Legendary commander tells story of shuttle's close call (1988 Atlantis heat tile damage)

NASA, Spaceflight Now, CBS ^ | March 27, 2009 | William Harwood

[bd476]

Legendary commander tells story of shuttle's close call

BY WILLIAM HARWOOD

STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: March 27, 2009

The exhaustive attention NASA now devotes to making sure shuttle heat shields are damage-free and safe for re-entry is a direct result of the 2003 Columbia disaster. But a blacked-out military flight 21 years ago still stands out as a warning to astronauts, engineers and managers, a frightening "close call" that had the potential to bring the shuttle program to an early end.

It was that close.

Extensive tile damage is visible on the ship's underside during landing on Dec. 6, 1988. Credit: NASA
 

"I will never forget, we hung the (robot) arm over the right wing, we panned it to the (damage) location and took a look and I said to myself, 'we are going to die,'" recalled legendary shuttle commander Robert "Hoot" Gibson. "There was so much damage. I looked at that stuff and I said, 'oh, holy smokes, this looks horrible, this looks awful.'"

He was seeing the worst tile damage any shuttle had ever experienced.

But a perfect storm of poor communications, caused in part by military restrictions that prevented the crew from downlinking clear images showing scores of chipped and broken tiles, ultimately resulted in a flawed analysis on the ground that indicated the crew had nothing to worry about. Flight controllers were not convinced the shuttle was seriously damaged at all. Some engineers apparently believed the astronauts had been misled by poor lighting conditions and grainy TV images.

The crew knew better. The images were crystal clear on the shuttle, and definitely alarming. But the astronauts reluctantly accepted the judgment of mission control and went on about their business. The mission still stands out as an example of how assumptions, poor communications and an unwillingness to challenge authority can put people in danger in high-risk endeavors like spaceflight.

"There was a big failure to communicate," Gibson recalled in an interview this week. "When you talk about crew resource management, or cockpit resource management or any of that resource management stuff, it's real easy to be talking and not communicating. In order to be really communicating, you've got to say 'here is what's on my mind.' I think I was doing that to a major degree, but maybe I fell short by not arguing with them. But they really did not tell us what was on their minds."

Gibson, a former Navy test pilot, "Top Gun" graduate, chief astronaut and veteran of five shuttle missions, was at the controls when the shuttle Atlantis blasted off Dec. 2, 1988, on the second post-Challenger mission. Carrying a top-secret spy satellite, the mission was fully classified and all communications with the astronauts were blacked out.

Atlantis was launched on Dec. 2, 1988. Credit: NASA

But 85 seconds after launch, a piece of insulation on the tip of the shuttle's right-side solid-fuel booster broke away and struck Atlantis' right side. The impact was not noted on NASA television at the time and after landing, NASA engineers said that while the shuttle had suffered more tile damage than usual, "it isn't something that's of a major concern."

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.

It was the most extensive shuttle heat shield damage ever recorded until Columbia took off on its final voyage.

Years later, Gibson would be asked to brief the Columbia Accident Investigation Board about his experiences aboard Atlantis and as the tale was told, "their jaws dropped," he said.

Crewmate Mike Mullane devoted a chapter to the mission in his book "Riding Rockets: The Outrageous Tales of a Space Shuttle Astronaut," writing that as entry approached, "the anxiety was exhausting."

"I finally gave in to Hoot's solution. The day before (entry), as he floated to the windows to do some sightseeing, he said, 'no reason to die all tensed up.' I would do my best to relax and enjoy the sights."

Even so, he wrote, during Atlantis' descent "I had visions of molten aluminum being smeared backward like rain on a windshield."

Gibson, Mullane, pilot Guy Gardner, Jerry Ross and William Shepherd had no idea Atlantis had been hit during ascent. It was not until the next day that mission control called up with an unusual request. The crew was asked to use Atlantis' robot arm to inspect the shuttle's heat shield on the ship's right side.

Damage to Atlantis' tiles was wide-spread. Credit: NASA
See larger image here
 

Mullane, the arm operator, dutifully carried out a procedure to maneuver the arm into position so a black-and-white television camera on the end could "see" the tiles in question.

"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."

Gibson, who flew for Southwest Airlines for years after retiring from NASA, recalled his impressions as the images snapped onto TV monitors in Atlantis' cockpit and his immediate "we are going to die" reaction.

