Radiation and H2 Durable Nuclear Thermal Propulsion Fuel Element Insulator

NASA’s Marshall Space Flight Center (MSFC) has identified a need for new higher-temperature fuel element insulators for fission-based, liquid hydrogen (H2) fueled, Nuclear Thermal Propulsion (NTP) engines. NanoSonic is a small, advanced materials company currently supporting two NASA CubeSat flights in 2025 with our radiation shields as well as the LGM-30G Minuteman III Intercontinental Ballistic Missile (ICBM) with parts that must survive extremely harsh environments. While NTP reactors offer a specific impulse of ~ 900 seconds, more than twice that for state-of-the-art chemical rocket engines such as the Saturn V, weight reductions are still needed. Space nuclear propulsion (SNP) and doubled fuel efficiency may cut current transit time to Mars of 6-months by half, as well as astronauts’ exposure to galactic cosmic radiation (GCR) and supplies needed. Current insulators are based on combinations of SiC, ZrC, and graphite materials. For this SBIR, a new low thermal conductivity nanoporous ceramic insulator is offered based on SiC and ZrC MXenes layered with HfC and TaC to increase thermal stability up to ~4,000 ºC. This design shall minimize heat transfer between the high temperature fuel elements of 2727 ºC and lower temperature moderator material of 527 ºC to enable further mass reductions and higher-temperature gas-reactor performance for future small NTP reactors.