Nuclear pulse propulsion

Nuclear pulse propulsion or external pulsed plasma propulsion is a hypothetical method of spacecraft propulsion that uses nuclear explosions for thrust. It originated as Project Orion with support from DARPA, after a suggestion by Stanisław Ulam in 1947. Newer designs using inertial confinement fusion have been the baseline for most later designs, including Project Daedalus and Project Longshot.

History

1940s

Calculations for a potential use of this technology were made at the laboratory from and toward the close of the 1940s to the mid-1950s.

1950s-1960s

Project Orion was the first serious attempt to design a nuclear pulse rocket. A design was formed at General Atomics during the late 1950s and early 1960s, with the idea of reacting small directional nuclear explosives utilizing a variant of the Teller–Ulam two-stage bomb design against a large steel pusher plate attached to the spacecraft with shock absorbers. Efficient directional explosives maximized the momentum transfer, leading to specific impulses in the range of 6,000 s (59 km/s) seconds, or about thirteen times that of the Space Shuttle main engine. With refinements a theoretical maximum specific impulse of 100,000 s (980 km/s) (1 MN·s/kg) might be possible. Thrusts were in the millions of tons, allowing spacecraft larger than 8×106 tons to be built with 1958 materials.

The reference design was to be constructed of steel using submarine-style construction with a crew of more than 200 and a vehicle takeoff weight of several thousand tons.