A physicist has launched a new space start-up to develop a theoretical, 1-kilometer-long cannon space powered by hydrogen that could be housed below the surface of the ocean and could significantly reduce space launch costs.

NASA researchers are testing whether maglev technology, using high-strength magnets to lift and propel objects, could provide a cost-efficient alternative to current propulsion methods.

A new magnetic levitation -- or maglev -- track at the Marshall Space Flight Center in Huntsville, Ala., accelerates a model spacecraft from zero to 60 mph in less than one-half second.