Project Prometheus

Project Prometheus (also known as Project Promethian) was established in 2003 by NASA to develop nuclear-powered systems for long-duration space missions. This was NASA's first serious foray into nuclear spacecraft propulsion since the cancellation of the SNTP project in 1995. The project was planned to design, develop, and fly multiple deep space missions to the outer planets.

The project was cancelled in 2005, due to other demands on NASA's budget. Its budget shrank from $252.6 million in 2005 to only $100 million in 2006, $90 million of which was for closeout costs on cancelled contracts.