Foam Continues to Fly - No scheduled changes as shuttle set to launch in July

WASHINGTON, April 28 — NASA has decided to fly the space shuttle Discovery in July without making all potential modifications to its external fuel tank that might reduce damaging foam debris, a move that concerns some agency engineers, officials said today.

Engineers have removed two large sections of insulating foam from the tank and are still evaluating the effects of that action, they said. Work will continue on redesigning or removing all or some of 34 smaller, potentially hazardous foam wedges in the future, but they will fly "as is" on the upcoming flight, they said.

N. Wayne Hale Jr., director of the shuttle program, said in a televised news conference that the decision to curtail further foam modifications before flying again followed a lively discussion among managers at a program meeting at NASA's Marshall Space Flight Center in Alabama. Some argued that NASA not fly before changing the small foam wedges to reduce their shedding potential.

"There was a strong, concerted opinion from several folks that we should wait until we have a good design on these pieces of foam and then change them before we go flying," Mr. Hale said, "That's not without merit and we considered it very strongly.

"But at the end of the day, it is appropriate to make one change at a time with the biggest problem we have, and then work our way to the next situation."

Reducing falling fuel tank debris has been a priority for NASA since the loss of the shuttle Columbia on Feb. 1, 2003. Foam insulation falling from the tank during the launching damaged Columbia's heat shield, causing the destruction of the craft and the deaths of seven astronauts as the ship attempted to return through the atmosphere from a science mission.

When Discovery flew last July on the first mission since Columbia, a greatly reduced but hazardous amount of foam still fell from its redesigned tank during the launching. Afterward, engineers removed more than 37 pounds of foam that formed two air ramps, or deflectors, that protected pressurized fuel lines and a tray guiding cables down the side of the tank, places from which the biggest pieces of foam fell in the last mission.