Hoping to keep its space jockeys from soiling the cabin, NASA had supplied each astronaut with what Gaffney calls an elegant barf bag-- complete with cloth upper container, plastic sack, and wet wipe for cleaning up. But technology has its limits, notes Gaffney. The problem, of course, is that the stuff doesn’t fall. It’s in your nose and your mouth. It’s really gross. Fortunately, the most acute effects of motion sickness were eased by the medication within 30 minutes; the balance of Gaffney’s symptoms disappeared over the next four days.
As he went about his work on that first day in space, Gaffney recalls blowing up like a balloon. He was the living embodiment of fat- face, chicken-legs syndrome. Yet the reading from his catheter remained consistently and mystifyingly below normal pressure readings on Earth. This would later give Blomqvist’s team plenty to chew over on the ground. But Gaffney had little time for contemplation; he was too busy in his many roles as astronaut, investigator, and research subject. As scheduled, his catheter was withdrawn nine hours into the flight, having fulfilled its purpose.
Most of the experiments took place inside Spacelab, which was stowed in the shuttle’s cargo bay. The $140 million reusable module measures 23 feet by 16 feet, about the size of a bus, and is accessible through a pressurized tunnel from the crew compartment (the astronauts commute by air, literally flying through the tunnel). For this mission the module was outfitted with the sort of equipment that might be found in any good medical school physiology lab: it included cell incubators, ultrasound and ekg machines to study heart size and function, a device to measure body mass, an exercise bicycle to assess heart and lung performance under stress, and a mass spectrometer to analyze exhaled gases.
The astronauts carried out their experiments at a relentless clip, with a daily schedule budgeted in five-minute increments. They drew blood samples to study the effects of spaceflight on different types of blood and immune cells. By inhaling tracer gases, then blowing into tubes while on the exercise bike, they provided data for lung and heart function studies. As part of the fluid-shift studies, they also rigorously logged everything they ate and drank, weighed themselves daily, and collected urine, as Gaffney puts it, on a void-by-void basis. (It’s known that when receptors around the heart sense blood volume rising, they promptly tell the kidneys to dump fluid. So it was thought that astronauts tended to urinate more in space because of the fluid shift that occurs in zero-g.)
The experiments with rats and jellyfish--involving observation during flight, tissue sampling and dissection afterward--complemented the human trials. One aim was to determine whether the animals provided a good model for human responses to weightlessness. Jellyfish, for example, were selected because their gravity sensors, similar to those in the human inner ear, might offer clues to the origins of space sickness. On Earth jellyfish swim up and float down; in their sealed plastic bags and bottles on Spacelab they moved in confused circles. Rats, observes Gaffney, didn’t seem to enjoy drifting about in their cages, either. They were happier when the humans on board took them out of their cages and cuddled them.
The crew had barely begun their laborious regimen of experiments when their lab freezers started breaking down. The freezers, needed to preserve the crew’s frozen samples of blood and urine, took turns warming up, threatening the mission with meltdown. After feverish consultation with ground experts, the crew managed to save the biological materials by shuffling them back and forth between freezers while defrosting, then restarting one machine at a time. But the round-the-clock rescue effort further cut into the increasingly weary crew’s sleep.
Even before the freezer incident, Gaffney was struck by how difficult it was to sleep. Everybody’s watched 2001, he told a medical school audience recently. You think space is quiet. Well, it’s like a boiler factory inside the shuttle. Radios, pumps, and fans produced a din of up to 75 decibels even in the relative still of night. Cabin lights were another problem. Some of the astronauts wore blindfolds when they went to bed.
After seven days in space, with the main experiments largely completed, shuttle commander Bryan O’Connor persuaded NASA administrators to give his exhausted crew a break. Space is a wonderful place to play, Gaffney says, recalling his few hours of respite. Now accustomed to their floating life-style, the astronauts stacked themselves on top of one another and performed six-layer push-ups.
