2:00 a.m.
High up on the 235-foot level at the top of the launch gantry, it was dark, and cold; the wind sang in the girders, and Charlie Stevenson did not like what he saw. The leader of the Kennedy Space Center Ice Team, it was Stevenson’s job to check the shuttle for ice that might prove dangerous during takeoff. His inspection was usually confined to the external tank, which, although insulated with thick blocks of polyurethane foam, became so cold when filled with liquid oxygen and hydrogen that moisture in the humid Florida air often formed a thick rime across its surface.
But when he had arrived at work in the Firing Room soon after midnight, Stevenson discovered a far more threatening problem developing out on Pad 39B. The cameras monitoring the gantry and the mobile platform supporting the shuttle revealed that the plan to protect the plumbing on the launchpad from the freezing weather had backfired. Although the pipes hadn’t burst in the cold, the water trickling through the sprinkler system and the emergency showers and eyewash baths, spilling across the catwalks and cascading down the steel supports of the Fixed Service Structure, had left the pad encrusted in ice. What he found when he and his team arrived to inspect the scene in person was unlike anything he had ever seen before: sheets of ice an inch and a half thick glistened underfoot; the route Dick Scobee and his crew would take along the swing arm in an emergency—from the orbiter hatch to the slidewire escape baskets—was blocked by a dense slick of frozen water. Icicles a foot and a half long, like the pipes of a ghostly organ, dangled from handrails and walkways; they hung from the conduits, the cable trays, and the gratings.
Stevenson feared that, when shaken loose by the violent concussions of Challenger’s launch, the falling icicles could become devastating missiles if they struck the shuttle’s delicate thermal protection tiles—causing damage that would make the spacecraft vulnerable to disaster on reentry. On the radio connecting him to Firing Room 2, he reported his concerns about the planned launch: the ice was dangerous, and growing worse; but if they stopped the water running, the pipes would freeze.
“Then what choices we got?” the Director of Engineering asked.
“Well, I’d say the only choice you got today,” Stevenson said, “is not to go.”
Back in the Launch Control Center, Launch Director Gene Thomas didn’t want to hear it: “Boy, he’s really stretching it,” he said.
Thomas had already been delayed another hour by a computer glitch in the pad fire extinguishing system, moving the launch time back to 10:38 a.m.; if they were to have any chance of getting off the ground later that day, they would have to start filling the external tank with fuel—“tanking”—immediately. He told Stevenson to come back to the Firing Room to discuss their options, while he called in advice from the shuttle design team at Rockwell in California; they’d figure out some way of handling the ice.
The Launch Director gave the order for tanking to begin; the countdown continued.
At 5:00 a.m., Ellison Onizuka’s older brother, Claude, awoke in the Quality Inn on International Drive in Orlando, and began preparing the large group of Ellison’s friends and relatives for the hour-long drive over to the Cape. Claude had flown in from Kona the previous week to help shepherd more than sixty people—his mother, as well as aunts, uncles, cousins, nephews, and his brother’s former scoutmaster Norman Sakata—from Hawaii to the Space Center to watch his brother leave for orbit. Now, for the second day in a row, he had to wrangle six vans full of guests out of bed before dawn for the long trip to the launch site.
At the Ocean Landings condo in Cocoa Beach, it was so early that Alison Smith pretended to be asleep when the phone rang, and her mother answered. It was Mike, calling from the crew dormitory: “We’re not going to be able to launch today,” he said, and asked what they were saying on TV about the weather. Although Jane and the other families would be picked up by NASA as planned and taken over to the Launch Control Center in just a few hours, he was almost certain they would simply be there to witness another postponement; it was just too cold. Mike told his wife he’d already called the Launch Director’s secretary and arranged to change the children’s plane tickets and get them to Houston that afternoon. They would return for another attempt later in the week. “We’re going to come back down here on Thursday,” he assured her.
It was still dark as Marshall Director Bill Lucas and his immediate number two drove through the security checkpoint at the Kennedy Space Center. The bright moon hung low in the sky, and the cold sent the men hurrying from the car, through the sliding doors, and into the marble-floored lobby of the Launch Control Center. Inside, they took their seats among the uppermost tiers of consoles in the double-height space of Firing Room 3, reserved for senior mandarins from NASA.
