The articles in the April 2002 special Energy Challenge issue of Physics Today seemed generally thoughtful and well-written. However, I was puzzled that nowhere in that issue, not even in Samuel Baldwin’s renewable energy article ( Physics Today 0031-9228 554200262 https://doi.org/10.1063/1.1480784page 62 ) covering solar power, was there a mention of solar power satellites, lunar solar power, or the other space-based alternatives that, in the long run, can provide us with an astronomically large, completely renewable energy resource—for example tens of terawatts from (admittedly large) satellites in geosynchronous orbit. Considering that these options have, in the past, been advocated primarily by physicists, including Gerard O’Neill, Freeman Dyson, and others associated with the Space Studies Institute, 1 it seems derelict of Physics Today to ignore the current status and future prospects of this energy option.

Fortunately, David Criswell provides an introduction to the lunar solar power option in a recent issue of The Industrial Physicist . 2 Space-based power has apparently suffered from NASA neglect at least since the 1970s, although an installed base of at least several hundred kilowatts is already in operation, powering satellites and the space station. Of course, there is always a battle for research funding, but the long-term potential usefulness of space-based solar power seems so immense that a more focused effort to develop this technology is long overdue.

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For more information on the Space Studies Institute, see http://www.ssi.org.
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The Industrial Physicist
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