May 31, 2006

Space Shuttle Clears Critical Hurdle for Launch

By Irene Klotz

CAPE CANAVERAL, Florida -- U.S. space shuttle Discovery on Wednesday passed a critical technical review to determine if modifications made to its fuel tank would significantly reduce the chances of a Columbia-like disaster.

The shuttle is on the launch pad being prepared for a July 1 liftoff to the International Space Station. Two more flight reviews are pending before Discovery is cleared for launch on its second flight since the February 2003 Columbia disaster.

During two days of meetings, about 100 engineers gathered at the Kennedy Space Center to discuss the chances that foam insulation would peel off the shuttle's external fuel tank and strike the ship, as happened during Columbia's launch and during the July 2005 flight of Discovery on the first post-accident mission.

"We have found no showstoppers," shuttle program manager Wayne Hale told a news conference after the meeting.

He said engineers had made "significant improvements" in the tank's design since falling insulation struck and pierced Columbia's protective heat shield, triggering its breakup and the deaths of seven astronauts.

A large chunk of foam also fell off the tank when Discovery launched two years later.

The biggest change in the tank's design since last year was the removal of two long foam windshields that protect cables and pressurization lines located on the outside of the tank.

Hale warned that the tank would continue to shed small pieces of foam and that additional modifications are planned to eliminate the most hazardous areas.

"We need to fly this vehicle to make sure we've done the first change right," he said.

Managers plan to meet next week to review wind tunnel test data and other analysis and determine if the newly designed tank will hold up during the supersonic climb to orbit.

"There is a lot of work we have to do to make sure we're safe to go fly," Hale said.

NASA, the U.S. space agency, has spent nearly $1.3 billion on vehicle and program safety upgrades since the Columbia disaster.