Confined within an air-conditioned glass box, from here Lucas could look down over the rows of engineers manning consoles beneath him—and, when the moment came to launch, swivel his chair around to take in the view of the pad through the laminated two-story windows behind him, louvered with steel panels to shield them from the sun. Nearby, a color TV raised on an alloy stand also displayed a continuous feed of pictures from NASA Select TV. As he sat down, Lucas was greeted by his managers Larry Mulloy and Stan Reinartz, who gave him a succinct summary of the previous night’s teleconference: the rocket engineers at Thiokol had expressed some concerns about the weather, but had discussed their reservations at length. Eventually, they all agreed there would be no problem.
Mulloy handed Lucas a copy of the late-night fax from the Wasatch plant summarizing the company’s official position—a single page of just sixteen lines, a dozen bullet points typed above the corporate logo of Morton Thiokol Inc. At the bottom was a simple, unequivocal statement of the kind the director of the Marshall Space Flight Center preferred: MTI RECOMMENDS STS-51-L LAUNCH PROCEED ON 28 JANUARY 1986.
Dr. Lucas, adhering to a strict interpretation of NASA’s pyramidal reporting structure, saw no need to share word of Thiokol’s initial qualms with his superiors. He had in his hand a signed launch recommendation; the matter was closed.
Over on the third floor of the Operations and Checkout Building, the seven Challenger astronauts gathered once again for a steak-and-eggs breakfast in the dining room of the crew quarters. In matching white polo shirts, for the second time they posed for prelaunch pictures around a table decorated with a centerpiece of red and white roses and a pair of small American flags, and a fresh cake frosted with the mission patch. Then, in a conference room down the hall, the crew received a final meteorology briefing from Houston: the cold weather was pushing the permissible limits for shuttle flights, so they could expect to wait for a while on the pad, but—for now, at least—the launch was still on. With a new time officially set for 10:38 a.m., they would likely lift off around noon. Back in their rooms, they changed into their flight overalls, packed up anything not destined for orbit into attaché cases and suit bags, and left it behind for NASA staff to return to Houston later in the day.
A little before 8:00 a.m., the astronauts rode the elevator downstairs, and walked out toward the waiting Astrovan. Led by Dick Scobee, they looked cheerful and excited, their faces washed by the orange light of the low morning sun. The last member of the crew in line was Greg Jarvis, and as he came down the ramp a small gang of his friends from Hughes cheered and clapped, waving a homemade banner: HAVE A GREAT FLIGHT GREGO, it said in big black-and-red capitals, beside a cartoon shuttle blasting skyward on a plume consuming the numbers of all mission assignments he’d been given so far: 51-D–51-I–61-C–51-L. Behind Jarvis came John Young and, beside him, wearing a suit and tie, George Abbey. As he stepped outside into the glare of the camera lights, the Director of Flight Operations shot an apprehensive glance at the sky.
Out on the pad, temperatures had reached their lowest shortly after dawn, falling to 24 degrees Fahrenheit—eight degrees below freezing. The seething cold had crept into everything: the doors on the gantry elevator had become sluggish; several of the remote cameras had stopped working; an oxygen sensor aboard the shuttle had failed; one radio channel had been knocked out; and, down on the Mobile Launcher Platform, beneath the nozzles of the solid rockets—and in defiance of the hundreds of gallons of antifreeze—water in the sound suppression troughs had frozen solid. Sheer cascades of ice now descended from near the very top of the launch tower, bearding the walkways just sixty feet from Challenger’s left wingtip and encapsulating communications equipment. “Looks like, uh, something out of Dr. Zhivago,” said the Rockwell liaison, surveying the closed-circuit TV images from the Launch Control Center; he had never seen anything like it. “There’s sheets of icicles hanging everywhere,” he said. Drowsy from lack of sleep, he sat back at his console and waited for the launch to be scrubbed.
In the meantime, Charlie Stevenson and his team had returned to the pad and begun smashing up the frozen water in the sound suppression troughs with long-handled nets and sweeping ice into the flame trench. As they took temperature readings around the shuttle with a handheld infrared thermometer, the instrument produced odd results: the surface of the left-hand solid rocket booster registered at around 25 degrees Fahrenheit, close to the air temperature at sunrise. But at the bottom of the right-hand booster, near the aft field joint, the reading was just 8 degrees—an astonishing 24 degrees below freezing; that just couldn’t be right. Stevenson and his engineers assumed the thermometer was malfunctioning, and took note of the numbers, but kept the data to themselves. Inside the Launch Control Center, the ice remained the major concern: Rockwell technicians at the Cape and in California continued to discuss the threat it posed to the shuttle over the internal communications net. Ahead of a final NASA mission management meeting, they had to use their own computer models to decide whether to give their go-ahead for launch—but it seemed impossible to predict what would happen if thousands of fragments of ice were sent ricocheting from the gantry when the shuttle engines lit. “It’s still a bit of Russian roulette,” the chief engineer at Downey said. “You’ll probably make it. Five out of six times you do, playing Russian roulette.”
