Extreme Medicine (20 page)

Tonight was the first time in this mission that
Atlantis
had been fueled, ready for launch. The perimeter had been evacuated as far back as two miles to all but the most essential staff.
Atlantis
was dangerous now; the potential energy stored in the chemicals of her external tank and the solid fuel of the rocket boosters was enough to propel the two thousand tons of stack into space at twenty-five times the speed of sound. The groaning, the creaking, and the hissing may have been caused by expanding gases and grating metal, but even the more seasoned engineers regarded
Atlantis
as though it were an animal slowly coming to life, with a personality of its own.

The countdown clock ticked down to zero. We stood and watched as
Atlantis
rose into the sky. It felt wrong. Launches always did. It was an event on a scale that didn't otherwise exist in the world. A massive object racing straight up, far faster than it should be able to, burning engines bright enough to light the entire bank of clouds into which it eventually flew, disappearing in seconds. I stood, breath bated, until the solid rockets separated.

The crew on board knew the risks of their endeavor better than most. As you climb on the highest slopes of Everest, there are points at which you pass the bodies of people who have died on the mountain—a sobering reminder of the consequences of taking such risks. In a similar way, astronauts riding aloft are aware that as they hear the words “go at throttle up,” they are passing the point at which
Challenger
failed, and they know as they decelerate through Mach 19 on reentry, that
Columbia
got there—and no further.

—

T
HE TRICK TO FLYING IS TO
throw yourself at the ground and miss. At least that's how Douglas Adams explained it in
The
Hitchhiker's Guide to the Galaxy
. While his description was constructed for comic effect, it actually captures—in a strangely accurate way—what astronauts heading into orbit actually do. They climb into vehicles, fire their rocket engines, and hurl themselves across the Earth so fast that they run out of planet to fall onto. Once at that speed, they continue to fall freely around the globe, held by the bond of gravity, unable to escape Earth's grip or return to its surface. The term
orbit
simply describes the act of falling toward a celestial body without ever hitting it.

There is, of course, a little more to it than that. The art of rocket science is a discipline filled with everyone's worst math-class nightmares: calculus stacked upon the mechanics of circular motion framed within exotic coordinate systems. When you get down to the nitty-gritty of building the things, there's a load of pretty nasty chemistry to bend your mind around, too.

The reality is worse still. The stuff on paper has to be engineered to work in the real world without all of the simplifying assumptions. The nuts and bolts have to travel at many thousands of miles an hour and then fall gracefully through space, precisely as predicted, without flaw or failure. The only way you could make rocket science any more daunting as a prospect would be to add humans into the equation as passengers.

This is the challenge of human spaceflight. No amount of adaptation or acclimatization can prepare the body for exposure to hard vacuum. No amount of augmentation of physiology can make that environment survivable. Instead bubbles of life support must be artificially created, maintained, and sealed against the exterior. These must then be crammed intact into the architecture of a space vehicle, small enough and light enough to respect the great energies demanded by orbital spaceflight but spacious enough to afford at least rudimentary comfort for the crew. When it comes to human spaceflight, throwing yourself at the ground and missing is only half the battle.

—

A
S A JUNIOR DOCTOR,
I'd occasionally get a chance to spend some time at the Cape, working and researching with the medical team there. Formally it was Kennedy Space Center, NASA's spaceport, the point on Earth from which every human-rated American space vehicle had ever departed. But to me it was always the Cape. It sat a few dozen miles outside Orlando on the eastern seaboard of the United States, a sprawling government complex reclaimed from wet marshlands in the 1960s for the purpose of doing something outrageous with explosive rocket technology.

From time to time, NASA ran training courses for the civilian medical teams who might be called upon to attend a shuttle accident. We'd gather in lecture halls and receive instruction on the anatomy and physiology of the space shuttle, how it might fail, and what, in theory, we might do to help.

They showed us how the crew could escape a debacle on the launch pad by sliding down a two-hundred-foot-high zip wire, getting from the crew deck to the ground in a few short seconds, crashing into a net, and then bailing into an armored car that they'd been trained to operate. In an emergency, they were told to climb in, drive straight through the perimeter fence, and keep going in the hope that they might outrun the fireball and blast that would accompany the simultaneous detonation of a few hundred thousand liters of rocket fuel.

They showed us too that the shuttle could abort after takeoff during its ascent. Redundancy was the name of the game here. After a few minutes of flight, the mission could tolerate the failure of one of the three shuttle main engines and still get into space, albeit at a lower than intended orbit.

Losing an engine early, before momentum had had time to build, or losing more than one engine, would be a different matter. Unable to develop the altitude or velocity required to achieve low Earth orbit, the shuttle could perform a transatlantic abort, a maneuver in which it would ditch its external tank and solid rocket boosters and vault across the Atlantic Ocean, landing somewhere in Europe.

That journey across the Atlantic Ocean of more than four thousand miles, which a commercial airliner would take perhaps eight hours to cover, would be completed by an aborting shuttle in less than thirty minutes.

There was another, even more outlandish scenario called the return to landing site (RTLS). Here, having lost an engine early in the launch, unable to make it to space, but still strapped to its external tank and two solid rockets, the shuttle could—in theory—be flipped over and flown back to Kennedy Space Center. During this abort, the solid rocket boosters would be jettisoned after two minutes. Then, still strapped to the external tank and at this point heading toward Europe at several thousand miles an hour, the shuttle would ascend and use its maneuvering thrusters to flip itself over, rotating through 180 degrees like a pancake, with its remaining main engines still burning.

Having performed the equivalent of a supersonic handbrake turn, the shuttle's momentum would continue to carry it toward Europe.

