Advanced Multifunctional MMOD Shielding

This project is developing micrometeoroid and orbital debris (MMOD) shields which incorporate thermal protection, radiation protection, damage detection & location sensors and self-healing properties. We are developing and demonstrating in hypervelocity impact tests: (1) MMOD toughened, smart thermal blankets, (2) combined MMOD/radiation protection shields, (3) shields incorporating self-sealing materials. Current state of the art MMOD shielding is single functional. Multifunctional MMOD shielding technology will reduce future spacecraft mass, and improve crew safety and mission success.

MMOD toughened, smart thermal blankets. The project was successful over the past two years in developing and demonstrating by test (hypervelocity impact and thermal vacuum tests) an MMOD toughened, smart thermal blanket concept that is adaptable to different levels of MMOD threat and/or reliability levels. This blanket includes integrated impact sensor technology to determine the location and extent of MMOD impact damage. Combined MMOD/radiation protection shields. The project also has made considerable progress in developing improved MMOD and radiation shields that have so far shown better MMOD performance than the best ISS MMOD shields, while decreasing radiation dosage by 30% from solar proton events (SPE). Self-sealing materials in MMOD protection. In FY13, impact tests on alternative shielding concepts will be performed that incorporate self-sealing materials able to close or reduce the size of holes in pressure shells. Tests to-date indicate that combinations of ionomer polymers and reinforcing materials are successful at closing 0.25" diameter holes in aluminum pressure shells under 0.3 atmosphere delta-pressure. Additional impact tests using these and other materials (thermoplastic and elastomeric polymers) are planned in FY13 for up to 1 atmosphere delta-pressure.