Led by a white NASA security car topped with blue warning lights, it took the Astrovan a little more than twenty minutes to cover the nine miles to Pad 39B, stopping twice along the way: first to drop off John Young, who would make a final reconnaissance flight in the Shuttle Training Aircraft to check the weather over the Cape, and then George Abbey, who left at the Launch Control Center to join the other managers in Firing Room 3. The van sped northeast, straight up the deserted causeway toward the ocean, and made a sharp turn two miles from the pad, flashing through the deep shadows cast by the subtropical scrub. Then the driver turned into a long right-hand bend, and the seven astronauts saw their spacecraft revealed slowly before them, framed in the front windshield against a turquoise sky. Raised on a massive concrete ramp and anchored to the great, gray superstructure of the launch platform, Challenger lay dead ahead at the end of the road: fully fueled and ready to depart.
As the high-speed elevator carried them almost twenty stories up the launch tower, Commander Scobee and his crew could hear that their ship had come to life: the external tank heaved and groaned as its thin aluminum skin contracted in the cold, exhaling a stream of boiling liquid oxygen from beneath the conical “beanie cap” resting at its tip. When the doors slid open at their destination on Level 195, Scobee took a deep breath and smiled up at the sky; behind him, the Atlantic rollers glinted silently in the sunshine.
“This is a beautiful day to fly,” he said.
“It’s a little cold, though, Dick,” said Johnny Corlew, once again leading the closeout crew for the day.
“Nah, that’s good, that’s great,” Scobee said, shaking his head.
Even so, as they crossed the swing arm toward the White Room, the closeout technicians warned the crew about the treacherous slick of ice on the walkway. Judy Resnik shivered in her thin flight suit and, as he waited his turn to enter the orbiter, Mike Smith pulled out a folded white handkerchief from his top pocket to wipe his nose. But the mood was buoyant: as he entered the White Room to pull on his harness and helmet, Scobee beckoned to the chief Lockheed technician. “Here,” he said, “you guys might need this today. Hang on to it.”
It was a small alloy bolt, tied with a red ribbon.
The commander knelt to crawl into the orbiter, followed by Smith and Ellison Onizuka, who was teased by the technicians about his flight jacket, decorated with the patch of a previous shuttle mission. “Well,” the astronaut said, “at least we’re not on the Dan Rather show, like somebody I could name.”
Resnik would take the flight engineer’s position in the cockpit, behind the commander’s and pilot’s seats, and was the last of the upper-deck crew through the hatch. Before she crouched to cross the threshold, she turned to Christa McAuliffe. “The next time I see you, we’ll be in space,” she said.
Johnny Corlew had grown up in Indiana, and as a boy had picked apples for his teachers from the tree in his yard; this morning he had brought his own gift to the pad for McAuliffe: a Red Rome apple he’d had his wife pick up at the supermarket for the occasion. The Teacher in Space raised the fruit to her face with a smile, but then immediately returned it. “Save it for me,” she said. “And I’ll eat it when I get back.”
Greg Jarvis, grinning and chatting before the technicians helped him into the tight-fitting clamshell helmet, was next.
“Well, we’re really going to go today,” Corlew said.
“Yeah,” Jarvis replied. “I sure hope so.”
Finally, Ron McNair shrugged into his equipment. He shook hands with the White Room team, stooped onto all fours, and crawled over the step to take his seat on the middeck.
Inside, the astronaut attached to the closeout team, Sonny Carter, moved from one member of the crew to another, tightening their harnesses, completing headset communication checks, and adjusting cables and hoses. As he hunched over McAuliffe to inspect her helmet one last time, he looked down into her face and saw that her Girl Scout pluck had deserted her at last. In her eyes he saw neither excitement nor anticipation, but recognized only one emotion: terror.
A few moments later, Carter crawled from the orbiter and Johnny Corlew swung the hatch shut behind him. It closed with a bang, and the latches fell into place.
Back in the Launch Control Center, the ground controllers broke into a round of applause.
It was 9:07 a.m.
