Federation of American Scientists' review of the topic.
Researching square lattice honeycomb ternary carbide fuels and nuclear electric propulsion based on gaseous and liquid fuel reactors with magnetohydrodynamic power generation systems, among other things.
Shows how building a fusion-powered spacecraft would be equivalent of developing a car on Earth that can travel twice as fast as any car with a fuel efficiency of 7,000 miles per gallon.
The Nuclear Engines for Rocket Vehicle Applications project. Started by the Atomic Energy Commission and NASA in 1961 and cancelled in 1971 due to radiation worries and a lack of interest from NASA.
The goal is to promote the use of nuclear power in space and to further enhance the manned exploration of our solar system.