Michael Leinbach - Bringing Columbia Home - The Untold Story of a Lost Space Shuttle and Her Crew

Closer to home, KSC held several events during May and June to thank Kennedy’s workers and their families for their contributions and sacrifices in the recovery and reconstruction efforts.

On May 7, our reconstruction hangar team and their families were the guests of honor at a Florida Manatees minor league baseball game at Space Coast Stadium in Viera. It was important to give our workers some relief. We all needed to blow off some steam—to party and forget about the hangar a little bit. We tailgated in the parking lot before the game. Steve Altemus and his team leaders boiled eight hundred bratwursts in beer and grilled them with red onions. I threw out the game’s opening pitch, which promptly landed in the dirt.

At the end of the evening, our group persuaded Ann Micklos to dance on top of the dugout. Micklos later explained, “To me, this was all part of the grieving process. You needed that big family to get you through this. You’ve got to make a joke when it gets too serious. That’s what got us through—that balance between the two. Because if you didn’t have that balance, we never could have done what we did.”

We held a daylong picnic for KSC’s Columbia teams and their families at KARS Park near Kennedy Space Center on May 30. It was the first time the recovery teams from all of the sites came together after the accident, and it was the first joint event ever held for both the recovery and reconstruction efforts. The party was a blowout of mammoth proportions. Hundreds of workers and their families attended. Many stayed overnight in RVs. Jim Comer and his helpers shucked 120 cases of corn and cooked 100 pounds of shrimp. Our finest rocket engineers designed and built an “atomic slip-and-slide” for the kids, and many adults found their way onto it as well. Water-gun fights and volleyball games helped people loosen up and celebrate their hard work and friendships.

The exclamation point that provided closure to the accident investigation was independent of the reconstruction and data teams. NASA and the CAIB wanted to simulate as accurately as possible the launch debris strike on Columbia . To do this, they needed to shoot foam insulation into samples of the shuttle’s silica tile and reinforced carbon-carbon wing panels at the speed and angles at which the foam would have collided with the ship during the impact.

Two days after the accident, the CAIB and NASA contacted the Southwest Research Institute (SwRI) near San Antonio for assistance in the accident investigation. SwRI had conducted previous studies for NASA on the effects of impacts of much smaller pieces of foam, cork insulation, and ice on shuttle tiles. The Institute was a logical choice for performing the tests that would simulate the conditions of the Columbia accident.

Investigators wanted incontrovertible proof that foam from the external tank was capable of inflicting mortal damage on the shuttle’s thermal protection system. That foam could damage the wing seemed counterintuitive on many levels. How could a piece of lightweight insulation—about the density of Styrofoam and weighing less than two pounds—fall off the tank and cause that kind of damage? And wasn’t it traveling at about the same speed as the shuttle?

In fact, analysis showed a significant velocity difference between the shuttle and the foam at the time of impact. NASA estimated that the shuttle was traveling faster than 1,500 mph—and accelerating—when the foam fell off the tank. After falling off, the foam immediately and rapidly decelerated due to air resistance. The block slowed to about 1,000 mph in the 0.2 seconds between when it came off the tank and when the shuttle’s wing impacted the foam. The relative difference in speeds between the shuttle and foam was therefore more than 500 mph. [5] CAIB Report , 61.

The piece of foam that struck Columbia was four hundred times larger than the pieces tested previously by SwRI. Using a special compressed air cannon, SwRI planned to simulate the collision by firing foam blocks at more than 500 mph into samples of shuttle tiles and wing leading edge panels. High-speed cameras photographed the test firings and impacts, and over two hundred sensors measured the effects of the collisions.

By the time the equipment and procedures were ready for the first test on the landing gear door, the investigation had already narrowed its focus to the wing’s leading edge as the impact area. SwRI ran its test anyway using a landing gear door—one borrowed from Enterprise [6] Jim Comer noted that Enterprise was at the time being prepared for exhibit in the Udvar-Hazy Center of the Smithsonian’s National Air and Space Museum. Pam Melroy and Comer traveled to Washington and negotiated with museum director Gen. J. R. “Jack” Dailey for a loan of the leading edge panels and the landing gear door. As a side note, Enterprise did not have thermal tiles, since it was not intended to fly in space. NASA glued tiles to Enterprise ’s landing gear door to simulate an operational shuttle for these tests. and subsequently covered with silica tiles—to check out the test equipment and processes. As expected, a grazing impact of foam, akin to what would have occurred in flight had the foam hit the underside of the wing, caused only minor damage to the tiles on the landing gear door.

Space shuttle wing leading edge panels are large, expensive, and made to order. The reinforced carbon-carbon (RCC) material also wears and becomes more brittle over time, so SwRI could not use newly manufactured panels to get an accurate assessment of potential damage in its impact tests. The test panels would have to come from the wings of Discovery and Atlantis , the two orbiters that had flown about as many times as Columbia . NASA decided to test the process first using fiberglass wing panels from Enterprise , which was not designed to fly in space.

Several test shots at Enterprise ’s fiberglass panels—which were stronger than the RCC panels on the flight-worthy shuttles—produced scuff marks from the foam blocks, but no breakage. After getting its process and equipment calibrated, SwRI was now ready to try the tests with the space-flown RCC panels.

First, a foam block was fired at panel 6 from Discovery . The impact created a crack nearly six inches long in a rib supporting the leading edge, and it moved the panel enough to create a small gap in the T-seal between panels 6 and 7. This test proved that foam could damage the RCC material. However, the damage incurred in this test would not have been severe enough to create the burn-through seen on Columbia . NASA estimated a hole of at least ten inches in diameter would have been needed for the wing to ingest a plasma stream large enough to create the damage seen in Columbia ’s debris.

The next test target was panel 8, which had flown twenty-six times on Atlantis . Evidence from the reconstructed debris and the OEX recorder indicated that panel 8 was the site of the impact on Columbia ’s wing.

At the test on Monday, July 7, the impact from the foam block blew a huge hole through the panel about sixteen inches by sixteen inches across, created several other cracks, and caused the T-seal to fail between panels 8 and 9. This was entirely consistent with the type of damage postulated to have caused Columbia ’s demise.

Witnesses were incredulous, but the evidence was incontrovertible. NASA now had the smoking gun matching the fatal wound on Columbia . The test silenced lingering doubts that a foam strike alone was sufficient to damage the wing and doom the ship.

In the late spring, we invited the families of the STS-107 crew to visit the reconstruction hangar and see Columbia ’s debris. Our staff prepared carefully for the visit. We wanted everything to be as perfect as possible for the families. [7] Interview with Steve Altemus.