Dawn was approaching in Southern California when Rocco Petrone, President of Rockwell’s Space Transportation Division and a legendary former manager at NASA, picked up the phone to call his subordinates in the Firing Room on Merritt Island. A burly Italian American who had masterminded the construction of the facilities at Cape Canaveral and then overseen the Apollo program through the launchpad fire, the moon landing, and Apollo 13, Petrone ran the West Coast contractor’s shuttle operations with an iron hand—and had left the Cape in disgust the previous afternoon, after witnessing the bolt fiasco unfold on Pad 39B. Now, watching the closed-circuit TV images of the icicles festooning the gantry and equipment around Challenger from the plant in Downey, he told his managers to make it clear to NASA that Rockwell could not approve the launch. “It is not safe,” he said.
But the final decision now lay in the hands of the two most senior members of the Mission Management Team seated on the top tier of Firing Room 3: the chief of the shuttle program in Houston, Arnie Aldrich, and his boss, Associate Administrator for Space Flight Jesse Moore. Aldrich, forty-nine years old, was another NASA veteran, who had started with the agency as a flight controller for the Mercury program at the end of the 1950s, and had worked on the shuttle since the beginning; he was confident he knew as much as almost anyone at the agency about the foibles of America’s Space Transportation System.
Since taking the conference call in his hotel room at nearly midnight to talk to Larry Mulloy and Stan Reinartz about the recovery ships, Aldrich had managed to get little sleep: there had been another call at 3:00 a.m. to say that the count had slipped back by an hour, and that ice was building on the pad; at 4:30 a.m. he had arrived in the Firing Room to learn that the offshore winds had dropped, and the recovery ships would be in position to recover the spent boosters after all. But the ice on the pad could be a problem. Aldrich set the shuttle engineering teams at the Cape, and in Houston, Huntsville, and Downey, to analyze the risks and report back.
Soon after 9:00 a.m., the Launch Director put the countdown on hold, pushing liftoff back to no earlier than 11:08 a.m. In the meantime, Aldrich convened a meeting in the fourth-floor conference room of the Launch Control Center—attended by more than twenty senior managers and experts who had assessed the hazards of the freezing gantry. First, Aldrich heard the analysis from a team of NASA engineers: based on their calculations of wind speed, fragmentation, and debris trajectory, they felt good about the ice; it was unlikely to cause significant damage. They gave their go-ahead for launch, as soon as the air temperature rose above 31 degrees Fahrenheit. But when he turned to Rocco Petrone’s men, they passed on the message from their boss: the situation was unpredictable, and unlike anything they’d seen before, said one. The other was more direct. “Rockwell cannot assure that it is safe to fly,” he said.
And yet Aldrich had made up his mind: his own engineers were unanimous; a single dissenting voice—even from the contractors who had built the orbiter—was not enough to stop the launch. At around 10:00 a.m., he returned to the Firing Room, where he was immediately intercepted by George Abbey.
“What did you decide?” the Director of Flight Operations asked.
“We’re still a go,” Aldrich replied. He reminded Abbey that they were all on a tight schedule to get Challenger off the ground—and keep the rest of the year’s missions on track.
“Did Rockwell say they were a go?” Abbey asked.
But the countdown had already resumed.
Standing on the aluminum bleachers more than three miles from the launchpad, the crowd shivered in the cold, wrapped in winter coats, hats, and sweatshirts, and sipped hot coffee or cocoa to ward off the chill. Christa McAuliffe’s parents—Grace and Ed Corrigan—her sister, Lisa, and her brother, Christopher, were seated in the stands with other VIP guests, wearing buttons depicting Christa in her astronaut flight suit. Hundreds of other spectators had already left, chased away the previous day by the cold and the repeated delays: Ron McNair’s older brother and his pregnant wife had already made the long drive back home to Atlanta, along with his youngest brother, Eric, and their father. In the nearby Space Center campground, so often filled with whooping onlookers watching the launchpad from the roofs of their vans and Winnebagos, only a few stragglers remained. The crowd on the VIP bleachers was so thin that, earlier that morning, NASA had brought all of Scott McAuliffe’s third-grade classmates over by bus from the Banana River causeway to gather in their red, white, and blue baseball caps under a banner reading GO CHRISTA! At the request of photographers inside the media enclosure, the Corrigans had moved closer to the press—to bring them within range of their cameras at liftoff. “Christa would want to see what our faces look like,” her mother said.
