Authors: Stephen Baxter
Not that it was recognized as such, by NASA.
Maybe today would be a kind of vindication, Deeke thought.
And now, the moment was approaching.
“Everything looks good here.”
“Manifold and lines looking good. Launch light going on.”
Still no cancellation.
“And we’ll call that three, two, one, launch—”
“Three minutes. Orbiter main engines gimballed to launch positions. T minus two fifty-five. External Tank oxygen vents closed. Pressurization of the tank has started. You’re configured for lift-off. Two minutes. Set APU to inhibit.”
Libet turned a switch. “APU auto shutdown to inhibit.”
“Sound suppression power bus armed.”
Angel said, “Visors down.”
“Launch crew calls Godspeed,
Endeavour.
”
“Thank you for that, Marcus.”
Benacerraf pulled closed her big faceplate. It clicked shut, and the whir of the cabin’s pumps and fans was muffled.
“
Endeavour
, control. Thirty-five seconds. Software mode 101 loaded. Hydrogen tank at flight pressure. APUs have started in the Solid Rocket Boosters. Go for redundant set launch sequence start. Twenty-five seconds. Smooth sailing, guys.
Endeavour,
control. You are on your on-board computer. Software mode now 102.”
“Copy that.”
Now the GPCs, the redundant general purpose computers on board the orbiter, had taken control of the launch sequence. Only one more command, for main engine start, would be sent from the ground.
Bit by bit, Benacerraf thought,
Endeavour
was cutting her ties to Earth.
Angel read off the continuing prelaunch events from his displays. “Pyrotechnics armed. Sound suppression system activated.”
“Fifteen seconds,” Libet said.
“SRB pyro initiation controller in its voltage limits… We got a live SRB destruct system.”
“
Endeavour
, we have a go for main engine start.”
“Rog,” Angel said. “Time to kick those tires and light that fire. Eight seconds. Position vector loaded…”
The geographic location of the launch pad had been turned into positional data inside the orbiter’s computers.
Endeavour
had become aware of its location as an object in three-dimensional space, only temporarily and accidentally clinging to the surface of a planet.
Angel said, “Engine flares ignited. Five, tour. We have main engine start.”
There was a remote bang, a premonitory shudder.
“There they go, guys,” Angel shouted. “Three at a hundred.”
The orbiter cabin creaked. Benacerraf could feel the displacement of the twang, through all of two feet: the Shuttle stack, pinned to the pad by posts at the base of its SRBs, flexed forward as it accommodated the thrust of its main engines.
Angel and Libet spoke at once. “Main engine pressure above ninety percent, all three.” “Engine status lights all green.” “Two, one. SRB ignition.”
For a few seconds, Jackie could make out a shower of sparks, bursting from the nozzles of the orbiter’s three main engines. Now a mist of propellants—liquid hydrogen and oxygen—was injected into the sparks, and a bright clear white light erupted at the base of the orbiter, and white smoke squirted out to either side.
The SRBs ignited. The plume of yellow light from the solid rockets was bright—dazzling, like sunlight, liquid light. There was a brief flash, as pyrotechnics severed the hold-down bolts pinning the stack to the pad.
The stack lifted off the ground, startlingly quickly, trailing a column of white smoke which glowed orange within, as if on fire. The movement of the huge Shuttle stack seemed impossible, as if a piece of a cathedral had suddenly taken leave of the Earth.
At the moment of launch there was a kind of release among the press flacks gathered in the stand. As one they stood, and there was clapping, cheering.
Jackie lifted her face to the rocket light that, for a few moments at least, was banishing the gray of winter.
It was, she conceded, a shame the boys weren’t here to see this.
And then the noise came, not a single roar but a succession of coughs and barks and crackles, like the popping of some immense oil fire. The ground shook, a rattling she could feel through her feet, on the bleachers.
To Benacerraf it was a shove in the back. It wasn’t a sharp spike of thrust—the Shuttle was much too heavy for that—more like riding an elevator of immense power, suddenly hurling her upward, but an elevator that would keep on going until it burst, cartoon-style, through the roof.
The cabin shook violently, and the noise engulfed her. The cockpit was filled with yellow-white light, diffused from the rockets’ glare, eighty feet below her. She could see chunks of ice, breaking off the hull of the External Tank, clattering against the pilots’ windows.
