NASA OKs July 1 shuttle liftoff despite objections

By Irene Klotz

CAPE CANAVERAL, Florida (Reuters) – NASA managers cleared
the shuttle Discovery for launch on July 1, over the objections
of the agency’s top safety officer and its lead engineer,
officials said on Saturday.

“There were very different viewpoints on the issue of
whether we were ready to fly or not,” NASA Administrator
Michael Griffin told a news conference. “I can’t possibly
accept every recommendation given to me by every member of my
staff, especially when they all don’t agree.”

The crux of the debate was whether additional modifications
to the shuttle’s fuel tank were necessary before flights
resume. NASA redesigned the tank after the 2003 Columbia
accident and then again following the first post-Columbia
mission last July. Both times, large pieces of insulating foam
fell off the tank.

Columbia was hit and damaged by the falling debris,
triggering the ship’s breakup as it flew through the atmosphere
for landing. Seven astronauts aboard died in the accident.

Discovery escaped impact from falling foam debris during
its launch last July, but NASA suspended flights for additional
modifications. Some engineers say the agency has not gone far
enough.

Griffin and other top managers acknowledge the risk of
potentially dangerous debris impacts on the shuttle and have
appointed a special team to redesign the most troublesome
areas, known as ice frost ramps. These hand-sprayed chunks of
foam cover metal brackets on the outside of the tank. The foam
keeps ice from forming, which could break off and strike the
shuttle during liftoff.

Although smaller than the debris chunks that downed
Columbia and flew off during Discovery’s July 2005 launch, in a
worst-case scenario ice frost ramp foam could strike a shuttle
and damage its heat shield.

Even if that were to occur, said Griffin, the shuttle crew
would not be threatened. Since the Columbia accident, NASA has
set up a safe haven for shuttle astronauts aboard the
International Space Station should their vehicle become too
damaged to safely return to Earth. In addition, shuttle crews
now scrupulously inspect their ship for heat shield damage with
a new sensor-laden boom after reaching orbit.

“We’re not in the situation that we were in with during
Columbia,” Griffin said.

What was at risk, he added, was the ability to finish
building the space station if NASA did not get on with flights.
The shuttle fleet is to be retired in 2010. Sixteen more
missions to finish station assembly are planned, plus a
possible final servicing call to the Hubble Space Telescope.

Delaying Discovery’s launch until a new ice frost ramp
design is ready would put more pressure on the shuttle program
during the final years of station assembly, Griffin said.

While the loss of another vehicle likely would end the
shuttle program, Griffin said he was willing to accept that
risk in order to complete the station before the fleet is
retired.

“If we’re going to fly, we need to accept some programmatic
risks — not crew risks — and get on with it,” Griffin said.