Up on the fourth floor of the Launch Control Center, Steven McAuliffe and his children had gathered once more with the other astronauts’ families beneath the computer-printed banner in Gene Thomas’s office. There were more doughnuts from the nearby cafeteria, binoculars gathered on a table, and a videotape playing of the prelaunch coverage from earlier in the morning, including the crew breakfast and walkout. A separate TV set also continued to display live pictures from the pad, and the sheets of ice hanging from the gantry. Joy and Reggie McNair, once again in their miniature NASA jumpsuits, sat together on the floor: Joy played with Caroline McAuliffe, while Reggie pretended to fly a plastic Space Shuttle around the room. Alison Smith and her brother, Scott, took more naps on the chairs, and on the floor.
As the countdown entered yet another hold—while the NASA managers waited for the temperature to rise and the sun to melt some of the ice on the gantry—the adults sat quietly or stood around chatting. Jane Smith, still expecting the launch to be scrubbed at any minute, used the phone on a secretary’s desk to rebook her children’s plane tickets back to Houston. Lorna Onizuka, wearing a gray Mickey Mouse sweatshirt, drank coffee and cracked jokes; but her one-liners couldn’t entirely smother an undercurrent of anxiety.
Back in New Hampshire, seniors at McAuliffe’s high school in Concord had again packed the main auditorium, holding banners, balloons, and noisemakers, joining thousands of other students in schools across the country to witness the launch live on the feed from NASA TV. “All of America is watching and waiting,” CNN’s space correspondent Tom Mintier reported in a morning news update.
In Washington, DC, President Reagan was at the outset of a busy day in the White House: at 1:00 p.m. he was scheduled to meet a dozen national TV correspondents to give them a preview of the televised State of the Union address he would be delivering at nine that night. The speech had been the subject of intense last-minute wrangling among White House staff, tussling over how much tangible policy it should include, but NASA communications chiefs had suggested that Reagan mention the space program; the Teacher Flight seemed a perfect crowd-pleasing cue for the occasion. While the President met members of Congress in the Cabinet Room, the First Lady was upstairs in the Executive Residence, planning to watch the Challenger launch on television as it happened.
At 10:30 a.m., Launch Director Gene Thomas watched on the remote cameras as Charlie Stevenson and his team drove back out to Pad 39B in their white government van. The countdown clocks inside the Launch Control Center were holding, as scheduled, at T-minus 20 minutes. High up in the cockpit of the orbiter, the Challenger crew bantered with one another over the intercom headsets, unheard by the public. They were still anticipating a scrub: “I hope we don’t drive this down to the bitter end again today,” Judy Resnik said.
Harnessed on their backs in the unyielding aluminum seats, the crew had little to do but wait for news from launch control: on the flight deck, Resnik, Onizuka, Smith, and Scobee were washed in sunlight and had a view to their left of the launch gantry and, above them, a cloudless cobalt sky. They attended to a handful of instrument checks and pressure readings and joked back and forth—about the cold, their breakfast, and the discomfort of yet more hours of supine inertia. But below on the middeck, Ron McNair, Greg Jarvis, and Christa McAuliffe saw only what sunshine struggled in through the porthole in the entry hatch and down the narrow flight deck gangway. Confined by their helmets and communications lines, the three astronauts had no tasks to perform during ascent, and would be scarcely more than cargo until they reached orbit. They would have almost nothing to look at beyond the wall of battered equipment lockers directly in front of them, and no source of information about their flight except their headset audio and the shuddering din from the solid rockets’ burn, as six million pounds of thrust rattled through every nut, bolt, and fixture inside the spacecraft. As the hours of waiting had wound on, Jarvis interjected in the cross talk from the cockpit. But both McNair and McAuliffe sat silently beneath the wan fluorescent light, alone with their thoughts.
One hundred feet below them on the deck of the launch platform, Stevenson and his men were using their nets to fish more ice from the green waters of the sound suppression troughs, and still sweeping frozen debris away from the shuttle. The Ice Team leader noted that on the sunny side of the gantry melting icicles were coming loose and tumbling to the steel deck below. But in the shadows, right where the wind came in off the ocean and supercooled air drifted up from the base of the external tank, Stevenson could see that the lower part of Challenger’s right-hand booster rocket was still freezing, glazed with a coating of ice an eighth of an inch thick that extended for thirty feet toward the strut holding it to the big orange fuel tank. Still, the air temperature had now risen above 34 degrees Fahrenheit: just within the formal limits NASA set for launch.
