Shuttle gets permission to land

No fourth spacewalk

NASA has given the Shuttle Discovery the all-clear to land as scheduled on Monday next week, despite lingering safety concerns.

As well as the well-publicised falling foam and protruding gap-fillers, engineers have been worried that a torn section of thermal insulation blanket would need repairing before the Shuttle could make its way back to Earth. The concern was that the blanket could tear off during re-entry and collide with the Shuttle.

After plenty of wind-tunnel tests on the ground, the consensus among NASA personnel now is that the return flight will be as safe as possible, although shuttle deputy programme manager Wayne Hale offered no guarantees: the tunnel-tests revealed that tiny pieces of the insulating blanket could tear off during reentry, and that there was a 1.5 per cent chance that the whole section would come loose.

"I will not tell you that it is zero risk," he said in a Guardian report. "It is the lowest risk, the best choice and the unanimous decision of the engineers and the management team that we should re-enter as is." ®

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