has the potential to reduce hot gas ingress to the interior fibrous insulation. Reducing hot gas ingress will reduce oxidation/recession of interior fibrous materials and reduce interior convective heating throughout the F-TPS. It is anticipated that the FGB materials will liquefy upon heating, that capillary action will draw it into the crevices in the outer fabric weaves to seal those crevices against mass flow, and that surface tension will hold the FGB in place while it remains in a liquid state. Although weight and bulk of the F-TPS is increased by adding the FGB, adding it is also expected to make the F-TPS significantly more effective such that other components can be made thinner and lighter, delivering a net weight and bulk reduction. In Phase I the feasibility of the FGB will be investigated through a series of tests that expose FGB prototypes to hot flames from a Meker burner and measure gas flow and its effects. F-TPS compatibility will be demonstrated by manufacturing an F-TPS specimen including the FGB, compressing that specimen to the representative volume, and evaluating the specimen for damage. Technical progress, and fabrication/manufacturing issues will be considered to assess hurdles in Phases II and III.
Improved HIAD technology will increase mission capabilities for Mars and beyond. HIAD is considered a key technology for human rated Mars Entry Descent and Landing (EDL). The materials developed in this Phase 1 effort will lead to improved Gen-3 HIAD FTPS that can handle higher heat loads and/or pack to a smaller volume. Applications include Mars, Venus, Titan, as well as payload return to Earth from LEO. HEOMD, STMD, and SMD can benefit from this technology for various exploration missions.
Methods to reuse spacecraft hardware are currently being developed by many companies including ULA, SpaceX, Blue Origin and Rocket Lab. In EDL areas where the hardware is flying at hypersonic velocities, a HIAD could be a key decelerator technology. This Phase I effort will provide more HIAD design options and expand the mission capability for these companies.