Inside Firing Room 3, the Director of Engineering was already making his final round of checks with the controllers at their rows of consoles.
“Any problems?”
“No problems.”
“We’re in good shape.”
“Y’all are go.”
“All our systems are go.”
But he was still awaiting word from the Ice Team; at last, Charlie Stevenson came in over Channel 245.
“The vehicle looks good,” he said.
In the cockpit, Dick Scobee heard the voice of launch control in his ear: the countdown was about to resume.
“Al-right!” the commander replied. “That’s great.”
In the windowless vault of Building 30 in Houston, Flight Director Jay Greene was making everything ready to assume control of Challenger on its path to orbit. Seated in the center of the hushed Flight Control Room, Greene was flanked by the eleven other managers and technicians who would monitor the launch, including the Flight Dynamics Officer—the FIDO—responsible for the spacecraft’s trajectory, and the day’s CapCom, astronaut and former Air Force pilot Dick Covey. Responsibility for Challenger would pass to them as soon as the shuttle cleared the tower at the Cape. Now Greene polled each member of his team in the ritual chant of affirmation that proceeded a confirmed launch:
“FIDO?”
“Go!”
“GNC?”
“Go!”
“INCO?”
“Go!”
“Surgeon?”
“Go!”
“CapCom?”
“Go!”
In the top tier of seats in the Firing Room, Jesse Moore conferred with Arnie Aldrich and Gene Thomas: the final decision about whether to launch would be his. The three men talked quietly for a few moments, and Moore looked over some paperwork. Then he nodded.
Terminal count.
Nine minutes.
It was 11:29 a.m.
On the fourth floor of the Launch Control Center, a NASA official began leading the wives and children out of Thomas’s office, down the hallway, past rows of cubicles, and out through a heavy self-closing door. One by one, they stepped out on to the roof and mounted the big steel staircase to the very top of the building: a broad expanse of pale concrete the size of a football field, surrounded by a white railing that cast a crisp shadow in the winter sunshine. Behind them, the black shapes of turkey vultures wheeled and soared in the thermals rising up the fifty-story cliff of the Vehicle Assembly Building. To the northeast, they had a perfect view: straight down the long path of the crawlerway toward the ocean and, to the left, of Pad 39B. They gathered at the rail; posed, smiling, for pictures.
From speakers on the roof, on the grandstands below, and all across Merritt Island, the voice of Cape Canaveral public affairs officer Hugh Harris picked up the count:
“The Ground Launch Sequencer has been initiated. T-minus 8 minutes, 30 seconds and counting. The flight instrument recorders are turned on.”
At the Morton Thiokol plant in Utah, the time was approaching 9:30 a.m. Some of the solid rocket team had gathered in the MIC room at the Wasatch plant to watch the launch, but neither Arnie Thompson nor Roger Boisjoly were among them. Instead, Thompson was in his office one floor below, going over the details of the previous night’s discussions with his colleagues. Boisjoly remained alone at his desk nearby.
But with only a few minutes of the countdown remaining, Boisjoly had left his office and was walking past the door of the conference room, when Bob Ebeling emerged to grab him by the arm, urging him to join the rest of the staff—and Ebeling’s two daughters—to watch the live feed from the Cape.
Boisjoly said no. “I don’t want to watch,” he said.
But Ebeling insisted.
Inside the MIC room, there were no seats left, so Boisjoly sat on the floor directly in front of the screen of the big projection TV, his back resting against Ebeling’s legs.
“T-minus 7 minutes, 30 seconds.”
Running thousands of diagnostic tests and checks each second, the Ground Launch Sequencer began the process of severing Challenger’s last connections to Earth. At the computers’ command, the crew access arm slowly retracted, swinging the White Room away from the orbiter hatchway with a robotic lurch. The solid rocket boosters were armed.
Four minutes.
Christa McAuliffe snapped down the visor of her helmet. She was breathing pure oxygen.
It was 11:35 a.m.
In the CNN studios in Atlanta, the producers switched over to broadcast live pictures from the Cape.
“T-minus two minutes and counting.”
The vehicle began running on internal power. The vent hood lifted from the top of the external tank.
On the flight deck, the banter continued.
“OK, there goes the LOX arm,” Smith said.
“Doesn’t it go the other way?” Onizuka said, and laughed.
“God, I hope not, Ellison.”
Ninety seconds.
