NASA orders risky launch pad repair on shuttle

By Irene Klotz

CAPE CANAVERAL, Florida (Reuters) – The U.S. space agency
NASA on Friday decided to go ahead with a risky and
unprecedented launch pad repair on the space shuttle Atlantis
to replace bolts that might come loose during liftoff.

Atlantis is being prepared for an August 27 launch on the
first shuttle mission to resume construction of the
International Space Station since the 2003 Columbia disaster.

NASA has flown the shuttle Discovery twice since July 2005
to test safety upgrades made after the fatal accident, in which
Columbia fell apart on re-entry. But assembly of the
$100-billion orbital outpost has been on hold.

The bolts the agency plans to replace attach the shuttle’s
primary communications antenna to the ship’s payload bay wall.

“The managers decided there was enough uncertainty that
they wanted to go ahead and change the bolts,” said NASA
spokesman Grey Hautaluoma.

The work was not expected to delay liftoff, said launch
director Mike Leinbach.

Engineers recently discovered that two of the four bolts
were too short, a mistake made during the manufacturing of the
spacecraft 25 years ago.

Atlantis has made 26 flights with no problems. NASA,
however, is concerned that if vibrations during launch loosen
the bolts, the antenna could break off and crash down into the
shuttle’s 60-foot-long (18.3-metre-long) payload bay, with
potentially catastrophic results.

Incorrect bolts also were found and recently replaced on
sister ships Discovery and Endeavour. The problem, however, was
not caught before Atlantis was hauled to the launch pad on
August 2, said shuttle program manager Wayne Hale.

To reach the antenna, technicians plan to set up work
platforms near the top of a six-story-tall chamber that fits
around the shuttle’s payload bay.

Reaching the bolts will be a tight squeeze and workers will
have to be careful not to drop anything or bump the shuttle’s
robot arm or extension boom.

The cargo hold contains a $372-million power module, which
is to be the first major new addition to the space station in
nearly four years.

The station’s larger modules can only be carried into space
by the shuttles and NASA has until 2010, when the fleet is
retired, to finish the half-built outpost.