"So I get on the mic and I call Houston and I tell them, Houston, we are seeing a whole lot of damage on the right wing, in the chine area and back on the right wing in the tiles. ... The ground comes back and says well, you know what, we need you guys to send us secure TV."

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.

The crew in space: Gibson, Mullane, Ross, Shepherd and Gardner. Credit: NASA
 

"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."

Gibson then chimed in, saying "Houston, Mike is right. We're seeing a lot of damage."

But mission control repeated the engineering assessment that the damage was not that severe.

"I'm just perplexed at this point," Gibson said. "Because I'd never seen anything like this before. Never seen anything even close, and I'd been there since before day one. ... He came back and he said 'Hoot, they've looked at it and they've determined that it's not any worse than what we've seen on other flights.' And I am just perplexed. I think I was silent for maybe 30 seconds, because I didn't know what to say. And I came back and I said something to the effect that well, all right. It looks pretty bad to us, but you guys are the experts, so OK.

"And I honestly believed at that point, the rest of my crew said, 'Oh, OK, great, no problem.' I did not. I did not believe them. I didn't want to argue with them, I didn't want to have a long drawn-out argument over the air, but I suppose I was probably remiss to some degree because I didn't quiz them some more."

Of course, it's not clear what, if anything, could have been done if engineers had realized the severity of the problem. There were no tile repair tools on board the shuttle and no techniques for even getting an astronaut to the damage site. Changes to the shuttle's re-entry orientation and trajectory could have been attempted, Gibson said, but whether anything like that would have worked is an unknown.

The real issue for Gibson - and the same issue was faced Columbia's crew - was that no one took the extra step to make sure the problem was fully resolved.

"NASA does amazing things when they've got their back against the wall," he said. "Like Apollo 13. I've seen us work out some really dramatic things in some of the missions when we had on-orbit problems and we did in-flight maintenance and things like that. You never know what you could have done because you didn't try."

Metal under a missing heat-shield tile was partially melted. Credit: NASA
 

Hoping for the best, Gibson and Gardner fired Atlantis' twin braking rockets on Dec. 6 to begin the shuttle's fiery descent to a landing at Edwards Air Force Base, Calif. The astronauts did not discuss any fears they may have had, but as the shuttle fell into the discernible atmosphere, Gibson kept his eyes on a gauge that showed how much the elevons at the back of each wing were deflected.

"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."

But as it turned out, Atlantis did not suffer a burn through and Gibson guided the shuttle to a smooth landing at Edwards. Gathered on the runway after touchdown, the astronauts, engineers and NASA managers were astonished at what they saw.

"The damage was much worse than any of us had expected," Mullane wrote. "Technicians would eventually count 700 damaged tiles extending along half of Atlantis's length. It was by far the greatest heat shield damage recorded to date."

The astronauts and officials inspect the damage on the runway. Credit: NASA
 

During debriefing after the mission, Gibson finally learned why the engineering community had not taken the crew's descriptions of the damage more seriously.

"Their conclusion, which they did not pass back to us, was 'oh, you know what? That's not tile damage, those are just lights and shadows we're seeing in this video.' So in other words, the resolution on the encrypted video was that bad that they based a conclusion on it that was in gross error. ... If I had said hey, I think this is important enough for us to break the encryption and send you guys clear video, oh, it would have been pandemonium down there at DOD. But in hindsight, oh man, that's what we should have done. Because they were drawing an incorrect conclusion from it and they were not telling us what their conclusion was."

Wayne Hale, a veteran ascent-entry flight director and former shuttle program manager at the Johnson Space Center, agreed engineers were caught off guard by the severity of the damage when they finally saw the shuttle on the runway.

"We were struggling in those days to try to maintain the security classification, so on and so forth," Hale said in a telephone interview. "When the crew reported they saw this stuff, we had a long negotiation as I recall with the customer to say well, can we look at the TV? Because we weren't supposed to see any TV from on orbit. (They said) absolutely not. Could we look at the bottom side of the shuttle? That was the agreement, that we could, but we used this special slow-scan TV. And it was grainy.

