Endeavour: Williams has 'amazing ride' on spacewalk

CAPE CANAVERAL, Fla. (CP) - As he soared high above the Pacific Ocean, Canadian astronaut Dave Williams took a moment to marvel at the view while on a spacewalk to replace a broken part on the International Space Station.

"This is the most amazing ride I've ever had," Williams said Monday. Williams, along with American astronaut Rick Mastracchio, successfully replaced a broken gyroscope on the space station.

It was Williams' second spacewalk, and he's expected to do a third on Friday.

The record-breaking third spacewalk would make the Saskatoon-born and Montreal-raised astronaut the Canadian with the most time spent floating freely in space.

Williams' name has been mentioned if NASA decides there is a need to repair a gouge on the shuttle Endeavour, which carried Williams and six other astronauts to the space station.

NASA conducted a swift series of tests on the ground to determine whether the disturbingly deep gouge in Endeavour's belly needs to be fixed for re-entry.

 

The gouge is relatively small - nine centimetres by five centimetres - but part of it penetrates through the protective thermal tiles, leaving just a thin layer of felt material over the space shuttle's aluminum frame to keep out the re-entry heat of more than 1,100 degrees Celsius.

Mission managers expect to decide by Wednesday whether astronauts should go out and patch the gouge.

John Shannon, chairman of the mission management team, said the damage is benign enough for Endeavour to fly safely home; it's more a matter of avoiding extensive post-flight repairs to any possible structural damage.

"This is not a catastrophic loss of orbiter case at all. This is a case where you want to do the prudent thing for the vehicle," Shannon told reporters Monday evening.

NASA has never attempted this type of emergency repair on an orbiting shuttle, and two of the three remedies - all developed following Columbia's catastrophic re-entry - are untested in space. As in Columbia's case four years ago, Endeavour's gouge resulted from a piece of foam striking the shuttle at liftoff.

Despite extensive redesigning of the shuttle fuel tank that has already cost NASA a few hundred million dollars, foam has repeatedly fallen off the tank during launch, although nothing nearly as big as the piece that crippled Columbia.

American teacher-turned-astronaut Barbara Morgan and other crew members used a Canadian-made laser scanning system attached to the Endeavour's robot arm to create 3-D images of the gash and a few other damaged areas that NASA officials say pose no threat.

To patch the gouge, spacewalking astronauts would have to perch on the end of the shuttle's robotic arm and extension boom, be manoeuvred under the spacecraft, and either apply black paint, screw on a protective plate or squirt in goo.

The black coating, intended to help dissipate heat, was tested on a previous shuttle flight. The two other repair methods have been tested in vacuum chambers on Earth, but never in space.

The shuttle Columbia was destroyed in 2003 when hot atmospheric gases seeped into a hole in its wing and melted the wing from the inside out. A foam strike at liftoff caused the gash.

Canadian astronaut Roberta Bondar said danger is always there on shuttle mission.

"It's basically, you strap yourself to a bomb and everybody on board is a test pilot, regardless of whether or not you can control it for the last two minutes of re-entry," Bondar told reporters in Oakville, Ont.

"The space shuttle has always been an experimental vehicle, it was only Ronald Reagan who decided it wasn't, and as far as I know he had never been on one."

Monday's spacewalk, on the other hand, was much more routine.

Williams and Mastracchio floated out of the space station's airlock just after 11:30 EDT Monday. They carefully unbolted the broken gyroscope from a space station truss and replaced it with a new one Endeavour carried up. The spacewalk was completed at 6 p.m.

It was their second spacewalk in three days. During their first spacewalk on Saturday, Williams and Mastracchio installed a new beam to the International Space Station.

Astronauts plan to conduct two more spacewalks, on Wednesday and Friday. Williams is not slated to take part in Wednesday's spacewalk.

Endeavour has been docked with the space station since Friday.

It will remain there until Aug. 20 for a record 10-day stay, three days more than originally scheduled.

Endeavour's landing is now planned for Aug. 22.