Project Orion and Future Prospects for Nuclear Pulse Propulsion

The race to the Moon dominated human space e ight during the 1960s and culminated in Project Apollo, which placed 12 men on the lunar surface. Unbeknownst to the public at that time, several U.S. government agencies sponsored another project that could have conceivably placed large bases on the moon and eventually sent crewed expeditions to Mars and the outer planets within the same period of time as Apollo, and for approximately the same cost. The project, code-named Orion, featured an extraordinary propulsion method known as nuclear pulse propulsion. First conceived at the dawn of the space age, the concept was as radical then as it is now. However, its feasibility was never dismissed on purely technical grounds. In fact, many of the scientists and engineers who came into contact with the program over its seven-year lifetime became convinced of its viability. The political and nontechnical issues that e nally sealed the program’ s fate would certainly make the original Orion unacceptable by today’ s standards. However, new technologies and ideas developed since then could mitigate some of the major issues, and make nuclear pulse propulsion less unreasonable to consider for future human exploration, at least beyond Mars orbit. These new approaches are presented, following a discussion of the technological rationale for nuclear pulse propulsion and a general history of the concept.