Nuclear Thermal Rocket/Stage Technology Options for NASA's Future Human Exploration Missions to the Moon and Mars

The nuclear thermal rocket (NTR) provides a unique propulsion capability to planners and designers of future human exploration missions to the Moon and Mars. In addition to its high specific impulse (Isp ∼ 850–1000 seconds) and engine thrust‐to‐weight ratio (∼ 3–10), the NTR can also be configured as a “dual mode” system capable of generating stage electrical power. At present, NASA is examining a variety of mission applications for the NTR ranging from an expendable, “single burn” trans‐lunar injection (TLI) stage for NASA's “First Lunar Outpost” (FLO) mission to all propulsive, “multi‐burn,” spacecraft supporting a “split cargo/piloted sprint” Mars mission architecture. Two “proven” solid core NTR concepts are examined ‐one based on NERVA (Nuclear Engine for Rocket Vehicle Application)‐derivative reactor (NDR) technology, and a second concept which utilizes a ternary carbide “twisted ribbon” fuel form developed by the Commonwealth of Independent States (CIS). Integrated systems and mission study results...