NASA Rebuts New Criticism Over Hubble
By DENNIS OVERBYE

Published: February 10, 2004

[N]ASA officials yesterday defended their decision to end space
shuttle missions to service the Hubble Space Telescope, thus
dooming it to die within a few years. They said recent criticism
of the plan had oversimplified the issue.

In a telephone conversation with reporters, William F. Readdy,
the agency's associate administrator for spaceflight, said the
agency had prepared a point-by-point rebuttal of a pair of papers
distributed last week by an anonymous NASA engineer. The papers
challenged NASA's assertion that ending the service missions
could be justified on safety grounds.

The rebuttal, Mr. Readdy said, would be presented to the House
Science Committee, which is holding hearings on the space program
this week.

Sean O'Keefe, NASA's administrator, dismayed astronomers last
month by canceling further shuttle missions to the telescope,
meaning it will die in orbit in 2007 or so, prematurely ending
one of the agency's most successful and popular science missions.
Scientists say the telescope could keep working into the next
decade if servicing continued. All the remaining shuttle missions
are committed to finishing the International Space Station.

Mr. O'Keefe said he based his decision on safety, noting that
astronauts needed a "safe haven" to inspect and repair the
outside of the shuttle or to await rescue, if necessary. The
telescope offers no such protection.

The engineer's papers, distributed on Capitol Hill last week and
given to The New York Times by a scientist who disagrees with
NASA, challenge that reasoning. The documents, online at
nytimes.com/science, noted that the board investigating the
Columbia space shuttle disaster recommended that the agency
develop a way to repair the shuttle's fragile skin, regardless of
whether the shuttle is docked. NASA has embraced the board's
recommendations.

Moreover, the engineer argued, the requirement of a safe haven
during a mission to the telescope could be satisfied by having
another shuttle ready to make a rescue.

Mr. Readdy said NASA had already considered those ideas and
rejected them. In particular, he said, having a second shuttle
standing by would commit the agency to make dangerously fast
decisions.

"We would be buying into extreme schedule pressure if we went
with this," he said. What, he asked, if the rescuers sustained
the same damage as the first shuttle? "Then you would rescue no
one," he said.

Although Mr. O'Keefe has agreed to have his decision reviewed by
Adm. Harold W. Gehman Jr., chairman of the Columbia accident
board, NASA officials suggested that for astronomers should
accept the inevitable and make the telescope's last years as
productive as possible.

Copyright 2004, The New York Times Company