Space shuttle Columbia, Thanksgiving day, 1996. Astronaut Tammy Jernigan grasped the airlock depressurization valve. She rotated the black knob to the open position; air began whistling from the chamber directly into space. Hovering above her spacesuit’s backpack, I glanced down at the digital readout on my own suit and watched the pressure in Columbia’s cramped airlock creep toward zero.
The countdown to our first extra-vehicular activity, or spacewalk—a high-profile test of space station construction techniques—had gone perfectly thus far. We’d spent the morning hustling through the preparation checklist with veteran spacewalker Story Musgrave, our choreographer and taskmaster. He’d guided us through every detail of suit-up, checking and double-checking; about 30 minutes ago, he’d closed the hatch into Columbia’s middeck behind us. Tammy and I were on our own.
Racing through our minds were the details of the six hours of work that lay ahead. At the old WETF—Weightless Environment Training Facility—at NASA’s Johnson Space Center in Houston, Tammy and I had put in more than 130 hours underwater in our bulky suits, rehearsing within the submerged mockup of the shuttle payload bay. In each grueling session, we’d run through a tightly scripted series of tests: putting a new space station cargo crane through its paces, demonstrating the replacement of a dishwasher-size solar array battery, and working the kinks out of nearly a dozen new tools. The WETF runs seemed endless, and we could hardly believe it when we wrapped up the last rehearsal and climbed from our dripping suits for the last time. Now we were wearing the real thing, about to go to work in earnest.
When the airlock pressure reached five pounds per square inch, Tammy halted the depressurization for a spacesuit leak check. Her suit pressure was a trifle high, but her breathing would soon remove enough oxygen to bring the reading within limits. My pressure gauge was right on the money at 4.3 pounds per square inch—in a pure oxygen atmosphere, that’s all the pressure needed to fully charge our blood with oxygen. Tammy twisted the depress valve wide open, and the remaining air molecules fled into the void outside.
Still connected to the orbiter by our suit umbilicals, we got the “Go” from Story to open the airlock hatch. The butterflies in my stomach were all in full zero-G flight; I was more fearful of making a mistake outside, in front of my colleagues, than of micro-meteoroids, searing temperatures, and hard vacuum. In a moment we’d be out the door and really “on stage.” With one hand on the yellow handrail rimming the outer hatch, Tammy grabbed the hatch handle and cranked it clockwise.
The handle jerked to a stop after about 30 degrees of travel. As she put more muscle into the move, her body swung toward me, the force reacting back through her arm and torso. At first I thought it was just a sticky spot in the handle travel, but after half a dozen straining attempts—I could hear her breathing with effort over the intercom—she couldn’t get the handle to move any farther. “Tom, it won’t budge,” she said. “Swap places with me. You have a go at it.”
I squeezed by Tammy, floated some bobbing tools out of the way, and grabbed the handrail for leverage. Then I shoved the forged-steel handle clockwise. Thunk. It smacked solidly into some obstacle at the 30-degree mark. After several grunting attempts to force the handle around, I could see we had a struggle on our hands. We were nowhere near turning the handle the one full circle required to retract the metal rollers that held the hatch against its seals. There was nothing obvious in the way, yet the handle felt like it was jamming against a hard metal stop. Unlike a sticky gasket or some frozen lubricant in the gears, this kind of hardware problem was new to both of us.
Pivoting to face Tammy, I caught her glance behind her helmet faceplate. She shook her head in amazement, and both of us mouthed silent oaths of disgust. In words pitched with disbelief, she described our predicament to Story and asked for help. We were in a surreal situation: Just an eighth of an inch of aluminum separated us from the experience of a lifetime.
The word went down to Mission Control. We could just imagine the stunned reaction there. Our flight director would be glaring at our instructor, Glenda Laws: “You’re telling me they can’t get the door open?!” As we discussed the problem with Houston, Tammy and I each tried again to exert maximum leverage on the stubborn handle. Nothing. The EVA team on the ground had us try everything they could think of—even the obvious. I could hear the apologetic tone accompanying capsule communicator Bill McArthur’s mandatory question: “Tom, uh, please confirm you’re turning the handle in the clockwise direction?” I’m sure he winced at the impatience in my voice as I snapped, “Affirmative!”
The two of us scrambled for a position that would help us deliver more torque to the handle. Trying for more leverage, I got a boot on the end of the handle and strained against it, bracing my gloved hands against the ceiling, but Houston quickly called me off that technique, fearing that that much force could damage the gears and linkages in the hatch mechanism. Next mission control had us disconnect the handle from the gear housing and inspect it for debris or damage—nothing out of order. Tammy and I were in no danger—we were using Columbia’s oxygen and electricity, and we had hours of carbon dioxide scrubber capacity left—but we refused to admit there was a possibility we would not get the hatch open. No shuttle hatch had ever malfunctioned. Though we’d trained underwater to free a jammed hatch linkage from the outside, we never dreamed we’d be unable to get it open from the inside. Everything we could see from within our closet-size airlock was maddeningly in order, and our crew’s video survey of the hatch exterior showed nothing amiss.