"People were concerned, I suppose, but not nearly at the level that we would be today. And STS-27 has always been the worst tile damage flight we ever had. It set all the reference marks. It's interesting that there is enough capability in that thermal protection system to take that kind of damage and survive."

Reflecting on what Hale agreed "was a real close call," Gibson said he believes NASA came close to losing the crew and along with it, the shuttle program. STS-27 was only the second flight after the Challenger disaster and unlike Columbia, the shuttle re-entered over the Pacific Ocean for a descent to Edwards. Had Atlantis been lost, most of the wreckage would have sunk and engineers might never have discovered the cause.

"We had spent all that money and all that time rebuilding and revamping and we launched one successful mission, we lost the very next one," Gibson said. "I think the Congress would have said OK, that's the end guys, we just don't need to do this again. I think that just would have been the end of it."

[bd476]

NonValueAdded wrote: "Did’ja all catch that they knew the instrumentation signature of burn-through and 'that is one of the things we always watched on re-entry anyhow.'

Yes, I sure did. Knowledge of all possible contingencies doesn't predict their occurrence. Yet it still had to have been for even a Top-Gun Graduate/Navy Test Pilot such as Commander Gibson, one extremely white-knuckled re-entry.

If they had not successfully re-entered and landed at Edwards AFB, the entire crew would have been lost; the Shuttle would have been impossible to retrieve from the Pacific Ocean; no one would have known about the extensive damage to Atlantis' heat tiles; and Atlantis being the second Shuttle mission following the Shuttle Challenger disaster, without a doubt the entire Space Shuttle program would have ended.

[YOUGOTIT]

While the debris investigation went on and the thermal protection material for the forward skirt, frustum, nose cap and aft skirt were changed on the next flight (March 13, 1989, STS - 29R), (new material that never again came off, that had been in work for over three years because of the inability of the old material, that caused damage to many of the heat tiles (on STS - 28R), to stay on, it was thought by the engineers at the time it came off due to impact with the ocean and not during flight), the people refused (although several individuals stated it was a problem and should be fixed), at that time, to believe that the thermal protection material of the fuel tank, due to its weightless nature, also caused damage and was a danger.

[bd476]

BerryDingle wrote: "Don’t underestimate the ignorance of NASA, they’re trying to sell us global warming right now."

There's at least one politician in every group of people, including scientists. However, I wouldn't worry about the few politically motivated (read $$) scientists being able to influence all scientists everywhere.

[sefarkas]

It seems that the location of the tile failures is significant. In spite of the graphic description of damage and the hyperbole of the story, the engineers were correct and Atlantis landed as expected.

[TXnMA]

I have seen a dramatic photo of a 3" cube of tile material that was heated red hot in the center, and it was being held by opposite corners betwen a man's thumb and middle finger -- and the interior was still visibly glowing red hot.

This is the closest thing I could find via a quick search:

[JohnBovenmyer]

Am I reading your and the original posts correctly that the insulating foam that came loose on this mission to damage the tiles is not the same stuff as what was changed, “to protect the ozone layer” to the material that eventually brought down Columbia? If this were the THAT foam, before the greenie change, than it would tend to disprove the theory of some that that foam change, and thus environmentalist concerns, was at least partially to blame for the Columbia disaster.

[bd476]

Gorzaloon wrote: " 'These tiles are super hi tech ceramics of some kind?'

Not really..they were even selling off spec ones for industrial use in the late 80's-90's. We had some at work. They were just a glorified zirconia fiberglass-like refractory wool molded and fired into lightweight "Fire Bricks"."

Zirconium, nor its impure oxide Zirconia are not used in the manufacture of the Shuttle tiles, according to NASA.

Instead the High-Temperature Reusuable Surface Insulation Tiles (HRSI) are made of nearly pure silica.

High-Temperature Reusable Surface Insulation Tiles

"The HRSI tiles are made of a low-density, high-purity silica 99.8-percent amorphous fiber (fibers derived from common sand, 1 to 2 mils thick) insulation that is made rigid by ceramic bonding. Because 90 percent of the tile is void and the remaining 10 percent is material, the tile weighs approximately 9 pounds per cubic foot. A slurry containing fibers mixed with water is frame-cast to form soft, porous blocks to which a collodial silica binder solution is added. When it is sintered, a rigid block is produced that is cut into quarters and then machined to the precise dimensions required for individual tiles.

