'Bimodal' Nuclear Thermal Rocket (BNTR) Propulsion for an Artificial Gravity HOPE Mission to Callisto

摘要

This paper summarizes the results of a year long, multi-center NASA study which examined the viability ofrnnuclear fission propulsion systems for Human Outer Planet Exploration (HOPE). The HOPE mission assumes a crewrnof six is sent to Callisto, Jupiter's outermost large moon, to establish a surface base and propellant production facility.rnThe Asgard asteroid formation, a region potentially rich in water-ice, is selected as the landing site. High thrust BNTRrnpropulsion is used to transport the crew from the Earth-Moon LI staging node to Callisto then back to Earth in less thanrn5 years. Cargo and LH2 "return" propellant for the piloted Callisto transfer vehicle (PCTV) is pre-deployed at the moonrn(before the crew's departure) using low thrust, high power, nuclear electric propulsion (NEP) cargo and tanker vehiclesrnpowered by hydrogen magnetoplasmadynamic (MPD) thrusters. The PCTV is powered by three 25 klbf BNTR enginesrnwhich also produce 50 kWe of power for crew life support and spacecraft operational needs. To counter the debilitatingrneffects of long duration space flight (-855 days out and -836 days back) under "0-gE" conditions, the PCTV generatesrnan artificial gravity environment of "l-gE" via rotation of the vehicle about its center-of-mass at a rate of-4 rpm. Afterrn-123 days at Callisto, the "refueled" PCTV leaves orbit for the trip home. Direct capsule re-entry of the crew atrnmission end is assumed. Dynamic Brayton power conversion and high temperature uranium dioxide (UO2) in tungstenrnmetal "cermet" fuel is used in both the BNTR and NEP vehicles to maximize hardware commonality. Technologyrnperformance levels and vehicle characteristics are presented, and requirements for PCTV reusability are also discussed.