http://www.opednews.com/articles/Plans-for-Nuclear-Rockets-by-Karl-Grossman-Nuclear-Fission_Space-Colonization_Space-Defense-Weapons_Space-Exploration-Travel-141124-867.html

Plans for Nuclear Rockets in the Wake of Recent Space Accidents
By Karl Grossman
11/24/2014

The recent crash of Virgin Galactic's SpaceShipTwo and explosion on launch three days earlier of an Antares rocket further underline the dangers of inserting nuclear material in the always perilous space-flight equation--as the U.S. and Russia still plan.

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And in recent times, solar power has been increasingly shown to be practical even to generate on board electricity for missions far out in space. On its way to Jupiter now is NASA's Juno space probe, chemically-propelled and with solar photovoltaic panels generating all its on board electricity. When Juno reaches Jupiter in 2016 it will be nearly 500 million miles from the Sun, but the high-efficiency solar cells will still be generating power.

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Among other ways of propelling spacecraft, discussed at a Starship Congress last year in Texas was a system using orbiting lasers to direct beams on to a spacecraft. The magazine New Scientist said "beam sails are regarded as the most promising tech for a starship."

A scientist long-involved in laser space power research is Geoff Landis of the Photovoltaics and Space Environment Branch at NASA's Glenn Research Center in Cleveland who, in a 2002 NASA publication, "The Edge of Sunshine," wrote: "In the long term, solar arrays will not have to rely on the Sun. We're investigating the concept of using lasers to beam photons to solar arrays. If you make a powerful enough laser and can aim the beam, there's really isn't any edge to sunshine--with a big enough lens, we could beam light to a space-probe halfway to alpha-Centauri!"