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A congressional committee has recommended a $20 million increase to the US space agency NASA's budget to study a controversial idea that was all but laid to rest in the 1980s — solar power satellites (SPS) for beaming energy to Earth.

The increase is being urged by members of the House of Representatives, including space subcommittee chairman Dana Rohrabacher (Republican, California), who either have a long-standing interest in solar power satellites or who represent NASA centres that would conduct some of the research.

The idea of collecting solar energy with large satellites in space and transmitting it to the ground via microwaves was first proposed in 1968. Some $50 million was spent on research at the Department of Energy and NASA in the late 1970s, but the concept was eventually shelved as being too expensive and requiring too many leaps in technology.

Last year, however, a small NASA team completed a two-year study of solar power satellites and found that enough had changed to warrant a revived research programme. Solar cell technology has improved, satellites are smaller and lighter, and SPS concepts no longer need hundreds of astronauts building gigantic structures in space.

NASA had planned to increase spending on SPS-related research from $2 million to $5 million next year. But the Marshall Space Flight Center in Alabama is now working on an implementation plan for SPS research should the House and Senate approve the $20 million increase later this year.

The House appropriations committee has called for NASA's Marshall and Lewis centres and its Jet Propulsion Laboratory to work with the energy department and private industry on SPS research. NASA is also funding Resources for the Future, a Washington think-tank, to conduct an economic analysis of the concept.

Proponents of SPS are more cautious in selling the idea than in the 1970s, when the satellites “only came in one size, and that was big,” according to Whitt Brantley of Marshall's Advanced Systems and Technology Office. Short-term research is likely to focus on modest experiments to advance the basic technology, such as point-to-point transmission of large amounts of microwave energy on the ground or in low orbit.

But SPS must overcome the stigma resulting from the unrealistic plans of 20 years ago. Christopher Flavin of the Worldwatch Institute, which has been studying the terrestrial solar power industry, calls SPS “a real throwback,” and criticizes Congress for starving conventional solar power research while pushing SPS.