Spacewalking astronaut repairs heat shield 

Spacewalking astronaut repairs heat shield

Spacewalking astronaut repairs heat shield



Spacewalking astronaut Steve Robinson plucked a couple of loose fibre strips from Discovery's belly Wednesday in an unprecedented repair to the shuttle's heat shield.

"I'm grasping it and I'm pulling it and it's coming out very easily. Beautiful. Nice," Robinson radioed as he pulled the material out from between the heat resistant tiles on the shuttle's underside. "It looks like this big patient is cured."

With fellow spacewalker Soichi Noguchi watching from a perch on the International Space Station, to which Discovery is docked on the first shuttle flight since the 2003 Columbia disaster, Robinson was lowered on the station's robot arm to an area below Discovery's nose.

Moving deliberately, he used his gloved fingers to tug out the two strips with surprisingly little effort. Robinson carried a small hacksaw, scissors and forceps in case he could not pull the strips out.

The strips, made of ceramic covered cloth, are thought to have come loose from their adhesive bond and, although protruding only 2.5 centimetres, NASA engineers feared they could change the aerodynamics enough during landing on Monday to cause dangerous heat damage to the shuttle.

Robinson was the first astronaut in the 24-year shuttle programme to spacewalk to a shuttle's underside and, once there, the first to fix the heat shield during flight.

In a press conference from space on Tuesday, Discovery astronauts said they initially had misgivings about Robinson's spacewalk because they were not convinced it was necessary. But, they said, they supported it because it seemed an easy thing to do.

NASA admitted it did not know if the protruding strips were a danger to the shuttle, but after 2 1/2 years of work and US$1 billion spent on safety upgrades since the Columbia disaster, the agency was taking no chances it could lose another shuttle to heat damage.

Agency officials said on Tuesday they are even considering another spacewalk tomorrow to fix a protrusion in an insulating blanket outside the shuttle commander's window.

Source: China Daily