WASHINGTON
- Advocates of using satellites to beam solar power from space to Earth hope
U.S. President Barack Obama's campaign promise to develop alternative energy sources
will help resurrect NASA's interest in the technology.
NASA has
been without an official space
solar power program since 2002, although a coalition of government
and private industry volunteers has kept alive visions of demonstrating how the
United States might one day draw energy from the sun and transmit it to Earth
via microwave beams.
The
volunteers were disappointed in December upon learning that NASA would not
provide $55 million they had asked for to conduct a solar power beaming
experiment they had devised for the International Space Station. The
experiment's designers are hoping it will get another look by the Obama
administration.
The
experiment entails placing a system that includes traveling wave tube
amplifiers, which amplify radio frequency signals, outside the space station on
the Japanese Experiment Module's Exposed Facility. The amplifiers, donated
by the U.S. Air Force Research Laboratory, would be moved to another location
on the space station to draw power from the station's solar arrays and beam
them to Earth in microwave form.
Old
concept, new energy
While Obama
has not identified space solar power as an alternative
energy source he would pursue, advocates are encouraged by his appointment
of longtime space solar power proponents Alan Ladwig and George Whitesides to
senior positions at NASA. These advocates note that Obama's transition team
specifically asked NASA about the space station power beaming experiment.
John
Mankins, who worked at NASA for 25 years and managed the space-based solar
power program, said NASA should play a part in U.S. attempts to achieve energy
independence.
"I don't
see how NASA or the space program can stand aloof from these [alternative
energy] efforts," Mankins said. "Whether or not there's opportunity for space
solar power, I think it's premature to say."
Mankins,
who recently
demonstrated for the Discovery Channel that a miniscule amount of
power can be received from a 20-watt microwave beam transmitted over a
distance of 92 miles (148 km), said the United States should conduct a thorough
study of end-to-end systems needed for space solar power, followed by
technology experiments and demonstrations. The last such systems study was
done 12 years ago, he said.
The concept
faces a major barrier, however, in the high cost of launching satellites large
enough to transmit meaningful amounts of power to Earth, according to a white
paper submitted by space solar advocate Charles Miller, president of Space
Policy Consulting Inc. in Dayton, Ohio, to Obama's transition team in
November. The white paper recommends establishing a national space solar power
policy, assigning a lead federal agency and an incremental research program.
The white paper said the cost of space solar power could be reduced if the
United States develops more-affordable access to space and applies high-volume
assembly line techniques to satellite construction.
Military
space power
Alternative
energy advocates are not the only ones interested in space solar power beaming;
the U.S. military is also eying
the technology as a possible means of delivering power to remote areas of
the globe. The Air Force Academy, for example, has begun building two
small satellites to test the concept of transmitting solar power from space via
laser technology. That demonstration is expected to produce enough power to
illuminate a single one-tenth-of-a-watt light emitting diode, or LED.
Meanwhile,
the space station power beaming experiment has won support from Gary Payton,
undersecretary of the Air Force for space.
Following a
briefing on the proposed demonstration, Payton wrote Bill Gerstenmaier,
NASA's space operations chief, to say the space agency and Pentagon should
begin exploring ways to collaborate on solar power beaming experiments.
"I believe
it is time for NASA and [the Defense Department] to collaborate on a project to
demonstrate safe space-to-earth transmission of solar energy is possible, and
scalable to a magnitude that can enhance national security interests," Payton
said in the Sept. 30 letter.
Power
stall
In
December, however, top NASA managers directed work on the project within the
U.S. space agency to stop.
Mack
Henderson of Johnson Space Center in Houston, who has been NASA's lead on the
space station demonstration, announced the decision in a Dec. 11 letter to
members of the group.
"It is with
heavy heart that I tell you that we have been asked to terminate all NASA's
support on the [space solar power] demo activity. This direction was just
received from management and I wanted to pass it along to you as soon as
possible to avoid wasting any more additional work that you have most
graciously been volunteering," Henderson wrote.
One member
of the group, who asked not to be identified, expressed frustration that the
program was canceled before the Obama administration took office.
"This is an
opportunity for NASA to be involved in not only something that involves space
but also energy and environmental issues," said one team member, who asked not
to be identified. "I think NASA management was fearful that they were going to
be handed this mission."
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