Above & Beyond: No Way Out
- By Thomas D. Jones
- Air & Space magazine, July 2002
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.
After two hours of futile attempts, and with no obvious avenues of attack to pursue, mission control advised us to hang up our spacesuits for the day.
Thanksgiving dinner aboard Columbia that night was a gloomy affair, all of us struggling to find reasons for optimism while skirting our frustration. Like me, Tammy was deeply disappointed over our mission’s first significant setback. As EVA lead, she felt keenly not only her own lost opportunity but also the impact on our colleagues, who’d worked for months to train us and build the test hardware. The holiday menu of rehydrated shrimp cocktails, Dinty Moore turkey dinners, and warm tortillas couldn’t disguise the bad taste of failure.
Next morning, we expected to wake to news that Houston had found the key to the problem and that we’d be headed outside later in the day. Instead, we spent the day taking measurements around the hatch’s interior surface, looking for a misalignment. Tammy and I fitted makeshift tethers to a crowbar and mallet from Columbia’s toolbox, confident we could “nudge” open the hatch on our second attempt. But Houston’s wake-up music on November 30, the Doors’ “Break on Through to the Other Side,” couldn’t soothe the sting of learning that our mission’s two EVAs had been scrubbed.
NASA managers made the right call. If we’d forced open the hatch and then couldn’t reseal it on the way back in, we’d be marooned on the wrong side of a pressure bulkhead. To save us, our crewmates would have to execute an emergency reentry with us in the airlock, leaving the multi-million-dollar ORFEUS/SPAS ultraviolet spectrometer telescope we’d deployed on launch day stranded in space.
As our 18-day mission wound down, our spirits slowly rebounded. Our two science satellites had performed superbly, and I was in orbit, weightless, blessed with good companions and incomparable views of Earth and space. Thanksgiving had indeed come to Columbia’s crew—just a few days late.
Strapped in for reentry, the one fear Tammy and I still harbored was the embarrassing possibility that once back on Earth, the hatch would open—normally. Just the thought of it made me shiver, despite the furnace-like plasma surrounding Columbia as we plunged back to Earth. It wasn’t until a couple of days after touchdown that we got the welcome word from the Cape—the hatch was still jammed. X-rays showed a small screw missing from the handle’s sealed gear train. When engineers tore down the mechanism, they finally solved the mystery: The loose screw had floated into the gear teeth and remained trapped there in sticky lubricant. The half-inch-long screw had jammed the gears like a chock thrown under an aircraft tire.
NASA quickly imposed new inspections and tests to prevent future hatch problems. And to our great relief, chief astronaut Bob Cabana promised he’d do his best to get us another shot at an EVA. Tammy Jernigan broke on through in 1999, with nearly eight hours of construction work outside the International Space Station. As for me, a little over four years after the turn of our screw, I opened Atlantis’ hatch on STS-98 and floated gingerly out into the brilliant sunlight in the shuttle’s payload bay. It was a grand entrance, one to be savored for a lifetime. Fittingly, on my office wall today hangs a photo of Tammy and me in our suits—mounted next to my half of the offending screw.
—Thomas D. Jones