Read Test Pilot's Daughter II: Dead Reckoning Online
Authors: Steve Ward
Seven-million pounds of thrust accelerate the orbiter to escape velocity, that’s Mach 26 or twenty-six times the speed of sound. When Chuck Yeager first broke the sound barrier at 767 mph in a tiny rocket-plane, it was a dramatic achievement, but just a baby step toward space travel. The experimental rockets flown in his later years went up to Mach 3 climbing to twenty miles, just high enough to see the curvature of the earth. But going to the Moon or achieving orbits of 200 to 300 miles is another thing altogether.
When space travel was first envisioned, back in days of Buck Rogers and Flash Gordon, Hollywood pictured a spaceship with reverse thrusters. Simply point the thrusters in the opposite direction and gently ease the spaceship back onto its launching pad. For the New Hope to land that way, its massive rockets would have to be more than twice the size.
Back in the ‘60s, when the moon launch was first considered, ingenious designers came up with a solution. The energy used for ascent would be dissipated on the return by sacrificing a portion of the spacecraft itself, a “reentry shield.” Where large meteors completely vaporize in the atmosphere, a material had to be found capable of only partially vaporizing on descent. The atmosphere would put on the breaks and slow the astronauts to a point where parachutes could be deployed. Both Mercury and Apollo programs proved the concept by designing reentry capsules which could maintain stability while partially burning off the outer layers of one surface with atmospheric friction.
The material chosen for those early ablation shields was fiberglass bonded with a phenolic resin. Ablative protection functioned by lifting hot gases away from the outer wall. Ablation caused the material to char, melt, and vaporize, blocking convective and catalytic heat flux from the vehicle and protecting the astronauts.
The problem with ablation shields is, they can only be used once. The thermal protection system for New Hope is much more sophisticated. Two decades of research and engineering resulted in wondrous new materials. Over twenty-thousand reusable tiles made of reinforced carbon-carbon and coated silica ceramics protect the interior of the spacecraft from the 2,300 degree heat of reentry.
Tiles,
Christina thought,
tiles.
As she worried about the violent jolt they experienced from debris, she contemplated the importance of those tiles.
Are they damaged?
she wondered.
We’ll soon find out.
Her mind wandered into the mathematics of thermo-dynamics and energy transfer when a familiar voice brought her back to the conscious world.
“Commander? Commander. . .do you read me?
Over!”
Michael almost shouted.
She shook her head to clear the cobwebs and said, “Uh. . .oh yeah, sorry Michael, loud and clear, over. How me?”
“What ya doin’ in there, takin’ a nap?”
“No, no, just reviewing reentry procedures. What do you see?”
“Okay, I’m underneath, maneuvering. Port wing. . .bottom and leading edge look clean.” There was a long pause, and then he came back, “Starboard, clean also. Not a scratch.”
“Great news, Michael, how ‘bout the belly?” she asked.
“Standby.” Another pregnant pause had the whole crew holding its collective breath. “Uh, wait one. . .we got somethin’ up front, just behind the nose. Holy shit!”
“What is it, Michael?” she gasped.
“There’s a gouge almost a meter long. . .at least two tiles completely missing. Looks like that debris did a job on us. Can’t believe it didn’t penetrate the skin.”
“Copy that, two tiles missing.” Her stomach leapt into her throat, but she tried to sound calm. The ill-fated shuttle, Columbia, flew through her brain.
As good as a death sentence, missing tiles.
She took a deep breath and relayed the message to Udahl.
He responded calmly, “Commander we need more details, can you get us some video?”
Michael turned on his camera and said, “Okay, here you go, take a look for yourself.”
“Michael, can we fix it?” Christina asked with crossed fingers.
“Uh. . .not sure. . .looks pretty bad. Guess we’re going to get a chance at that repair kit.” He cleared his throat and shifted tone, “Why sure, Commander, no problem. We can fix it right up. I’ll swing around the bird and look for any more damage, then I’ll be headin’ in.”
“Roger, please be careful.”
It took almost an hour for him to wrap up the inspection. Udahl had him stick his gloved fingers in the damaged areas to try and estimate the size of the voids.
Christina asked Udahl about their options and learned the bad news. Any chance of rescue exceeded the envelope provided by their limited supply of fuel and oxygen. Because of all the maneuvering to attack ICBMs, they didn’t have enough fuel to make it to the space station. And, of course, Russian transports were out of the question. The U.S. was down to its last shuttle.
Looks like we’re on our own.
She sucked in a big breath and steeled her grit.
There was only one tiny glimmer for New Hope: a long considered, but never tested, rework of tiles in orbit. She and her two crew members frantically went through the procedures as they waited on Michael’s return. Ever since the Columbia disaster in 2003, NASA engineers had provided a kit, capable of replacing a few tiles by stacking in small, carbon bricks. It also included adhesives that could fill large cracks. Of course, no one knew if such a repair would survive the extreme heat and vibration of reentry, but it was their only option.
The problems of nuclear war faded away as Christina fought her own war against the hazards of space. They had a chance, but it was a slim one. That afternoon all four astronauts suited up and spent six hours underneath the giant spaceship working on repairs.
“Make ‘em pretty now,” she said. It was a sad attempt at humor. “Just think, we can always get a job at a body-shop.”
“How about a used car dealer?” Michael chuckled.
All highly motivated, no one complained about the long, sweaty task. It was a simple choice: either fix the tiles or die.
* * *
For the second time in 48 hours, it was “come to Jesus” time for Christina Matthews. They had done their very best to repair the shield, and the re-entry procedure was just minutes away. Although the two military specialists were somewhat clueless, Christina and Michael knew what they were up against. Before they put on their helmets, he put his hand to her face and looked at her with sad eyes.
