Riding Rockets (51 page)

Hoot was immediately on the microphone. “Houston, Mike is right. We’re seeing a lot of damage.”

But after a short delay the CAPCOM came back with the original ho-hum assessment of “It’s not a problem.”

We all looked at one another in disbelief. Are they blind? Did they think the white streaks were seagull shit? It was obvious to us that we had taken a very bad hit. Maybe the image that was arriving on the MCC monitors was of poorer quality than what we were seeing. I tried to sharpen the image but was no more successful than Hoot had been.

Hoot tried again to convey the seriousness of what we were seeing and, again, MCC casually dismissed his concerns. We were in the Twilight Zone.
Who is this speaking to us and what have you done with the real MCC?
Maybe, I thought, MCC did know we had suffered major damage and were hiding that fact from us. There was precedence for that. On John Glenn’s Mercury mission the MCC had an instrument indication that his heat shield had come loose from his capsule, but they kept the information from him. Since there was absolutely nothing he could do about a loose heat shield, and, if it was loose, he was going to die, they reasoned there was no reason to tell him the truth. Without giving him an explanation, they had instructed Glenn not to jettison his retrorocket pack in hopes its retention would help keep a loose heat shield in place. It turned out there had been nothing wrong with the heat-shield attachment and Glenn was angry with MCC for withholding information from him. Could MCC be hiding a deadly situation from us? I couldn’t believe that. The MCC never gave up. If they suspected we had a serious problem, they would be pulling out every stop to get us home. It would be
Apollo 13
all over again. Their dismissive attitude must mean they believed we were okay. But I was going to be really suspicious if tomorrow’s wake-up music was “Nearer, My God, to Thee” and there was a teleprinter message saying we didn’t have to eat our broccoli.

Hoot set the mic aside, obviously frustrated and angry. No matter what MCC was seeing on their TVs, he felt they weren’t seriously considering what
we
were seeing. At the moment I was glad our mission was classified. The public and press had not heard any of our discussion. Unless one of the family escorts told the wives of our problem they would not know about it. I prayed that was the case. There was nothing they could do and they didn’t need the extra anxiety.

I couldn’t sleep and floated upstairs to watch the sights. The autopilot was holding the shuttle’s belly to the Sun, courtesy of our tire leak, so I had to move from window to window to get the best view. I was annoyed at the inconvenience…until our unique attitude served up a space sight I had never seen before. I was looking through the overhead windows in a direction that was precisely “down”-Sun when the upward-pointing attitude control thrusters fired. As their effluent of billions of ice crystals blossomed above the orbiter, a perfect shadow of
Atlantis
appeared and was carried into infinity at hundreds of miles per hour. The strikingly beautiful sight reminded me of Captain Kirk’s
Starship Enterprise
dashing into warp speed. I kept staring, hoping the display would repeat but it did not. The Sun dipped below the horizon and
Atlantis
was plunged into preternatural darkness. But there was one certainty about orbit flight: the passing of one incredible space sight only meant the arrival of another. My eyes were drawn to the lime green curtain of an aurora borealis waving over the Arctic Ocean far to the north. It brightened and dimmed as the rain of magnetic particles from the Sun varied in intensity. I was still staring at this phenomenon when the long streak of a shooting star brought my mind back to our heat-shield problem. In just a few hours that would be
Atlantis
…a shooting star blazing across the Pacific with a tail of ionized gas a thousand miles long. We were locked in an aluminum machine that would melt at 1,000 degrees. On reentry the belly tiles would be subjected to 2,000 degrees. The nose and leading edge of the wings would see even hotter temperatures. Just a couple inches of silica and carbon fiber were all that protected us from immolation, and our camera survey had shown some of those inches had been ripped away. The heat would definitely be getting closer to that aluminum. And what about the missing tile? Could the wind use the cavity it created to grab the edge of adjacent tiles and strip even more off, just like roof shingles being sequentially stripped in a hurricane? Engineers had always assured us that was not possible, but then I was certain the SRB nose cone engineers would have assured us their work could not fail either.