In Firing Room 3, the console operators hunched over their screens. From his seat, Thiokol’s Allan McDonald kept one eye on the monitor displaying the chamber pressures of the solid rockets, and the other on a TV screen showing the shuttle. Behind him, the senior NASA managers—Moore, Aldrich, Lucas, Abbey—turned to gaze out through the massive wall of glass toward the pad. Larry Mulloy was standing, his headset on.
In the cockpit, Scobee and Smith watched as the automatic sequencer worked through the final moments before launch: the propellant systems came up to pressure; all three engines were ready to fire.
“Thirty seconds down there,” Scobee said.
“We are go for auto-sequence start.”
The crew heard the distant whirring as the onboard computers verified the responses of the shuttle hydraulics.
“Fifteen,” the commander said. Amber numbers blinked the final seconds of the countdown on the instrument panel.
Over the Kennedy Space Center loudspeaker system, the voice of Hugh Harris echoed the incantation for everyone to hear. The children in the grandstands joined in.
“T-minus ten.”
“Nine.”
“Eight.”
“Seven.”
“Six.”
Inside the shuttle, the whine of the turbopumps rose to a roar. One by one, the three engines lit.
“We have main engine start.”
At his console, Al McDonald broke into a cold sweat.
In Utah, Bob Ebeling and Roger Boisjoly held hands.
“Four.”
“Three at a hundred,” Scobee said; the trio of main engines had reached 100 percent thrust. The shuttle leaned away from the tower, straining against the hold-down bolts anchoring it to the Earth.
“Three.”
“Two.”
“One—”
The twin boosters lit: igniters simultaneously fired tongues of flame 150 feet long down the full length of the rockets’ hollow cores, and more than seven hundred tons of aluminum perchlorate exploded into life. Within six hundred milliseconds the pressure inside their steel casings rose to nearly one thousand pounds per square inch. Almost invisibly, expanding gases pushed the walls of the half-inch steel casings outward, each of the six field joints flexed open, and the O-rings encircling them began to move into the widening gaps between the rocket segments.
The hold-down bolts blew. Sheets of ice more than three feet across tumbled from the launch gantry.
“—and lift off, lift off of the twenty-fifth Space Shuttle mission, and it has cleared the tower.”
In the Thiokol conference room, Boisjoly looked up at Ebeling in relief. The seals had made it through ignition.
“We just dodged a bullet,” he whispered.
In the grandstands, Ed and Grace Corrigan stood side by side and watched their daughter ascend toward orbit, their faces lit with anxious smiles. They turned and embraced, linking hands with their daughter, Lisa. Standing on the roof of a small building nearby, Barbara Morgan, McAuliffe’s backup, hollered and clapped: “Whooo! C’mon, go!” she shouted, and gave a gleeful wave toward the departing spacecraft. “Bye, Christa! Bye, crew!” Above her on the Launch Control Center roof, Judy Resnik’s father, Marvin, stared intently skyward. Nearby, the three Smith children stood with their mother, witnessing their father’s patience rewarded at last; Alison gazed up and lifted the viewfinder of her Kodak camera to her eye. At Concord High School, the students let loose with whoops and cheers.
But in the bottom-most field joint of the right-hand booster rocket, the cold had done its work: the synthetic rubber of the seals and the thick grease they were packed in had proved too inflexible to close the gap that opened in the case at ignition. Hot gas at more than 5,000 degrees Fahrenheit had blasted past the primary seal—and then broken through the second seal, too, instantly vaporizing portions of the O-rings as it went. Unseen by the crowd or the officials in the Launch Control Center, burning grease, insulation, and Viton rubber spurted from the ruptured joint in puffs of coal-black smoke.
Seven seconds into the flight, the shuttle’s computers began to turn the orbiter onto its back as it thundered out over the Atlantic. Scobee opened his radio link with Mission Control.
“Houston, Challenger: roll program,” he said.
“Go, you mother!” said Smith. The shuttle rattled and shook like a runaway train as it accelerated toward the speed of sound, making it hard for the pilot to read the instruments.
From her seat behind them, monitoring the laminated ascent checklist open on her knee, Judy Resnik gave an exuberant yell: “Shit hot!”
“Oooo-kay!” Scobee replied.
Now the same forces of combustion that had destroyed the booster seal momentarily conspired to heal it. Within twelve seconds of launch, molten aluminum oxides from the burning propellant built up in the fissure in the aft field joint of the rocket, sealing the breach around the ruptured O-rings and cutting off the leak.
