Science: Sunny Outlook for Sunsats

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At a press briefing heralding the Energy Department study, Glaser replied to all these objections. He pointed out that solar satellites, unlike power plants that would use nuclear fusion, need no major technological breakthroughs; the space program has already shown that the required scientific know-how exists. What of the staggering costs? Glaser argued that after the turn of the century, when such satellites could be in operation, their electricity probably would be no costlier, and perhaps a lot cheaper, than power from oil, coal and nuclear plants. As for the danger from microwaves, Glaser conceded that this needs further study. But he pointed out that a satellite's beam would always be locked on target; in fact, it would disperse altogether if the satellite did not receive continuous electronic cues from a transmitter in the rectenna. Along its edge, said Glaser, the beam would be much less powerful than permissible leak age from a closed microwave oven.

For all the optimism radiated by Glaser and the Sunsat Energy Council, a coalition of individuals and corporations lobbying for his scheme, no one could deny SPS's enormous complexities.

Weighing up to 50,000 tons apiece, solar satellites would have to be built in space itself, with materials carried aloft by a new generation of craft considerably larger and more powerful than the NASA space shuttle. Looking like great Erector Sets, the structures, about six miles long and three miles wide, would be made of long thin beams actually manufactured in space out of rolls of aluminum or carbon-fiber strips about as thick as the wall of a beer can. In the weightlessness of orbit, nothing stronger would be needed.

Though much of the assembly would be automated, as many as 600 construction workers would have to be housed at the orbital site for months at a time. As NASA's problems with the space shuttle's heat-shielding tiles have shown, countless un expected difficulties could crop up in such a complicated undertaking.

Nonetheless, the House of Representatives was sufficiently fascinated by the proposal to pass a bill last year calling for $25 million in fiscal 1980 for further study of the concept, especially its environmental effects. Though the proposal died in the Senate, SPS advocates are now mounting a campaign for enactment of a similar measure by the next Congress.

They have one compelling argument in heir favor. This year the lawmakers passed a bill calling for $20 billion in spending for fusion research over the next two decades. Why not hedge that bet with a few million dollars at least to investigate another idea that may be every bit as promising?

— By Frederic Golden