Shuttle Commander Eileen Collins

[onedomino]

It's been a long road back.

Shuttle Commander Confident in Mission's Safety
By Dave Santucci
CNN

http://www.cnn.com/2005/TECH/space/02/24/space.shuttle/index.html

HOUSTON, Texas (CNN) -- Discovery commander Eileen Collins says the next shuttle mission will set a new standard for safety.

"This will be the safest mission NASA has ever flown," she told CNN Thursday, citing the research and development that has taken place in the more than two years since Columbia broke apart over Texas while on landing approach to Florida's Kennedy Space Center on February 1, 2003.

"We have a lot of training to do ... but we will be ready to go May 15," Collins said

The crew of seven will be the first to fly since the Columbia broke apart over Texas. The accident was caused by a piece of foam falling from the shuttle's external tank, striking the wing of the orbiter and leaving a hole that allowed hot gases to enter the vehicle and disintegrate it upon re-entry.

NASA astronauts Soichi Noguchi and Steve Robinson spent more than six hours Thursday simulating one of three spacewalks they are to make during their 12-day mission.

Only part of one of the spacewalks and some time inside Discovery will be spent testing the repair techniques NASA hopes will fix any holes that might develop in the shuttle's thermal protection system, which protects the shuttle during re-entry.

Among the most promising repair techniques are three for tiles and one for the reinforced carbon carbon (RCC) that protects the most critical parts of the shuttle from extreme heat during re-entry.

A gray reflective liquid will be tested in two areas, as a replacement coating if any tiles lose their heat-reflecting black coating, and as a primer for the shuttle tile ablator, which is basically goo that fills gaps between tiles.

A third tile-repair technique -- fastening what looks like sheets of metal over missing tiles -- will not be tested because it would release potentially hazardous particles from tiles into the air inside the shuttle.

NASA is still working on a way to patch a hole the size of the one that caused Columbia's demise.

To prevent a repeat of that problem, NASA has focused on stopping the external tank from shedding any foam large enough to cause damage. A newly designed tank has been shipped from its manufacturer, a Lockheed-Martin facility in Louisiana, and is now waiting to be mated to the space shuttle at the Kennedy Space Center in Florida.

NASA engineers say they are close to being able to fix holes as big as 6 inches in diameter in the RCC, using an overlay with a self-securing bolt on the back.

Discovery also will carry a new extension for its arm to allow astronauts for the first time to look over critical parts of the vehicle without embarking on a dangerous spacewalk. "The Boom," as it is known, has cameras and lasers on the end, designed to give the crew inside and engineers on the ground a view of cracks as small as one-20,000th of an inch.

Engineers told CNN they have confidence in the new techniques, but they've only been tested in labs on Earth. Should space shuttle managers determine the shuttle has a problem that cannot be repaired, the seven astronauts would join the two astronauts aboard the international space station and wait for a rescue shuttle.

Atlantis has been readied along with Discovery and will act as a rescue vehicle if needed.

Atlantis is scheduled to launch July 12.