Of one thing I was certain. If
Atlantis
’s wounds were mortal, our fortress cockpit would protect us long enough to watch death’s approach. Certainly it would last long enough for us to see multiple warning messages as various systems were affected by the heat. We would probably live to experience the out-of-control tumble and breakup of the vehicle. Even after our fortress was penetrated by the incandescent heat, death would not be immediate. Our pressure suits would protect us from the loss of cockpit air. Only when the fire penetrated the fabric of our LESes would we die. If we were lucky, unconsciousness would come before the heat began to consume our flesh.

I kept returning to MCC’s assessment for comfort. It was hard not to yield to their conclusion that we were going to be fine. I had never been associated with any teams as good as those that manned the MCC. But if
Challenger
had proven anything, it was that great teams do fail. A lot of very smart people had mishandled the O-ring issue that killed the
Challenger
crew. Were they now mishandling our heat-shield damage? Would an
Atlantis
presidential commission report end up containing the statement, “The crew radioed that the damage to their heat tiles looked serious, but in Houston their concerns were dismissed”?

The anxiety was exhausting and I finally gave in to Hoot’s solution. The day before, as he floated to the windows to do some sightseeing, he said, “No reason to die all tensed up.” I would do my best to relax and enjoy the sights.

Chapter 35

Riding a Meteor

“Fifty seconds.” Hoot gave the time remaining until the OMS deorbit burn. I floated behind Jerry Ross and watched the countdown on the computer displays. As the burn execute time neared, I tightened my grip on Jerry’s seat. The one-quarter G of the thrusting OMS engines was trivial but it was enough to put anything unrestrained on the back wall, me included.

Astronauts have great faith in the OMS engines. They are the essence of simplicity. They have no spinning turbo-pumps to worry us, not even an igniter to fail and jeopardize our lives. The fuel and oxidizer are pushed into the combustion chamber by helium pressure, and their chemical composition causes them to ignite on contact. No spark needed. Getting stuck in orbit would ruin your whole day, so having a deorbit engine that was as foolproof as possible eased one of our perennial worries.

At time-zero the cockpit shuddered under the hammer of the two engines. Small bits of food crumbs, which had escaped our cleanup, drifted to the back wall. Hoot and Guy watched the computer displays of helium pressures, temperatures, and other indications of engine performance. They were all nominal.

The burn, and its acceleration on our bodies, ended. We were back in weightlessness. Hoot checked the residuals, which indicated the error of the maneuver. They were negligible. Whatever fate awaited us, we were now irrevocably committed. The OMS deorbit burn had clipped 200 miles per hour from our speed and changed our orbit so its low point was into the Earth’s atmosphere. There was no way we could climb back up to the temporary sanctuary of orbit.

According to the checklist I should have been strapped into the mid-deck seat, but there was nothing to do or see down there, so I had asked Hoot if I could hang out on the flight deck and shoot some video of the early part of reentry. I would get into my seat before the Gs got too high.

During the next twenty-five minutes we fell across the Indian Ocean, across the darkened continent of Australia, and shot into the night sky of the great Pacific basin. In our dive toward perigee,
Atlantis
gained back the velocity lost in the deorbit burn and added more. Shuttles achieved their peak speed on reentry, not ascent. The ride was as smooth and silent as oil on glass. The machine was on autopilot, with only her rear thruster jets active. Those were holding
Atlantis
’s nose 40 degrees high and presenting her wounded belly to the approaching atmosphere. Her aerodynamic control surfaces, the elevons on the wings and rudder on the tail, wouldn’t be able to hold her in attitude until we were much deeper into the atmosphere. If the rear thrusters failed, we would slowly drift out of attitude, tumble, and die. But an RCS system failure was far down on our lists of worries. The thruster jets were just smaller versions of the OMS engines, using a simple blow-down helium pressure feed system with propellants that burned on contact.

Hoot called the descent. “Mach 25.1…340,000 feet…Guidance looks great.” We were slightly faster than 25 times the speed of sound and at an altitude of 64 miles. Our little green bug was tracking perfectly down the center energy line. We were on course for Edwards AFB, still 5,000 miles away.

