In an eerie portent of the events that ultimately doomed Space Shuttle Columbia, an article from Spaceflight Today reveals that in 1988, booster insulation debris caused extensive tile damage to Atlantis that jeopardized the safety of her crew.
The article by Jim Harwood for CBS News tells the harrowing story of how a debris strike, not unlike the one that destroyed Shuttle Columbia in 2003, tore through a significant section of insulating tiles on the right hand side of the orbiter:
But as it turned out, the damage was, in fact, extensive. More than 700 heat shield tiles were damaged. One tile on the shuttle’s belly near the nose was completely missing and the underlying metal – a thick mounting plate that helped anchor an antenna – was partially melted. In a slightly different location, the missing tile could have resulted in a catastrophic burn through.
“As I moved the arm lower the camera picked up streaks of white,” he wrote in “Riding Rockets.” “There was no mistaking what they were. … As I continued to drop the arm lower we could see that at least one tile had been completely blasted from the fuselage. The white streaking grew thicker and faded aft beyond the view of the camera. It appeared that hundreds of tiles had been damaged and the scars extended outboard toward the carbon-composite panels on the leading edge of the wing. Had one of those been penetrated? If so, se were dead men floating.”
Despite grave misgivings about the condition of Atlantis, security concerns over the then-secret DOD mission prevented NASA Mission Control from properly assessing the situation:
Because the mission was classified, no pictures or television were being downlinked, even to mission control. When the decision was made to send down TV images of the tile damage, the video had to be encrypted.”
“So we send them secure TV,” Gibson said. “The problem with secure TV is, it takes a frame, it encrypts it, it ships that frame, it takes the next frame, it encrypts it, it ships the next one, so you get a frame about every three seconds.”
While the astronauts beamed down the images, Gibson was thinking the worse.
“I think the words ‘we’re in deep doo doo’ were said in the cockpit, this could be a problem, guys, you know? This looks bad. Now you know, I didn’t really think at that instant, yep, we’re as good as dead, write our wills and all that stuff. But I did look at it and say ‘holy smokes, we are going to die’ to myself.'”
The astronauts anxiously waited for mission control’s assessment. And they were stunned when the ground called back.
“We’ve looked at the images and mechanical says it’s not a problem,” the mission control CAPCOM said, according to Mullane. “The damage isn’t that severe.”
“We couldn’t believe what we were hearing,” Mullane wrote. “MCC was blowing us off.”
“I knew that what would happen was, if we started to burn through we would change the drag on that wing,” he said, “which is exactly what happened to Columbia. We would change the drag on the right wing and what we’d see happening is, we’d start seeing right elevon trim, you’d start seeing right aileron, if you will, trim, which means putting down the left elevon, moving the left elevon down.
“I knew we would start developing a split (between right and left wing elevon positions) if we had excessive drag over on the right side. The automatic system would try to trim it out with the elevons. That is one of the things we always watched on re-entry anyhow, because … if you had half a degree of trim, something was wrong, you had a bunch of something going on if you had even half a degree. Normally, you wouldn’t see even a quarter of a degree of difference on the thing.
“So I knew that that’s what I was going to see if it started to go,” Gibson said. “And therefore, that told me that I’d have at least 60 seconds to tell mission control what I thought of their analysis.”
Luckily, the story has a happy ending. The Atlantis landed safely, NASA saw the error of its ways, and they established new procedures that prevented another debris strike from threatening the safety of an orbiter and its crew. Oh wait, they didn’t.
HT to Bad Astronomy