Gravity. Tess Gerritsen
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touchdown at Kennedy. A single mistake would send Endeavour plunging into the sea.
Their lives were now in the hands of Commander Kittredge.
His voice, in constant communication with Mission Control, still sounded steady, even a little bored, as they approached the two-minute mark. The next crisis point. The CRT display flashed the Pc<50 signal. The solid rocket boosters were burning out, on schedule.
Emma felt it at once, the startling deceleration as the boosters consumed the last of the fuel. Then a brilliant flash of light in the window made her squint as the SRBs exploded away from the tank.
The roar of launch fell ominously silent, the violent shudder calming to a smooth, almost tranquil ride. In the abrupt calm, she was aware of her own pulse accelerating, her heart thudding like a fist against her chest restraint.
‘Control, this is Endeavour,’ said Kittredge, still unnaturally calm. ‘We have SRB sep.’
‘Roger, we see it.’
‘Initiating abort.’ Kittredge depressed the Abort push button, the rotary switch already positioned at the RTLS option.
Over her comm unit, Emma heard Jill Hewitt call out, ‘Emma, let’s hear the checklist!’
‘I’ve got it.’ Emma began to read aloud, and the sound of her own voice was as startlingly calm as Kittredge’s and Hewitt’s. Anyone listening to their dialogue would never have guessed they faced catastrophe. They had assumed machine mode, their panic suppressed, every action guided by rote memory and training. Their onboard computers would automatically set their return course. They were continuing downrange, still climbing to four hundred thousand feet as they dissipated fuel.
Now she felt the dizzying spin as the orbiter began its pitch-around maneuver, rolling tail over nose. The horizon, which had been upside down, suddenly righted itself as they turned back toward Kennedy, almost four hundred miles away.
‘Endeavour, this is Control. Go for main engine cutoff.’
‘Roger,’ responded Kittredge. ‘MECO now.’
On the instrument panel, the three engine status indicators suddenly flashed red. He had shut off the main engines, and in twenty seconds, the external fuel tank would drop away into the sea.
Altitude dropping fast, thought Emma. But we’re headed for home.
She gave a start. A warning buzzed, and new panel lights flashed on the console.
‘Control, we’ve lost computer number three!’ cried Hewitt. ‘We have lost a nav-state vector! Repeat, we’ve lost a nav-state vector!’
‘It could be an inertial-measurement malf,’ said Andy Mercer, the other mission specialist seated beside Emma. ‘Take it off-line.’
‘No! It might be a broken data bus!’ cut in Emma. ‘I say we engage the backup.’
‘Agreed,’ snapped Kittredge.
‘Going to backup,’ said Hewitt. She switched to computer number five.
The vector reappeared. Everyone heaved a sigh of relief.
The burst of explosive charges signaled the separation of the empty fuel tank. They couldn’t see it fall away into the sea, but they knew another crisis point had just passed. The orbiter was flying free now, a fat and awkward bird gliding homeward.
Hewitt barked, ‘Shit! We’ve lost an APU!’
Emma’s chin jerked up as a new buzzer sounded. An auxiliary power unit was out. Then another alarm screamed, and her gaze flew in panic to the consoles. A multitude of amber warning lights were flashing. On the video screens, all the data had vanished. Instead there were only ominous black and white stripes. A catastrophic computer failure. They were flying without navigation data. Without flap control.
‘Andy and I are on the APU malf!’ yelled Emma.
‘Reengage backup!’
Hewitt flicked the switch and cursed. ‘I’m getting no joy, guys. Nothing’s happening—’
‘Do it again!’
‘Still not reengaging.’
‘She’s banking!’ cried Emma, and felt her stomach lurch sideways.
Kittredge wrestled with the joystick, but they had already rolled too far starboard. The horizon reeled to vertical and flipped upside down. Emma’s stomach lurched again as they spun right side up. The next rotation came faster, the horizon twisting in a sickening whirl of sky and sea and sky.
A death spiral.
She heard Hewitt groan, heard Kittredge say, with flat resignation, ‘I’ve lost her.’
Then the fatal spin accelerated, plunging to an abrupt and shocking end.
There was only silence.
An amused voice said over their comm units, ‘Sorry, guys. You didn’t make it that time.’
Emma yanked off her headset. ‘That wasn’t fair, Hazel!’
Jill Hewitt chimed in with a protesting, ‘Hey, you meant to kill us. There was no way to save it.’
Emma was the first crew member to scramble out of the shuttle flight simulator. With the others right behind her, she marched into the windowless control room, where their three instructors sat at the row of consoles.
Team Leader Hazel Barra, wearing a mischievous smile, swiveled around to face Commander Kittredge’s irate crew of four. Though Hazel looked like a buxom earth mother with her gloriously frizzy brown hair, she was, in truth, a ruthless gameplayer who ran her flight crews through the most difficult of simulations and seemed to count it as a victory whenever the crew failed to survive. Hazel was well aware of the fact that every launch could end in disaster, and she wanted her astronauts equipped with the skills to survive. Losing one of her teams was a nightmare she hoped never to face.
‘That sim really was below the belt, Hazel,’ complained Kittredge.
‘Hey, you guys keep surviving. We have to knock down your cockiness a notch.’
‘Come on,’ said Andy. ‘Two engines down on liftoff? A broken data bus? An APU out? And then you throw in a failed number five computer? How many malfs and nits is that? It’s not realistic.’
Patrick, one of the other instructors, swiveled around with a grin. ‘You guys didn’t even notice the other stuff we did.’
‘What else was there?’
‘I threw in a nit on your oxygen tank sensor. None of you saw the change in the pressure gauge, did you?’
Kittredge gave a laugh. ‘When did we have time? We were juggling a dozen other malfunctions.’
Hazel raised a stout arm in a call for a truce. ‘Okay, guys. Maybe we did overdo it. Frankly, we were surprised you got as far as you did with the RTLS abort. We wanted to throw in another wrench, to make it more interesting.’
‘You threw in the whole damn toolbox,’ snorted Hewitt.
‘The truth is,’ said Patrick, ‘you guys are a little cocky.’
‘The word is confident,’ said Emma.
‘Which is good,’ Hazel admitted. ‘It’s good to be confident. You showed great teamwork at the integrated sim last week. Even Gordon Obie said he was impressed.’
‘The Sphinx said that?’ Kittredge’s eyebrow lifted in surprise. Gordon Obie was the director of Flight Crew Operations, a man so bafflingly silent and aloof that no one at JSC really knew him. He would sit through entire mission management meetings without uttering a single word, yet no one doubted he was mentally recording every detail. Among the astronauts, Obie was viewed with both awe and more than a little fear. With his power over final flight assignments,