NuclearSpace
- The goal is to promote the use of nuclear power in space and to further enhance the manned exploration of our solar system.
- http://www.nuclearspace.com/

NERVA
- 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.
- http://www.ans.neep.wisc.edu/~ans/point_source/AEI/sep95/rocket_programs.html

How Stuff Works: How Fusion Propulsion Will Work
- 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.
- http://www.howstuffworks.com/fusion-propulsion.htm

Innovative Nuclear Space Power and Propulsion Institute
- 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.
- http://www.inspi.ufl.edu/

Nuclear Thermal Propulsion
- Federation of American Scientists' review of the topic.
- http://www.fas.org/nuke/space/