Collecting solar power in space and beaming it back to Earth is a relatively near-term possibility that could solve strategic and tactical security problems for the U.S. and its deployed forces, the Pentagon's National Security Space Office (NSSO) says in a report issued Oct. 10.

As a clean source of energy that would be independent of foreign supplies in the strife-torn Middle East and elsewhere, space solar power (SSP) could ease America's longstanding strategic energy vulnerability, according to the "interim assessment" released at a press conference and on the Web site spacesolarpower.wordpress.com.

And the U.S. military could meet tactical energy needs for forward-deployed forces with a demonstration system, eliminating the need for a long logistical tail to deliver fuel for terrestrial generators while reducing risk for eventual large-scale commercial development of the technology, the report says.

"The business case still doesn't close, but it's closer than ever," said Marine Corps Lt. Col. Paul E. Damphousse of the NSSO, in presenting his office's report.

That could change if the Pentagon were to act as an anchor tenant for a demonstration SSP system, paying above-market rates for power generated with a collection plant in geostationary orbit beaming power to U.S. forces abroad or in the continental U.S., according to Charles Miller, CEO of Constellation Services International and director of the Space Frontier Foundation.

By buying down the risk with a demonstration at the tactical level, the U.S. government could spark a new industry able to meet not just U.S. energy needs, but those of its allies and the developing world as well. The technology essentially exists, and needs only to be matured. A risk buy-down by government could make that happen, according to the NSSO report.

"This is not a 50-year solution," said John Mankins, an expert in the field and president of the Space Power Association. "The kinds of things that are possible today say a truly transformational demonstration at a large scale is achievable within this decade."

As an example, Mankins listed the rapid progress in boosting the efficiency of solar cells. While 20-25 percent efficiency was once considered a long-term goal, efficiencies on the order of 40 percent already have been achieved. And the modularity and scalability of the systems needed to build an SSP platform make testing relatively straightforward.

Even from its perch in low-Earth orbit, for example, the International Space Station could be used as a test bed for SSP components and even demonstrate low-level power transmission from orbit to Earth. The exposed facility on Japan's Kibo laboratory, due for launch in the first half of next year, could be used to test pointing and transmitting hardware, Mankins said, as well as to conduct space-exposure experiments on materials that might be used in building the large structures needed to collect sunlight in meaningful amounts.

The Internet-based group of experts who prepared the report for the NSSO recommended that the U.S. government organize itself to tackle the problem of developing SSP; use its resources to "retire a major portion of the technical risk for business development; establish tax and other policies to encourage private development of SSP, and "become an early demonstrator/adopter/customer" of SSP to spur its development.

That, in turn, could spur development of space launch and other industries. Damphousse said a functioning reusable launch vehicle - preferably single-stage-to-orbit - probably would be required to develop a full-scale SSP infrastructure in geostationary orbit. That, in turn, could enable utilization of the moon and exploration of Mars under NASA's vision for space exploration.