Project Helios

Helios was similar to Orion in that nuclear explosives were to be used for propulsion. However, with Helios the explosions were to be internal, within a spherical chamber. Water would be sprayed into the chamber just before detonation; the explosion would turn it to high temperature steam and it would be expelled through the rather large nozzle to produce thrust.

Helios didn't get even as far as Orion; it suffered from extreme complexity, low specific impulse and uncertainty as to whether it would actually hold together. Several designs were conceived, a few of which are shown here. The color artwork was from Lawrence Livermore National Lab, the B&W ad was from Aviation Week. No further data on these designs appears to be available.

You can find Scott's current page on Orion and Helios here. You can find ordering information on the Part-Time models home page.