“the ground wasn't seeing what we were seeing"
Mike Mullane explains how the Space Shuttle Atlantis had a close call in 1988 when its heat shielding was substantially damaged during liftoff
What happened?
Just 85 seconds after launch, Space Shuttle Atlantis was struck by a piece of insulation which had come off the right-hand solid rocket booster nose cap. More than 700 heat shield tiles were damaged, and one tile was missing entirely.
What mission were they on?
The problem struck on STS-27, which was only the third flight of Space Shuttle Atlantis and launched on 2 December 1988. “We never saw anything happen during launch. We only found out there was a potential problem when mission control informed us later, saying they had looked at the cameras and had seen something detach from the shuttle. We know now that a piece of the nose of the rocket side booster had broken off and flown back, hitting the heat shield tiles. But all we were concerned about at the time was how much damage had been caused and what effect that would have on the mission.
“Mission control told us to use the space shuttle's robot arm to take a look at the craft's exterior. the arm had a camera on the end of it and, as the robot arm operator, I was to bend this thing over and take a look at the heat shield. When we looked, we could see that there appeared to be significant damage to the shuttle.
“this leapt out at us because those tiles are normally black. they have a very thin outer black coating, but this had been stripped off. underneath is styrofoam and very white – and this clearly revealed itself. We could see white streaks everywhere which showed the extent of the damage, and it trailed beyond what the camera could view. Hundreds of tiles had been damaged.
“there was one tile that was missing in a very high temperature point. It would probably see about 2,500 degrees fahrenheit [1,371 degrees Celsius] on re-entry. It was certainly cause for concern, and we told the ground what we were seeing and that it looked serious. We worried that the leading edges of the wing would be affected because they're subjected to intense heat right on re-entry through Earth's atmosphere.
“But it turned out that the ground wasn't seeing what we were seeing. since we were on a military mission there was a fear that the images would reveal something secret, and the military did not want any of the data on the video going down to the ground without first going through them. Due to that there was some apparent degradation of the video as it passed through to mission control. Yet we were unaware of this convoluted path.
“I only heard about all of this after we got back and, in fairness to mission control, they were just not able to see the severity of the damage that we were seeing. But on board, we were a little bit confused initially by mission control’s reaction. We were surprised that they felt so confident – usually mission control thinks there’s a serious problem and looks into it. so the fact that they didn't follow up with surveys and other data-gathering exercises was kind of surprising to us.
“We thought that mission control was not doing what we expected them to do, and so when we were re-entering I think all of us had some concern in the back of our mind about the damage we had seen.
“I know the commander told me later that he was watching the gauge that showed the levels of deflection in the elevons at the rear of Atlantis' wings. He was looking for signs that one wing was moving left because it was coming apart. When we got back safely and the problem could be looked at properly, there was disbelief. It was much worse than we expected. We were lucky, but miscommunication and poor quality pictures had proven to be problematic."
“When we were re-entering I think all of us had some concern in the back of our mind” Mike Mullane