Image: Launch
In this image of Challenger's liftoff, a black puff of smoke can be seen issuing from the lower half of a solid rocket booster. The puff was a signal that an insulating O-ring had failed.
By Correspondent
NBC News

At the moment of solid rocket ignition, something sinister happened. Barely apparent beside the opening fiery blast, a puff of black smoke spat forth from the lower joint of the right booster. Almost as quickly as it appeared, it was gone. Much later, examination of every frame of film and every inch of videotape would reveal that the smoke spewed forth from a sudden, tiny gap. It was a death warrant.

The long Florida cold had robbed the critical O-ring of its ability to flex, to expand and seal immediately. What was so necessary to be malleable was now hard, almost brittle.

When the joint of the booster rotated, it created a tiny but critical gap. But the stiffened O-ring failed to expand, failed to seal the gap.

Searing gases rammed through and rushed past the primary seal. For 2 1/2 seconds, black smoke jetted out. Then, instantly, it vanished. For within the curving flanks of the rocket, aluminum oxide particles created by the burning fuel miraculously plugged the leak in the joint before flame itself could escape.

Unaware they were now in mortal danger, the astronauts waxed enthusiastic, shouting with excitement as Challenger hammered its way higher and higher.

“Go, you mother!” Mike Smith shouted as the shuttle charged ahead, heading faster and faster into space.

“LVLH,” Judy Resnik announced, reminding the two pilots of a cockpit switch change.

“Ohhhkaaaaay,” Dick Scobee confirmed, grinning.

Sound and fury
Sound and fury enveloped the press site. Tables shook, the press bleachers vibrated from the punching thunder overhead. Windows rattled, floors rumbled as if in an earthquake. Outside the windows, red became orange, leaving behind a dazzling trail of golden fire. But this was expected, the familiar signature of a huge shuttle rejecting the earth.

It was a slow-motion nuclear fireball swallowing everything within reach, then howling up and away, disdainful of any attempt to hold back such power.

No matter how many of these shattering launches you had seen, no matter how many times you had felt the body-shaking impact, the shock waves rippling your clothes like sudden strong wind gusts, you never felt at ease.

You never took human rocket flight for granted. You sweated out every second of a launch, prayed it would go as planned.

Veteran space reporter Mary Bubb of the Reuters News Agency, sat with tightened fists, teeth clenched. She tilted her head slowly to keep the climbing spaceplane with its attached rockets in clear view. Unthinking, she groped for the hand of the reporter seated at her side.

Bubb had been ill for months, but she was dedicated, undaunted by her ailing body. She would never be absent for any launch; especially a shuttle. But this time was different. It was not a chill of the morning’s freeze that swept her body.

“I’m afraid,” she said, her voice barely audible over the battering vibrations and crackling roar. “I’m afraid for them.”

Howling winds
Outside, the wind continued to howl, blowing horizontally with a speed of 84 miles per hour — some of the fiercest winds ever recorded for a shuttle ascent.

Challenger accelerated swiftly into the area of Max Q — maximum aerodynamic stress — where its great speed created shock waves from the resisting air through which it must fly. Inside the shuttle they felt the side loads, felt Challenger meeting the invisible forces.

The shuttle had flown through high winds before. “Yeah,” Dick Scobee announced in recognition of the sudden shaking, “it’s a little hard to see out my window.”

It was a moment with far greater impact than anyone could have known, for this mission carried with it a terrible flaw.

When the side load of the winds smacked into the right booster, they struck an already-weakened rocket. The wind was physical impact. It jarred loose the aluminum oxide particles that at launch had sealed the lower joint where the O-rings had failed. Now the aluminum oxides broke up, spat away from the booster.

There was nothing left to hold back the raging fire and enormous pressure. A tongue of dazzling flame burst through the joint opening, creating a fearsome blowtorch of immense power precisely 58 seconds into the flight.

No one in the crew cabin knew what was happening.

“OK, we’re throttling down,” Scobee called out as he began reducing power of the main engines from 104 percent down to 94 percent, and then reduced power to 65 percent. This would safely diminish the howling thrust behind them as Challenger knifed its way through the combination of powerful shear winds and maximum aerodynamic pressure.

Then they were through and Scobee went back to full power, throttling the engines to full thrust.

“Feel the mother go!” yelled Mike Smith.

“Wooooohoooooo!” another crew member shouted, swept up in the acceleration.

“Thirty-five thousand going through one point five,” Smith reported.

Seven miles high and booming past 1 1/2 times the speed of sound.

“Reading four eight six on mine,” Scobee acknowledged.

Smith agreed with the routine airspeed check. “Yep, that’s what I’ve got, too.”

Fiery blowtorch
Scobee heard Mission Control report his three main engines were again running fine at full throttle. Every instrument reading of the shuttle’s flight and power systems were transmitted automatically, in real time, to Houston.

Mission Control kept up its steady monitoring, telling the pilots everything was “Go!”

No one knew the fiery blowtorch far below the crew cabin was already ripping apart the right booster rocket.

The crew worked smoothly, flawlessly. “Roger, go at throttle up,” reported Scobee. His steady voice amazed a world audience. For the seasoned test pilot this was to Scobee just matter-of-fact language and tone.

Suddenly a sheet of intense flame swept swiftly over Smith’s window.

The pilot’s seat was nearest to the disintegrating booster rocket. In whatever instant of time was available to Smith he knew something terrible was happening.

He had no more than that instant. No more than that infinitesimal moment. Just enough time to utter a single cry, “Uh-oh!”

Next: A hellish fireball

NBC News correspondent Jay Barbree has covered America’s space effort from Cape Canaveral for more than 40 years. This is an updated version of a series that was first published on MSNBC.com in January 1997.

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