Early Track NEP system options for SEI missions

A development option for nuclear electric propulsion, the 'Early Track' option, is considered from system and mission application viewpoints. The intent of this development option is to address demanding missions of the future, such as robotic outer planet exploration or the Space Exploration Initiative. The 'Early Track' scheme utilizes existing technologies, such as the SP-100 space reactor and radiator components, as well as subsystems scalable from existing programs, such as 50 to 100 kWe ion thrusters. Up to 1.5 MWe of powder can be generated by the existing 2.4 MWt SP-100 reactor through the use of dynamic Rankine or Brayton power conversion. The performance characteristics of these systems are projected, and assessed for SEI missions currently under consideration.