The Challenger Shuttle Tragedy, 20 Years Later

RENEE MONTAGNE, Host:

Twenty years ago today, the space shuttle Challenger sat ready on the launch pad at the Kennedy Space Center in Florida. The mission was to be the 25th flight of the shuttle program. Seven crewmembers waited, including schoolteacher, Christa McAuliffe. The next day, the shuttle broke apart seconds after lift off. The accident shook the Space Agency and its confidence. NPR's David Kestenbaum reports that in some ways, NASA is still recovering.

MONTAGNE: 36 a.m., the crew was strapped in; and after a delay to make sure the ice had melted, the launch team gave the go ahead, and Challenger muscled its way into the air. Soon it was moving faster than the speed of sound.

Film analyzed later would show that just before the accident, a small fiery plume could be seen on the side of the right solid rocket booster. In mission control, controllers looked at their monitors and saw an odd shaped cloud where the shuttle had been.

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UNIDENTIFIED MAN: Flight controllers here, looking very carefully at the situation. Obviously, a major malfunction.

: The two solid rocket boosters continued on, mindless and untethered. Ground controllers ordered them to self-destruct. That night, President Reagan was scheduled to give his State of the Union Address. He canceled those plans and instead spoke from the Oval Office.

RONALD REAGAN: We will never forget them nor the last time we saw them, this morning, as they prepared for their journey and waved goodbye and slipped the surly bonds of earth to touch the face of God.

: Reagan created a commission to investigate the accident. It took a while to sort out what had gone wrong that day. Then at one meeting, physicist Richard Feynman dumped a piece of material into a glass of ice water. It was the same material used as an O-ring seal on the shuttle. It kept hot gases from leaking through a joint. And as he demonstrated, it didn't work as well in the cold.

RICHARD FEYNMAN: Well, I took this stuff that I got out of your seal and I put it in ice water, and I discovered that when you put some pressure on it, it doesn't stretch back; it stays the same dimension. In other words, for a few seconds at least, and more seconds than that, there's no resilience in this particular material when it's at a temperature of 32 degrees. I believe that has some significance for our problem.

: It turns out that engineers had worried about the O-rings. There had been a history of problems. But their concerns had been ignored or overruled. Seventeen years later, the Space Shuttle Columbia broke apart over Texas. A piece of insulating foam had punched a whole in its wing during launch. Again, a panel investigated; again, they said the problem had been there all along, but its significance hadn't been appreciated.

There's been only one flight since Columbia, and despite NASA's best efforts, there were snags. A large piece of insulating foam fell off during launch and tumbled, harmlessly it turns out, past the shuttle's wing. Michael Griffin, NASA's administrator, said the problem would be fixed and the shuttle would fly again.

MICHAEL GRIFFIN: This was the 145th American manned space flight. Compare that with the development of aviation and we're in still the very first stages of learning how to do space flight.

: NASA has three remaining space shuttles. The agency needs about 15 more missions to finish the International Space Station. That is a very ambitious schedule. The plan is to retire the shuttles in just five years.

NASA wants to replace the shuttles with a capsule that rides atop a rocket where nothing can hit it. It's a lot like the old Apollo days. In some ways, it's a less ambitious design, but it's one that seems to anticipate our own inevitable shortcomings.

David Kestenbaum, NPR News.

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