NASA Plans Robotic Fix For Hubble

By Guy Gugliotta
Washington Post Staff Writer
Wednesday, August 11, 2004; Page A01

NASA has decided to move ahead with an ambitious mission to service the
Hubble Space Telescope using a robotic repairman to change batteries and
gyroscopes, add new instruments, and maybe fix a malfunctioning
spectrograph, agency officials said yesterday.

Al Diaz, associate administrator of NASA's Science Mission Directorate,
said NASA Administrator Sean O'Keefe traveled to Hubble's operational
headquarters at the Goddard Space Flight Center in Greenbelt late Monday
and instructed the engineers there to begin serious work to put the
robotic mission into space in 2007.

The decision marked a sharp turnabout for O'Keefe and NASA, which has
suffered withering criticism since a January announcement that it would
no longer service Hubble at all and would develop a robot whose only
purpose would be to steer the telescope out of orbit and safely into a
watery grave.

Diaz described the next nine months as "a design and testing phase" in
which engineers will work out details of the mission to prove that a
robotic servicing mission can be done. Then will come a "critical design
review," in which the agency will decide whether to commit the money to
finish the job. A successful mission would extend the life of the
15-year-old telescope by at least five years, Diaz said.

Since spring, Goddard engineers have expressed growing excitement about
the prospect of a robotic mission, in part because of the spectacular
test performance of the Canadian Space Agency's Special Purpose
Dexterous Manipulator, or "Dextre." The unit has two 10-foot arms that
pivot around a central "torso" and would do the job of replacing aging
Hubble components.

Dextre was designed to fly to the international space station in 2005
and is fully hardened for space. Diaz said NASA intends to do a
"sole-source" procurement focused on Dextre, but he acknowledged that
there are other contenders, including the University of Maryland's
"Ranger" and NASA's own "Robonaut."

"I think it's great," said Steven V.W. Beckwith, director of Baltimore's
Space Telescope Science Institute, which manages Hubble's scientific
work. "The amount of money that's being discussed is serious, and the
real challenge will be to see if the Hubble team can overcome the
technological challenges."

The robot, attached to an unmanned spacecraft that would dock with the
telescope, will be expected to change the batteries that provide
Hubble's electric power and the gyros that keep it aligned in space. It
will also add two new instruments and may even try to repair the
recently damaged Space Telescope Imaging Spectrograph, used to examine
black holes and discern the chemical composition of planets and stars.

NASA officials said O'Keefe told Goddard's Hubble team that the mission
would cost between $1 billion and $1.6 billion, which could make it
considerably more expensive than the $800 million to $1 billion spent on
space shuttle trips to the telescope, the method used to service Hubble
in the past.

But Diaz, speaking to reporters in a telephone news conference, said
planners have seen "a wide range of estimates" and are far from sure
what the eventual price might be. "We expect to have a dialogue with
Congress about the budget," he said.

The agency is likely to find a sympathetic ear. Congress has shown
bipartisan and consistent opposition toward plans to shut down Hubble,
and at one point it warned O'Keefe not to withdraw funds from the
telescope program pending a final decision on its fate.

Hubble, in orbit 360 miles above Earth, is one of the most successful
NASA projects ever undertaken. With periodic space shuttle visits for
overhauls and instrument updates, the telescope has produced generations
of spectacular images from the far reaches of the cosmos.

Concern over Hubble's future surged in January, when O'Keefe announced
that he was canceling the fourth shuttle servicing mission to the
telescope, citing safety concerns after last year's Columbia disaster.

Without servicing, NASA planners have said that Hubble's batteries will
wear out by the end of 2007 and that the telescope will shut down within
hours. From the beginning, NASA has declared 2007 as the deadline for
any repair mission.

Though O'Keefe early this year invited ideas for a robotic servicing
mission, the agency's attention initially focused on the need to develop
an autonomous vehicle that could dock with Hubble and steer it into the
sea, so that remnants of the telescope would not fall into populated areas.

Diaz said yesterday that "automated rendezvous and docking" is
"something we want to have anyway" for future exploration missions.
Russia currently has the only spacecraft with such a capability, but
European countries and Japan have similar vehicles under development.

O'Keefe remained adamant about the prohibitive costs in money and time
of developing the safety equipment for a shuttle mission, but the
National Academy of Sciences in June issued a report urging the agency
not to abandon that option altogether. "We are not doing anything to
preclude that alternative," Diaz said.

Diaz said engineers so far have found no task that is beyond the ability
of a robot, but he cautioned that they have not had time yet to assess
the risks of failure. "You must take into account the first principle,"
he said. " 'Do no harm.' "

Beckwith said the job would be very difficult for a robot but would
probably be doable. "Being able to open and shut the large bay doors is
the benchmark, because astronauts have had trouble doing that," Beckwith
said. "If you can't shut the doors, it would seriously cripple the
observatory."

Fixing the imaging spectrograph would also be difficult, he said,
because the malfunctioning part was not designed to be replaced. "For a
robot to do all of these things would be a stretch," he said. "But the
people looking at this are very, very good."

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