Nuclear electric ion propulsion for three deep space missions

Nuclear electric ion propulsion is considered for three sample deep space missions starting from a 500 km low Earth orbit encompassing the transfer of a 100 MT payload into a 1500 km orbit around Mars, the rendezvous of a 10 MT payload with the Jovian moon Europa and the rendezvous of a similar payload with Saturn's moon Titan. Near term ion engine and space nuclear reactor technology are assumed. It is shown that nuclear electric ion propulsion offers more than twice the payload for the Mars mission relative to the case when a nuclear thermal rocket is used for the trans-Mars injection maneuver at Earth, and about the same payload advantage relative to the case when solar electric propulsion is used for the Mars heliocentric transfer. For missions to the outer planets nuclear electric ion propulsion increases the payload mass fraction by a factor of two or more compared with high thrust systems that utilize gravity assist trajectories.