Flying backward with its nose pointing roughly toward the United States, the engines would be facing the direction of travel, thus slowing the shuttle down. At some point, the rocket motors still firing and the external tank still attached, the shuttle's progress toward Europe would be arrested. Momentarily it would come to a standstill before accelerating once again, this time back toward the States. The crew would then dump their external tank and attempt to glide unpowered back to the site from which they'd launched some twenty-five minutes earlier.

It wasn't just failure of the engines that could lead to these emergency aborts. Both the transatlantic abort (TA) and the return to landing site could also be used to get the shuttle back on the ground quickly if a significant failure in the life-support system occurred. There was, after all, no point in parking a vehicle in perfect orbit if the crew inside could not be kept alive.

A peppering of euphemisms accompanied these briefings. There was an anticipation that under such conditions, both the vehicle and its crew might return in “suboptimal condition,” that the landings might be “off nominal” in character. Behind this technical phraseology lay the risk that during an abort the shuttle might crash on or short of the runway and the crew might be severely injured in the process.

To civilian clinicians, these abort modes sounded like the stuff of science fiction. Even among the astronaut corps, there was a little skepticism about just how successful a real RTLS abort might be. Nevertheless, they dutifully drilled and trained for the scenarios, sitting fully suited in simulators for hours at a time, rehearsing their worst nightmares.

I often wondered why they bothered to do this when the risk of these types of failures was so low and the chances of recovering intact after one of the more elaborate aborts was smaller still. But like so many other things in exploration and medicine, they did it because the only other alternative would have been to do nothing—which for them wasn't an option at all.

—

E
VEN IF THE LAUNCH GOES SMOOTHLY,
there is still the possibility that a medical emergency might arise during a mission, far from the safety of any hospital. Because of this, considerable effort has been invested in designing avenues of escape and medical contingency for space crews. People have even gone so far as to devise ways of resuscitating victims of cardiac arrest. This is no mean feat. Imagine, for a moment, trying to deliver cardiac compressions while floating weightlessly in orbit.

The trick, it turns out, is to strap the patient to the floor of the vehicle, put your hands on the person's chest, brace your feet on the ceiling, and then use your legs to provide the necessary force. This method has been tested on resuscitation dummies in weightless training aircraft, and it works surprisingly well. But if you're going to plan for the possibility of cardiac arrest, then you've got to consider precisely what you're going to do after the patient's heart starts beating again. Contrary to what Hollywood would have you believe, people who survive an arrest of their heart very rarely sit up the instant their pulse returns as though nothing had happened. The experience of total circulatory arrest, along with whatever it was that stopped the heart in the first place, tends to leave one critically unwell. Afterward, a period of extreme instability and a lengthy stay in an intensive-care unit is the norm. For all its sophistication, the International Space Station has less medical equipment and its crew less expertise than are found in the average ambulance. Definitive medical care is available only back on Earth.

It was predicted that during its operational lifetime, there would be at least one major medical incident aboard the International Space Station that would require evacuation to Earth. To allow for this, NASA started work on a new experimental vehicle: the X-38. Standing on the edge of space, looking out across the vastness of the final frontier, NASA was still prepared to go to extraordinary lengths in the hope of saving a life.

—

T
HERE IS A BLACK-AND-WHITE PICTURE
from 1977 of the prototype space shuttle
Enterprise
being carried along a Californian desert road on the back of a huge articulated truck, being delivered to NASA's Dryden Research Center for flight testing. Behind it is a snaking line of 1970s motor vehicles. In the foreground sits a man astride his horse, its breath misting in the cold February air. It is a picture of the old world watching the future arrive. That is what we came to expect from the space agency. That's what NASA did: It served up the stuff of science fiction on the back of a flatbed truck and told you that
this
was what the future was going to look like.

I was reminded of that image when someone showed me the plans for NASA's new X-38 back in 2001. It was a wingless vehicle, shaped like a shuttlecock split in half through its nose; a wedge too narrow to allow an adult to stand upright inside, about the size of a luxury speedboat. It was windowless and profoundly alien in appearance. I remember thinking that if it landed unannounced in your back garden, you'd be pretty disappointed if something didn't then slither out and say, “Take me to your leader.”

The X-38 was destined to be NASA's Assured Crew Return Vehicle—a way of solving the problem of what to do if an astronaut crew had a really bad day in space. The plan was to load it into the payload bay of a space shuttle, deliver it to the space station, and then leave it docked until called upon.

In the event of some catastrophic failure of systems aboard the space station, the X-38 would become a space lifeboat. The crew would scramble inside, lie down, strap in, and punch out. It was a remarkable design, able to accommodate a crew of seven, shaped so that it could be steered in the upper atmosphere while traveling at hypersonic speeds, and then endowed with the world's largest parafoil—a steerable canopy that would slow its descent to the ground to ensure a gentle landing. But it was intended to be more than just a fast ride home. In a medical emergency, with members of the crew critically ill or injured, it would essentially perform as a space ambulance, capable of being equipped with medical oxygen, state-of-the-art patient monitoring, and even ventilators.

But as costs mounted and the International Space Station ran into financial trouble, NASA was forced to make cuts. The X-38 was shelved, and NASA returned to relying upon the Soyuz space vehicle as their means of escape. Much smaller than the X-38 and capable of accommodating only three crew members at a time, it was a lifeboat with no real medical capability. But in low Earth orbit, it had become increasingly clear that the dominant threat to human life would not come from crew injury or malfunctioning physiology. There was something that doctors and mission controllers on the ground feared far more than any medical emergency: a catastrophic failure of the vehicles that carried and protected their astronaut crews.

—

S
OYEON DIDN'T PLAN ON
being an astronaut. She lived in South Korea, a country with no human space exploration program. She watched science-fiction films as a child and fantasized idly about the possibilities of space, but her ambition went no further than that.