HRSI tiles vary in thickness from 1 inch to 5 inches. The variable thickness is determined by the heat load encountered during entry. Generally, the HRSI tiles are thicker at the forward areas of the orbiter and thinner toward the aft end. Except for closeout areas, the HRSI tiles are nominally 6- by 6-inch squares. The HRSI tiles vary in sizes and shapes in the closeout areas on the orbiter. The HRSI tiles withstand on-orbit cold soak conditions, repeated heating and cooling thermal shock and extreme acoustic environments (165 decibels) at launch..."

NASA: High-Temperature Reusable Surface Insulation Tiles



The space shuttle engine contains a copper-silver-zirconium alloy:

"The space shuttle engine, for example, uses a copper-silver-zirconium alloy..."

Structural Materials in Aerospace Systems

[bd476]

That's a cool errh, lol, interesting demonstration. Thanks for posting the photo, TXnMA!

[bd476]

sefarkas wrote: "It seems that the location of the tile failures is significant. In spite of the graphic description of damage and the hyperbole of the story, the engineers were correct and Atlantis landed as expected."

If you had read the entire story, you would have noted that NASA engineers were in fact surprised by the extent of damage to the heat tiles.

If you can't bother to read an entire story, go argue with someone else, or better, and with all due respect to Commander Aldrin, just Buzz off.

[Grammy]

I believe they are ceramic in some form or other. Mr G’s father was a scientist (ceramic engineer) and helped develop them.

[mvpel]

Here's an excerpt from The Cognitive Style of PowerPoint: How Pitching Out Corrupts Within

[buccaneer81]

That’s frightening. That article should be required reading in college, especially in the sciences. Thanks.

[bd476]

XBob wrote: "good catch bd. I saw this one close up, but it was not the closest safe landing nearly resulting in disaster, there was one worse that I saw."

Thanks, XBob. That would have been frightening to see. Which one was it?

[LiberConservative]

... tile assembly is bonded to the orbiter structure by an RTV process ... the RTV silicon adhesive is applied to the orbiter surface in a layer approximately 0.008 inch thick.

Society would collapse if we banned RTV and duct tape.

[sefarkas]

I read the entire story with great interest. The hyperbole was wide spread. Your protests not withstanding, Atlantis landed that day as expected, all of the crew safe & sound. Go back to your NASCAR race and wait for the crash. Arrogant assuming remarks like yours bode ill for the FR community.

[anymouse]

I wonder how this crew sleeps at night, knowing that if they had spoke up louder after their close call, that their fellow astronauts, the Columbia crew would still be alive today?

Even if it was a highly secret military mission, there were channels for providing this crucial mission safety info. back to shuttle engineering and mission operations, so they could take corrective action for future missions. It wouldn't necessarily have prevented a future catastrophic incident, but shutting up about a clear mission safety issue should never be acceptable.

But sadly I am all too aware of the tyranny at NASA that would keep this crew from passing on this safety info. even to fellow astronauts. And guess what, George Abby, that tyrant of NASA JSC at that time is now advising Obama on space policy. So look for more fear and loathing at NASA.

[SunkenCiv]

Robert "Hoot" Gibson

He was always more popular than his flatulent colleague, Paul "Toot" Mifinger.

[XBob]

“Thanks, XBob. That would have been frightening to see. Which one was it?”

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Sorry, I don’t remember which particular flight, however, what I do remember is that it was in late 1987 or early 1988, on one of the orbiters which lost some tiles right on the rear edge of the left wing, which cover the elevon control shaft. This is a solid heavy duty shaft about 3+ inches in diameter, which controls the movement of the elevon. 2 or 3 tiles were lost, and the shaft was burned through (like with a welding torch) until there was only about 3/4 inch of that 3+” diameter left. It was like a shark had taken a bite out of the shaft, and it was barely connected.

I think subsequently they made a modification where they put some special metal plates over the shaft and under these tiles, for critical area protection.

[XBob]

25 - “have seen a dramatic photo of a 3” cube of tile material that was heated red hot in the center, and it was being held by opposite corners betwen a man’s thumb and middle finger — and the interior was still visibly glowing red hot.”

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I have personally done this. It is pretty neat, and you have to grip the foam well, as it is so light.