“Christina, before we hit the brakes, I just want you to know how much I. . .”
“You don’t have to say it, I will. . .I love you too.”
“Well, just in case something goes. . .”
“Don’t say it. . .it’s bad luck. Nothing is going to go wrong. Do you hear me?”
“But. . .”
“Shut up, Michael. We’re gonna make it. I know we are. Now put on your helmet, and let’s get busy.”
Even with the protection of undamaged tiles, reentry was a violent proposition. If the patchwork bricks gave way under the enormous pressure of reentry plasma, they were toast. Just as they crossed over the western border of China and hurtled out over the Pacific Ocean, Christina made the call.
“Mission Control, this is New Hope. All buckled down here and setting up for reentry.”
“Roger,” Udahl replied with his usual tone of tranquility. “The boys down here like your quilting job, Commander. Don’t worry, the engineers say it’ll work.”
“That’s comforting,” she replied, “but they don’t have to ride this rattle-trap.”
In its standard, inverted attitude, nose forward, the reverse thrusters necessary for shuttle reentry were pointing in the wrong direction. The first procedure was to flip the spaceship over for the burn, then back for reentry.
“Flipper burn on my mark. . .three, two, one, mark.” She fired the tiny thrusters to pitch the aft end of the ship all the way over the top. She watched her situation display and aligned the crosshairs. “Ass forward and on the mark. Look ma, we’re flying backwards,” she joked, trying not to sound the way she really felt,
scared shitless!
“Roger, Commander. T-minus-five minutes to reentry burn.”
“Standing by. . .ready for burn.”
“T-minus-one minute. . .five, four, three, two one,
burn!”
She flipped the switch to fire the rockets and felt a jolt. In order to reenter the earth’s atmosphere, all they had to do was cut 1% off the spaceship’s momentum. “A-okay, ground, a perfect twenty-two second burn. We’re headin’ home.”
As the shuttle sped backwards at 17,740 mph, trimming the velocity by only 200 mph dropped them out of orbit.
“Commander, looks good on this end. You can roll her back for reentry, and God’s speed.”
“Rolling 180. Yaw thrusters active. Yippee, comin’ around like a carnival ride. Aaah,” Christina sighed. “I like this attitude much better; feels more like a real airplane. We’re on line and pitching forward. Locked on nominal descent angle.”
Achieving a shuttle descent angle of exactly 40 degrees was critical. Any less and the shuttle would fly long without hope of landing at Cape Canaveral. Any more than 40 degrees and they would be reduced to ashes.
Michael made his report from the co-pilot seat, “All systems green, clock rolling, six-niner minutes to touchdown. Hey Udahl, would y’all please put on the coffee?” he chuckled.
“Regular or decaf?”
As New Hope entered the thin, upper layers of atmosphere, a pressure wave began to develop on its leading edges. A superheated shroud of incandescent plasma formed as the air molecules ripped apart, and their component atoms ionized. Plasma, sometimes called the fourth state of matter, began to envelop the shuttle in a brilliant corona known as St. Elmo’s fire. It was always something to watch. Unfortunately, this time it was more than a glow. Christina was sure she could see chips breaking off the shield like a Roman candle on the 4
th
of July.
“Losin’ material,” she reported. “C’mon baby, hold together a few more minutes.”
There was a high frequency vibration which she hadn’t felt before, and sweat beaded on her brow. She knew it was at this point that a hole in the leading edge of Columbia’s left wing began to glow with disastrous results. Plasma heating burned a concave section into Columbia’s wing, increased the drag and turned the doomed shuttle sideways. It was just a matter of seconds before the entire structure came apart like a hundred meteors cast down on east Texas. Those unfortunate astronauts didn’t feel a thing.
Ashes to ashes, dust to dust,
Christina thought. She monitored her attitude as the vibration increased, and the ionization cloud glowed outside her window. She tried not to think what the hot plasma was doing to their patchwork.
So far so good,
she thought.
It was a long twenty minutes, and the vibrations were intense, but they were still in one piece.
“Range 2,000 miles, altitude 50. A lot of shaking now, getting some aerodynamic control. Computer banking for the first braking-turn. Twenty minutes to touchdown, plasma very bright now, and we g-o-o-ot the sha-a-akes.” She knew they could hear her voice cracking, because it rang out clearly through her own headset. She sounded like a truck driver’s CB voice on a rough road. “Breaker 19, breaker 19, get those cameras ready, we’re comin’ in. See any smokies down there? Come back.” She envisioned the control room at JSC and knew all the ground personnel were crossing fingers, gnawing cigars, and holding their breaths.
“Relax, Commander. . .made in the shade,” Udahl hummed.
“Easy for
you
to say. This is some galloping po-o-ony.” She looked toward Michael, but he was a blur. Unlike early space capsules, New Hope never lost communications on descent, and both cockpit voice and telemetry were monitored all the way down by Mission Control.
“Commander, snap to; you need to check your situation display. You’re some five degrees off course, error growing.”
She had her hands full. A few minutes later she transmitted in a shrill voice, “We’re hypersonic, Mach 8, rapidly decelerating, twenty miles altitude, and this baby’s trying to slip away from the computer. Skin temp 2000C, that’s 300 over nominal. Seven minutes out. Standby one, gonna have to override, we’re losin’ it. Okay, I got the controls, maneuvering at Mach 4 and pitching forward into our last braking turn. Give me a second. . .coming around, okay, got her back on trajectory, controls responding, but they’re sluggish,” she complained. “Michael, you need to help me with this, can’t seem to get enough backpressure on the stick.”
“I’m with ya, honey, hang in there,” an obvious breach of protocol.