The Space Shuttle Discovery will launch on July 1 despite concerns of safety and engineering officials that further redesign work should be performed before the space commuter goes aloft again, NASA announced.

This would be the second flight since Space Shuttle Columbia was lost in 2003.

A piece of insulating foam broke off from the external tank and damaged the leading edge of the shuttle wing. During reentry Feb. 1, 2003, that opening permitted hot gases of the atmosphere to enter the wing, causing structural failure of the shuttle. The crew of seven was lost in a fiery streak across the sky.

NASA leaders said in a briefing Saturday that substantial work in redesigning Discovery already has been performed, such as removal of large amounts of foam. But safety and engineering officials urged further redesigns before they would feel Discovery was safe enough to fly, although ultimately they assented to the liftoff.

Their point of concern centers on foam applied to components on the external tank called ice frost ramps. Because the tank is filled with super-cold liquid oxygen, insulating foam must be applied, so as to prevent formation of ice that might break off and harm the shuttle.

But NASA leaders approved the Discovery flight, saying that a Columbia-style loss of the crew isn’t possible this time.

That’s because of multiple safety steps taken since 2003, they said:

First, large amounts of foam in critical areas have been removed from the shuttle system, which includes the Discovery orbiter space/air craft in which the crew rides; the propulsion tank containing liquid oxygen; and two solid-propellant booster tanks.

While NASA still expects some foam to break off during the ascent flight, it is likely to be much smaller pieces than the hunk of foam that caused the fatal damage to Columbia.

That is where the disagreement at NASA centers, on the potential for foam loss.

But NASA leaders such as administrator Michael Griffin, in giving the green light to permit Discovery to fly to the International Space Station (ISS), also are relying on other safety moves taken since the Columbia mission.

For example, upon achieving orbit, robotic arms with cameras will scan the exterior of Discovery extensively and repeatedly, to spot any damage that might have occurred during the ascent. The greatest attention will focus on the areas that would incur the highest heat during reentry. (Please see Space & Missile Defense Report, Monday, June 12, 2003, stories on pages 1 and 6.)

If damage is discovered, the Discovery crew can use the ISS as a safe haven until they can hitch a ride home on another spaceship that would voyage to the ISS later.

Further, there is a possibility that the Discovery crew could use a spacewalk to perform repairs of any damage.

NASA leaders wish to press ahead with shuttle flights, even though another shuttle disaster would end the program, so as to finish ISS construction work and provide service to the space station. Shuttles will be replaced in the next decade with the Crew Exploration Vehicle, which hopefully won’t suffer such problems.

The window for flight is July 1-July 19.