The mood of quiet calm which had characterized the preflight prep was dissipated in an instant. She was riding a rocket, and it felt like it.
A new voice came on the loop.
“Endeavour
, Houston. Launch tower cleared. Eight seconds. All engines looking good.”
“Copy that, Marcus.” Angel’s voice sounded thin, and it trembled with the vibration.
Mission Control at Houston took control of the flight once the Shuttle stack cleared the launch tower. Marcus White, voluntarily brought out of retirement once more, was the capcom there today. It had been done as a PR stunt—a Moonwalker in Mission Control—by the NASA PAO, desperate to milk this last moment of attention for all it was worth. But to Benacerraf, immersed in noise and vibration, it felt comforting to have White’s gravelly tones on the other end of the line.
“Eleven seconds,” Angel said. “Initiating roll maneuver.”
The orbiter went through a hundred and twenty degree roll to the right and pitched over as it climbed, to ease the aerodynamic loads on the complex stack.
Thus, thirty seconds after launch, she was suspended upside down, and hanging from her straps. The ground was visible above the heads of the pilots, receding quickly. Like her first flight, Benacerraf was surprised by the violence and speed of the maneuver.
“Shit hot!” Libet shouted.
It was like being shot downward, out of a cannon; it felt as it the X-15 had just exploded off the hooks.
The violence of the moment was bracing, exhilarating, an intrusion of reality. My God, he thought. It’s real. We’re really doing this.
Immediately the plane began to roll to the right. X-15 always had a tendency to do that, because of flow effects around the B-52’s launch pylon. He worked the left aileron to compensate.
He was basically in free fall right now, falling away from the B-52.
He felt adrenaline pump crisply into his system. It was time. He pressed his launch switch.
There was an explosive noise, like a shout. The main combustion chamber had ignited.
The bird was hurled forward.
He was pressed back, hard, into his seat and headrest. Another memory he’d suppressed. And he started to develop tunnel vision, with blackness shrouding the periphery of his view. He tried to remember what kind of instrument panel scan pattern he used back then. So much he’d forgotten.
The engine noise built up into a banshee squeal.
He rolled his wings level and pulled his nose up to a ten-degree angle of attack. The acceleration swiveled around, from the eyeballs-in of the launch to eyeballs-down at pullup. He felt as if he was climbing straight up, or even going over onto his back, He knew he had to discount the sensations, and just watch his instruments.
The B-52—flying at Mach point eight—just fell away behind him, as if it wasn’t moving at all.
The rocket engine was putting out full thrust. Now, for the next eighty or ninety seconds, it was Deeke’s job to ride this bull, to keep X-15 on the track that had been programmed for it on the ground.
Soon he would be accelerating at multiple Gs, which meant adding ninety miles per hour every
second.
He’d forgotten how impressive an aircraft X-15 was.
“Should be coming up on alpha,” the ground said.
Seven seconds. Deeke turned three degrees to the right to correct his heading. He kept one eye on the cockpit clock. Nine seconds. Ten seconds. Timing was everything in an X-15 flight. He checked his angle of attack, angle of sideslip, roll attitude, rate of climb.
Fifteen seconds. The acceleration looked nominal, still under two G. He watched his pitch attitude vernier needle, which was starting to come off its peg. Here it came, at eighteen seconds, moving towards the null position. At twenty seconds the needle was centered and he eased off on his angle of attack, to maintain the planned twenty-five-degree climb angle.
“You should be on pitch attitude now,” the ground said.
“Rog. Track looks real good. I feel as it I’m back in the saddle again. I wish I could do a barrel roll.”
“Rog that,” the ground said anonymously.
Yeah. You aren’t here to enjoy this, Linebacker.
At fifty thousand feet he shot through a layer of gray, hazy cloud. He emerged into a blue, infinite sky. The sun was still low, and it cast shadows on the ocean of cloud beneath him, which obscured the Earth.
He looked ahead, half expecting to see the Shuttle’s vapor stack, ahead of him; but his tipped-up windows showed him nothing but sky.
The handover from the KSC Firing Room had been as smooth as Barbara Fahy could have asked for. She didn’t even have to say anything. The ascent, complex and dangerous as it was, was just a process, she reflected, something they had handled more than a hundred times before, unfolding now with the inevitability of the logic of a well-tested software program.