In Houston, public affairs officer Steve Nesbitt had taken over the public commentary, and was watching the streams of black-and-white numbers appearing on his monitors, waiting to explain the next major event in the flight to the millions watching on TV. To his left, Jay Greene swept his gaze over the engine performance data appearing on his console. Everything looked good.
The next part of the ascent program would reduce the thrust of Challenger’s three main engines to take the shuttle through Max Q: the phase of maximum dynamic pressure at which the aerodynamic forces acting on the spacecraft would reach their most extreme. To reduce stress on the airframe as the shuttle shot through the atmosphere at Mach 1, the engines would throttle back to 65 percent of their rated power for fifteen seconds, before returning to full thrust on the other side of the pressure wave.
The Flight Dynamics Officer made the call:
“Throttle down… three at sixty-five.”
“Sixty-five, FIDO,” Greene replied.
On the broad projection screen at the front of the Flight Control Room, the red line marking the shuttle’s trajectory tracked tightly to its nominal path. A perfect ascent.
Fifty-seven seconds into the flight, the maneuver was complete. In the cockpit, Scobee watched the thrust readings start to rise as Challenger’s computers began once more to increase engine power.
“Throttling up,” he said.
But as Challenger shuddered through Max Q, it was also buffeted by the worst high-altitude wind shear yet encountered on a shuttle flight. The entire shuttle stack flexed and twisted in the turbulence, shattering the delicate glassy residues that had resealed the hemorrhaged rocket motor. At fifty-eight seconds, an orange flame flared through the field joint at the bottom of the right booster.
Still clearly visible to the spectators on the ground at the Cape, the shuttle was approaching an altitude of 35,000 feet, and a velocity of one and a half times the speed of sound, its engines firing at 104 percent of rated power.
“Feel that mother go!” said Smith. “Wooohooo!”
The flame grew in intensity, deflected down in the slipstream of the rising spacecraft until it made contact with the external fuel tank, close to one of the three steel struts securing the bottom of the booster to the spine of the shuttle stack. Yet neither the instruments on Challenger’s flight deck nor the readings on the consoles in Houston gave any indication that anything was wrong. The onboard computers, struggling to keep the orbiter flying true, swiveled the nozzle of the left-hand booster outward to compensate for the loss of pressure in its malfunctioning twin.
“Challenger, go at throttle up,” the CapCom radioed from Mission Control.
“Roger, go at throttle up,” said Scobee.
Burning at more than 6,000 degrees, in less than three seconds the errant flame escaping from the booster encircled the circumference of the giant external tank, incinerated its insulation, cut through its aluminum skin, and ruptured the welds of the pressurized fuel tank membrane within. A plume of liquid hydrogen burst into the slipstream of the rocket engines, where it ignited.
In Atlanta, CNN space correspondent Tom Mintier, watching the pictures of the spacecraft flying away into the empty sky, began to wrap up his live commentary. “So the twenty-fifth Space Shuttle mission is now on the way, after more delays than NASA cares to count. This morning it looked as though they were not going to be able to get off—”
He stopped abruptly.
At seventy-two seconds, the tank lost its structural integrity and tore apart, crumpling and disgorging the remaining liquid hydrogen—more than 300,000 gallons of it—which bloomed into a colossal fireball. Released from its aft anchors, the right-hand booster swiveled around its upper attachment point. Its nose smashed into the right wing of Challenger, and the liquid oxygen tank, tearing it open.
The orbiter was engulfed in a swelling cloud of combustible propellant, and the nozzles of its three main engines swiveled wildly as the onboard computers struggled to regain control of the disintegrating spacecraft; for the few fractions of a second it took for the engines to consume the fuel remaining in the feed lines, their high-pressure turbopumps continued to spin, until the computers shut them down one at a time. Then the booster rockets tore free from their mounts, and Challenger, still hurtling toward space at almost 1,500 miles per hour, tumbled from its precisely prescribed supersonic trajectory. Its airframe stressed far beyond its design limits, the most complicated machine in history began to come apart in flight: its stubby wings ripped away, the cargo bay bursting like a paper bag, the inrushing air pulling the fuselage asunder from the inside.
At seventy-three seconds, the transmission of telemetry from the shuttle suddenly ceased. On Jay Greene’s console in Houston, on all the screens in Mission Control, the rapidly flickering lines of streaming data froze, and one column after another filled with the letter S.
Static.