* Experiment to be installed during spacewalk Tuesday
* Shuttle Atlantis on 135th and final flight
* Orbital debris no threat to space station
By Irene Klotz
HOUSTON, July 11 With the end of the space
shuttle program, the U.S. government intends to stimulate
development of private space transportation and also to lay the
foundation for an entire new industry to service satellites in
The Robotic Refueling Mission flying aboard the space
shuttle Atlantis will use the International Space Station's
Dextre robot to test tools for refueling and repairing existing
satellites, none of which were designed with reuse in mind.
"I've likened it to a Fisher-Price play toy for a robot,
and I don't mean that in a negative sense," Atlantis commander
Chris Ferguson said in a preflight interview.
Ferguson and three crewmates arrived at the space station
on Sunday to deliver a year's worth of food, clothing and other
supplies. The mission is the 135th and final flight in the
30-year-old shuttle program, which is ending due to high
NASA hired two firms, Space Exploration Technologies and
Orbital Sciences Corp ORB.N, to deliver cargo to the station
beginning next year. The Obama administration wants NASA to buy
rides for its astronauts as well, though no commercial
suppliers are expected to be available until around 2015. In
the meantime, the United States will pay Russia for space taxi
flights, at a cost of more than $50 million a seat.
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The $22.6 million Robotic Refueling Mission equipment is
scheduled to be installed to the outside of the space station
during a 6.5-hour spacewalk on Tuesday.
The hardware consists of a box of tools, fittings and a
tank of ethanol fuel that the station's Dextre robot can use to
perform tasks that would be needed to refuel a satellite, such
as cutting away thermal insulation and wires, removing
protective caps, installing fuel valves and transferring fuel
from one tank to another.
The test work, which won't start until after the shuttle
leaves the station, is scheduled to run for two years. NASA
plans to hire an industry partner for a follow-on mission
around 2015 to refuel a U.S. government weather satellite and
then nine other spacecraft in orbit
"We want the commercial world to take over this service,"
said Benjamin Reed, deputy project manager for the Satellite
Servicing Capabilities Office at NASA's Goddard Space Flight
Center in Maryland.
There are currently about 360 operational commercial
communications satellites and another 100 government-owned
satellites orbiting Earth.
"Every single one of them one day is going to run out of
fuel and be thrown away. That's the way it's always been done.
If a robot can go up and refuel it, you wouldn't have to throw
it away," Reed said.
Because the satellites weren't designed with refueling in
mind -- they have no navigational aids, no reflectors, nothing
to help guide in an approaching spacecraft -- the technical
hurdles are steep.
Since the same technology also could be used to disable
satellites, Reed said NASA intends to be as open as possible
about the project.
"We plan an international workshop next spring where we
will lay out in more detail what our plans are to make the
world aware of what we are doing so that we can minimize the
anti-satellite weapon accusers," Reed said.
The spacewalk to install the project's trial run will be
conducted by NASA's two space station crewmembers, Ron Garan
and Mike Fossum.
The agency said on Monday that a piece of orbital debris
that had been projected to pass near the station about the time
of the spacewalk was not a threat. The debris, part of a
defunct Soviet satellite, should pass about 11 miles (18 km)
from the station, said NASA flight director Jerry Jason.
NASA figures that over a six-month period, the space
station has a 1-in-100 chance of being hit by a piece of debris
and sustaining damage that might have to force the crew to
evacuate part of the station, said spokesman Kelly Humphries.
Overall, the chance of a debris strike to the shuttle
during its 12-day flight is 1-in-314.
Atlantis, which blasted off on Friday from the Kennedy
Space Center, is due back on July 20.
(Editing by Jane Sutton and Cynthia Osterman)