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Space, the Final (Medical) Frontier


The New Physician January-February 2001
During the frenetic days of the space race’s 1960s Apollo missions, Dr. Joe Kerwin had won a place in the National Aeronautics and Space Administration’s (NASA) astronaut corps, but he had yet to secure a ticket into orbit. For years, he had been sitting in on the Monday morning pilots’ meeting at NASA’s Johnson Space Center, but to no avail. “I kept raising my hand for Apollo missions, and Al Shepard would say, ‘Put your hand down. You’re not going to the moon.’”

Shepard was right—Kerwin wasn’t going to the moon. Eight years out of medical school, the physician–astronaut had landed his position by way of a National Academy of Sciences (NAS) recommendation for NASA to recruit scientists as well as the fearless test pilots whose “right stuff” made them the cornerstone of early manned space flight. The NAS saw space exploration as more than just an environment for the daring to test their nerves: Space was a boundless laboratory, and physicians and scientists alike should have their place in it.

Of the first five scientists NASA recruited into the astronaut corps in 1965, Kerwin was the only physician. He had already logged in hundreds of flying hours as a navy flight surgeon, but this NASA selection allowed him to chase a bigger dream.

“When I was a kid, I would sit in the kitchen and eat…sandwiches and read science-fiction books. And my brothers would come in and say, ‘Ah, little Joe. He’s going to the moon someday,’” he says. And while he never did get to the moon, in 1973 Kerwin made one giant leap for the role of physicians in space.

“Now, here comes Skylab whose purpose was, among other things, was to determine whether humans can withstand long-term space flight,” he says of the U.S. space station that orbited Earth from 1973 to 1979. “So it suddenly became a biomedical mission, and it was what I was waiting for.” When he raised his hand to volunteer this time, no one told him to put it back down.

And so, on May 25, 1973, Kerwin became the second physician in space—he missed being the first, because a Russian cosmonaut launched into orbit just a few days ahead of him—and began NASA’s first serious study of zero gravity’s effects on the human body, work that continues today on the International Space Station. (See how space affects the human body, p. 13.)


So, welcome to the space doctor’s world—one that fluctuates between Earth and sky. Your job is to determine how to permanently put humans in a zero-gravity environment—a world where up is down and down is left or right. Confusing, huh? Well get this—even the organs you dissected as a first-year medical student are not where they should be as a result of this weightlessness.

It’s challenging work but easily linked to the practice of medicine. “The body was probably never meant to travel in space,” says Dr. Jeffrey Sutton, director of the National Space Biomedical Research Institute (NSBRI). “[But], medicine is all about physiology pushed too far. [Space medicine is] a really cool area because you have to think outside the box.”

In Kerwin’s day, there was barely a box to think outside of. “We were guided by the fragmentary, but interesting, data [about the human body] that had been gathered on astronaut flights from the beginning,” Kerwin says. But due to the brevity of early manned space flights, little was known about zero gravity’s long-term effects, and this knowledge was essential for NASA to have as it made plans to populate space and conduct interplanetary missions.

So when Kerwin and his two crew mates went to Skylab in 1973, it was to spend a month conducting research in life sciences, astronomy and other areas. While Americans were celebrating Memorial Day and pulling the lawn mower out of winter storage, Kerwin was using his medical background to study the weight loss, motion sickness and bone density reduction astronauts suffer. The crew performed aerobic exercises and measured changes in cardiovascular fitness; examined nutrition, creating a complete intake/output analysis for each crew member; conducted dental examinations; and investigated muscular capabilities.

Skylab reinforced NASA’s ability to conduct valid science in space, Kerwin says. “Suddenly we had a very sophisticated data set—still the best we’ve got.” Because the three Skylab missions were the last long-term, American-controlled space research missions, data gathered since then on numerous shuttle missions can only be applied to short-term flights, he says. “My personal experience in Skylab makes me proud of the good work we did. Since then we’ve been waiting—we’ve been doing a lot [of research], but we’ve been waiting [for another long-term research opportunity].”

Skylab wet the biomedical research whistle and established a role for physicians in space. Since then, 16 American physicians have made the trip on shuttle missions, trying to find answers to medical questions both 200 miles up and down here on Earth.

Dr. Drew Gaffney had been an associate professor at the University of Texas Southwestern Medical Center when he was recruited to be a payload specialist on Columbia’s 1991 mission, which was the first to be dedicated solely to life science research. Responsible for studying venous pressure in zero gravity, Gaffney became both scientist and subject on the mission, launching into space with a central venous catheter inserted near his heart so he could measure his blood pressure changes during the mission.

