Nasa alarm as falling debris problem repeats itself
Nasa has grounded future shuttle flights because a big chunk of insulating foam flew off Discovery’s fuel tank during lift-off as it did with Columbia - but this time apparently missed the spacecraft.
While there are no signs the piece of insulation damaged the spacecraft, Nasa is grounding future shuttle flights until the hazard can be fixed.
“Call it luck or whatever, it didn’t harm the orbiter,” said shuttle programme manager Bill Parsons said last night.
If the foam had broken away earlier in flight, when the atmosphere is thicker increasing the likelihood of impact, it could have caused catastrophic damage to Discovery.
“We think that would have been really bad, so it’s not acceptable,” said Parsons’ deputy, Wayne Hale. But he said early signs were that Discovery was safe for its return home.
A large chunk of foam flew off Discovery’s redesigned external fuel tank just two minutes after what initially looked like a picture-perfect lift-off on Tuesday. But in less than an hour Nasa had spotted images of a mysterious object whirling away from the tank.
Mission managers did not realise what the object was – or how much havoc it would cause to the shuttle program – until yesterday, after reviewing video and images taken by just a few of the 100-plus cameras in place to watch for such dangers.
Officials do not believe the foam hit the shuttle, posing a threat to the seven astronauts when they return to Earth on August 7. But they plan a closer inspection of the spacecraft in the next few days to be sure.
“You have to admit when you’re wrong. We were wrong,” Parsons said. “We need to do some work here, and so we’re telling you right now that the … foam should not have come off. It came off. We’ve got to go do something about that.”
The loss of a chunk of debris, a vexing problem Nasa thought had been fixed, represents a tremendous setback to a space programme that has spent two and a half years and €900m trying to make the 20-year-old shuttles safe to fly.
“We won’t be able to fly again” until the hazard is removed, Parsons said in last night’s briefing.
Engineers believe the foam was 24 to 33 inches long, 10 to 14 inches wide, and just a few inches thick, only somewhat smaller than the 1.67lb chunk that smashed into Columbia’s left wing during lift-off in 2003.
The plate-sized hole let in superheated gases that caused the shuttle to break up on its return to Earth.
Discovery’s astronauts were told of the foam loss before going to sleep yesterday.
Parsons stressed that Discovery’s 12-day mission was a test flight designed to check the safety of future shuttle missions. He refused to give up on the spacecraft that was designed in the 1970s.
Imagery experts and engineers expect to know by this evening whether the gouge left on Discovery by the missing piece of tile needs a second look. The astronauts have a 100ft laser-tipped crane on board that could determine precisely how deep the gouge is.
If Nasa decides to use its new inspection tool to get a 3-D view of the tile damage, the astronauts will examine the spot tomorrow, a day after docking with the international space station.
Yesterday, Discovery’s astronauts spent nearly six hours using the boom to inspect the spacecraft’s wings and nose cap for launch damage. The wings and nose are protected by reinforced carbon panels capable of taking the brunt of the searing re-entry heat.
Hale said the laser inspection turned up nothing alarming, but the analysis was continuing.
