NASA said this week that it would team up with DARPA, the Pentagon’s R&D arm, to build, launch, and demonstrate a nuclear thermal engine. This early work is intended to pave the way for a crewed mission to Mars in the late 2030s. The joint project has a $110M budget this year and will likely cost hundreds of millions more through deployment, planned for 2027.
NASA and DARPA are focused on speeding up the voyage to Mars and other deep space destinations. “If we have swifter trips for humans, they are safer trips," NASA Deputy Administrator Pam Melroy said Tuesday.
A successful fusion engine would really open up the solar system to human exploration. Still sci-fi for now but worth researching.