The atmosphere had thickened enough to become an obstacle to our hypersonic sled. Compression against
Atlantis
’s belly heated the air to a white-hot glow now visible from the front windows. I wondered what was happening underneath us. I had visions of molten aluminum being smeared backward like rain on a windshield. None of our instruments or computer displays showed
Atlantis
’s skin temperature. Only Houston had that data. I wondered if they would call us if they saw it rising. I hoped not. Such a call would definitely have us all tensed up as we died. Even Hoot wouldn’t be able to laugh away that MCC call. I looked at our displays and meters, not sure which would be the first to reveal a heat-shield problem. They were all in the green. Hoot would later tell me his eyes were never long from the elevon position indicators, certain a left-right split in those instruments would be the first hint the right wing was melting.

With the nominal displays I was happy to consider that our worries might have been misplaced. Maybe we had been alarmists. Maybe the damage was minor, as MCC had indicated. I still couldn’t believe that, but I prayed it was the case. I would have no problem offering the flight director, the CAPCOM, and everybody else an apology for having questioned their judgment.

“Three hundred ten thousand feet…still holding Mach 25…some Gs starting to build.”

Hoot didn’t have to tell me about the Gs. Dressed in my LES I had added more than sixty pounds to my body. My zero-G-acclimated muscles were finding it difficult to bear that weight against even a small G-load.

I looked upward through the top windows. As I had seen on STS-41D a snake of plasma flickered over us and slithered into the black. Periodically it would pulsate in incandescent-bright flashes that filled the cockpit like camera flashes. I wished I had paid more attention to the reentry light show during my
Discovery
mission. Wasn’t this plasma ribbon brighter? Weren’t those flashes more frequent? Was it
Atlantis
’s vaporized skin enhancing the show? There were no calls of distress from Hoot or Guy and the radios were mute. If the heat was dissolving
Atlantis
’s belly, the damage had yet to reach a system sensor.

At 240,000 feet and Mach 24.9 the guidance system commanded
Atlantis
into a 75-degree right bank. She was high on energy and the autopilot was pulling her off course to increase the distance to landing. In that extra distance we would have more time to descend. We trusted the autopilot to turn us back toward the Edwards AFB runway at the appropriate time. It was impossible for a shuttle pilot to look out the window at a featureless ocean from 45 miles high while still 3,000 miles from the runway and manually modulate the orbiter’s energy state. We had to trust the wizardry of accelerometers in
Atlantis
’s inertial measuring units to do that.

The plasma vortex intensified in brightness. I wondered how many earthlings were watching the celestial spectacle. The trail of superheated air would glow for many minutes after our passage. We were painting a white-hot arc from horizon to horizon to take away the breath of anybody watching, be they jungle island shaman or the crew of a supertanker.

The horizon came into view from Guy’s window. The Earth’s limb was tinted with the indigo of an impending sunrise.

“Mach 22 at 220,000 feet, a half-G.”

I wasn’t going to be able to stand much longer. My leg muscles were quivering. I had to get down the ladder to my seat. Before I left the flight deck, though, I craned my neck to see the Earth. The Sun had risen and painted a broken layer of clouds in flamingo pink. Just when I thought I had seen every “wow” scene in space, I was treated with a new feast for the eye. We were still traveling at a couple miles per second but had dropped to within forty miles of the cloud tops. The illusion was that we were accelerating, not slowing down. The clouds appeared to skim by at science-fiction speeds. The sight was a narcotic and I watched it until my zero-G-weakened legs couldn’t take my weight any longer and I collapsed to the floor. It was beyond time to get to my seat. I crawled to the mid-deck ladder like a wounded infantryman and felt with my feet for the ladder rungs. In slow, deliberate movements I worked my way downward and into my seat. By the time I was strapped in, I felt as if I had just descended the Hillary Step with a Sherpa on my back. I was exhausted from working in a G-force that was one half of the Earth’s pull.

I hated being downstairs. I was staring at a wall of lockers. There were no windows, no instruments. I felt claustrophobic. I could not imagine anything more terrifying than being in this room and hearing the death throes of a disintegrating shuttle while simultaneously having the lights and intercom go off, as had Ron McNair, Greg Jarvis, and Christa McAuliffe on
Challenger.
If the lights went dark and my intercom failed, I resolved to unstrap from my seat and try to climb upward so at least I could die looking out a window. There would be no reason to go to the side hatch and try our new bailout system. If I jumped out during aerodynamic heating, my body would be vaporized as quickly as a mosquito in a bug lamp.