Columbia’s touchdown at Edwards Air Force Base in California three days later was flawless. But the effects of the trip were far from over. For astronauts, readaptation is often traumatic--next to space motion sickness, the most debili-tating part of space travel. And it’s all the product of the fat-face, chicken-legs syndrome.
While volume depletion triggered by the fluid shift is no problem in the weightless environment of space, it can cause no end of trouble upon the return to Earth. As you might expect, Earth’s gravity reverses the fluid shift, redirecting more blood to the legs. With less blood in the body as a whole (and more of what’s available in the lower half), the heart may not always be capable of pumping enough blood up to the brain. The result is dizziness or fainting when a newly returned astronaut tries to stand (a condition called orthostatic intolerance). Muscle disuse and atrophy from the cushy life in zero-g make the transition even more difficult.
Eager to study the painful readjustment, researchers greeted the crew with an airport people mover and plucked them off the shuttle in record time; they were on their way for more testing 26 minutes after hitting the tarmac. Used to floating effortlessly about Columbia’s cabin, the astronauts now found it difficult to even rise out of their seats. It’s quite a shock, says Gaffney. The first time I pushed myself up, I felt like I was lifting three times my weight. You’re in that heavy orange flight suit, and your muscles are really weak, and you’re kind of staggering down the steps. And then you’re whisked out to the experiments. Gaffney and three other astronauts remained in California for six more days of medical testing.
The various research teams that designed the experiments aboard Columbia say it will take years to complete the analysis of all the data collected on the mission. But three months after the shuttle’s return to Earth, the principal investigators began discussing their initial findings.
To Blomqvist, Gaffney’s low central venous pressure upon entering zero gravity was a bombshell. With fluids shifting to the upper body, he expected the reading to be higher than on Earth, not lower. He now speculates that the shift actually began on the launchpad, during the cardiologist’s four-hour wait for lift-off in the legs-up, head-down position. Because Gaffney was upended, his fluids started moving to his chest, initiating his body’s efforts to reduce the increased venous pressure. Excretion was one reaction, but there may have been others. One possibility, for instance, is that Gaffney’s blood vessels dilated while waiting for lift-off. If you relax the blood vessels to make them floppier and stretchier, explains Gaffney, then you’ll still have the same amount of blood in your system but the pressure will fall. Thus some of the adaptation that’s been ascribed to space apparently occurred on Earth. By sheer fluke, it seems, the traditional lift-off position primes the human body for spaceflight.
Blomqvist’s observations, however, do fit a general pattern emerging from Columbia’s mission, suggesting that the body adapts to zero gravity far faster than anyone expected. Researchers from Baylor College of Medicine in Houston, for example, found shifts in kidney function and a drop in red blood cell production within 24 hours of lift-off. Because of fluid excretion, blood volume initially dropped by as much as 20 percent, raising the relative proportion of red cells in circulation. Researchers now think that the kidneys, sensing the blood was getting thick and sludgy with cells, sent signals to slow down red cell production.
Other experiments confirmed what had already been suspected. White blood cells, which fight infection, became less responsive. Muscles atrophied from disuse. Levels of calcium and other bone minerals declined when limbs no longer had to work against gravity. All these problems, however, gradually reversed themselves on return to Earth. NASA officials say nothing uncovered in the Life Sciences Mission suggests that humans could not survive a lengthy flight, such as a trip to Mars, though countermeasures, such as artificial gravity, may be necessary to avoid permanent damage.
His astronaut days now over, Gaffney has resumed work as a cardiologist at the medical school. Not that he wouldn’t fly again: If I had the chance to do a long-duration flight or to do different experiments or to fly with the Russians, I would go tomorrow, he says. But he and Blomqvist remain involved in planning future missions (Spacelab Life Sciences 2 is now scheduled for July 1993). Two junior members of their team have decided to apply for the payload specialist program, in the hope that, like Gaffney, they can someday conduct their own research among the stars.