Development of a Small Nuclear Thermal Propulsion Flight Demonstrator Concept that Is Scalable to Human Missions

摘要

Recent exploration architectures are considering capability based approaches that use various propulsion technologies that need flight qualification. When human exploration missions come to fruition, rapidity of mission flight time and minimization of the number of flight elements will be important to reduce risk and cost. Nuclear thermal propulsion (NTP) is a technology that enables rapidity of transit and minimizes the number of spacecraft systems and launch vehicles to enable robust exploration. NTP has been proven scientifically and many engineering challenges have been addressed in past ground testing. The final validation and verification that still remains is to prove NTP in a flight demonstrator. Current efforts are focused on reducing demonstrator cost via application of proven liquid rocket components and fuel element design technology evolution. Pratt & Whitney Rocketdyne has been working with NASA Glenn Research Center to conceptualize the reactor design requirements and propulsion system design relative to a small NTP with scalability to human exploration spacecraft systems. Studies performed in 2011 and continuing through 2012 have defined the reactor neutronics, thermodynamic cycle, and component mass for a small NTP and the scalability of the design for larger (e.g., 25,000lbf) propulsion systems. Part of these studies has shown this small NTP can be flight demonstrated using current Delta IV and Atlas V expendable launch vehicles and provide improved capability for robotic exploration missions. Nomenclature