Only the brilliant rocket light on the projected display at the front of the room gave any hint of the violence of the events the FCR’s devices were monitoring.
Even so, Fahy found it difficult to breathe.
… Now a new voice sounded in her ear. It was the range safety officer. It seemed that some unknown aircraft had wandered into the exclusion zone around the ascent profile.
Benacerraf looked ahead, out of the window beyond Angel. A layer of cloud hurtled at the orbiter like a wall.
Endeavour
shot through in a second, and emerged under a deep blue, domelike sky.
Angel closed switches, configuring the attitude indicator before him.
“There’s Mach point nine,” Libet said. “Okay, Mach one. Going through nineteen thousand.”
Forty seconds, Benacerraf thought, to reach the speed of sound from a standing start.
“Forty-four seconds.”
“Houston,
Endeavour.
Max Q. Into the throttle bucket.”
Max Q was a moment of danger, Benacerraf knew, the moment at which the Shuttle stack’s gathering velocity, coupled with the still-high density of the air, exerted maximum aerodynamic pressure on the airframe. The main engines had briefly throttled down to relieve the pressure.
“Copy,” Marcus White called. “Fifty-seven seconds.
Endeavour
, Houston. You are go for throttle up.”
“Copy that. Throttle up.”
“Wow,” Libet said, “feel this mother go.”
“Sixty-two seconds,” White said.
“Thirty-five thousand,” Angel said. “Going through Mach one point five.”
“Here we go,” Libet said. “SRB pressure is dropping.”
Already the solid rocket boosters were burning out.
“One minute fifty,” White called up. “Twenty-one miles high, eighteen miles down range.”
“Houston,
Endeavour.
Pressures less than fifty psi.”
“Copy.”
“SRB burnout.”
As the solid boosters died, it felt to Benacerraf like a dip, as if the Shuttle was suddenly falling out of the sky, just for a second. But then the acceleration built up powerfully once more.
“Ready for SRB sep.”
“Roger.”
There was a bang and a bright flash, beyond the orbiter’s panoramic windows, as the boosters’ separation motors ignited. It was as if she flew through a fireball.
“Okay, Linebacker, we have you right on track, on the profile.”
“Rog.”
Thirty-one seconds. The rocket burn roared on. Deeke worked his way around checks of his engine instruments, hydraulic pressures, generators, APU temperatures, stabilizer positions, cross-checking his altitude and velocity and rate of climb.
Thirty-five seconds. He shifted in his seat slightly, trying to get more comfortable; the G was already above two and was climbing fast.
“Stand by for eighty-three thousand feet.”
“Rog, eighty-three thousand.” Now his altitude too was piling up rapidly.
“Do you still read us, Linebacker?”
“Affirm.”
“Coming up on a hundred and ten thousand.”
“Hundred and ten, affirm.”
“On the profile, on the heading. On the profile.”
A minute fifteen.
He was already above the bulk of the sensible atmosphere. Ahead and all around him, the sky started to turn from a pearl blue to a deeper, dark blue. His vision seemed to stretch to infinity, to the gently curving, blue-white horizon; there was very little dust or mist above him.
The G forces were reaching their peak now—constant thrust combined with reducing aircraft mass to drive the acceleration higher—he was almost up to four G. This wasn’t excessive, Deeke knew, but it hurt his aging chest; he felt he had to fight to take a breath.
“Stand by for shutdown.”
“Standing by.”
The airframe popped and banged, its skin panels buckling and cracking as he climbed through four G. He’d heard such noises before. The pilots used to call it the oil-can effect. Outside air would work its way into the aircraft through small gaps in external doors or panels; the air was like a torch at high speeds, and would burn electrical wiring, aluminum internal structure and metal tubing, and smoke would waft into the cockpit.
But the X-15, even after decades in a museum, was a tough old bird.
A minute twenty-three. Deeke closed the shutdown switch.
The roar of the engine tailed off into a high-pitched, hog-calling squeal, then ceased.
Suddenly he was weightless; he was thrown forward against his restraints, and he felt his stomach lurch within him.
He was gliding, at almost five Mach, a stone hurled from a catapult.