Circulation is a serious concern for astronauts because zero gravity prevents blood from flowing easily back into the extremities. “The blood hangs out in the head and chest and not in the abdomen and legs,” Gaffney says. Researchers expected that blood pressure would go up because of this, and Gaffney was surprised when the data indicated his pressure went down. “Quite honestly, I thought the system had failed,” he says, adding that he was so sure the data was incorrect, he reset the experiment’s entire system and checked it again. But the results were correct, and Gaffney says he finds satisfaction in the fact that he played a part in altering researchers’ thinking about blood pressure changes in space. “Having worked so long and so hard to get there, and then, by-in-large, having [the experiment] work was really satisfying.”

Just learning about the changes the body undergoes in space is not the sole challenge to physicians, says Dr. Bernard Harris, a physician–astronaut who journeyed into space in 1993 and 1995. “It’s going to be really important that physicians can [compensate for] these changes,” Harris says.

His work helped NASA get closer to the point where physicians can do just that. He didn’t fall into this business by accident; Harris says he had wanted to be an astronaut since childhood and chose medicine as his best way to get there.

His plan worked. In 1993 NASA sent Harris on a two-week mission to further study how living systems function in space. Harris spent time watching fish and tadpoles swim in circles—fish, like humans, have no concept of up or down in space, so they can’t swim in straight lines. He also served as the seven-member crew’s medical officer. NASA usually medically trains two crew members to tend to basic medical needs in space, but when physicians are on board, “we make the calls,” Harris says. (Crews are also supported by an on-ground flight surgeon. See “Physicians Without Wings,” p. 18.) “Every day is just like going to the doctor’s office,” Harris says. “You see common ailments—colds, muscle strains, headaches, diarrhea,” which, he adds, is even more uncomfortable in space than on Earth.

Kerwin had a similar experience with Skylab. “We had a general practitioner’s office capability in space. I couldn’t remove an appendix, but I could remove a tooth,” he says. “We could get back in 24 hours” if something more serious arose. “It’s sort of like camping in the Sierras,” he says—but at a much higher altitude, of course.

Harris spent more time in his high-flying exam room during his 1995 mission, which rendezvoused with the Russian space station Mir. Of the mission’s roughly 25 medical experiments, many focused on operational medicine. “In space, we don’t know what normal examinations are,” Harris says. “All of the windows for examining the organs are different.” For example, it doesn’t take a medical student to know that the heart is located down and to the left inside the chest cavity, so that’s where a physician would look for it on Earth. But physicians in space know that to find a crew member’s heart in zero gravity, they’ve got to steer their stethoscopes up and to the center because weightless organs float up.

But while in space, physician–astronauts don’t just examine crew members and conduct medical experiments; they also perform duties as astronauts. Both Harris and Kerwin went on space walks; Kerwin repaired a damaged Skylab heat shield during his.


Research related to space medicine isn’t only conducted in outer space, however. The NSBRI’s Sutton says NASA recognizes how the wealth of talent at U.S. medical schools can enhance its space program.

“As the International Space Station [ISS] became a reality, it became enormously urgent not only to solve the motion sickness problem but others as well,” says Dr. Bobby Alford, the NSBRI’s chairman. At 240 miles above Earth, the ISS operates in zero gravity, and astronauts staff the facility for four to six months, making the long-term effects of weightlessness a serious concern. “And NASA, having realized that, saw they needed to go about research in a new way,” Alford says.

NASA realized the results of some Earth-based life science research could be directed to aid the agency’s search for countermeasures, or solutions, to the physical and psychological effects of long-term space flight. So, in 1997, well before the ISS launched, the space agency established the NSBRI—a consortium of 12 schools engaging in NASA-sponsored research—to tap into and help direct the wealth of life science research already being conducted. The NSBRI is based at Baylor College of Medicine.

“The real influence and power in terms of the research institute is all of the researchers across the country,” Alford says. “If [NASA were] to try to establish or create the resources that all these research institutions have, they couldn’t possibly do it. It’d be too expensive.”

It makes for a great bargain for NASA. The NSBRI researchers have secured National Institutes of Health (NIH) and private foundation funding in addition to some of NASA’s financial resources. These outside funding sources are lured to the work because of the potential Earth benefits. (See “Down to Earth” p. 25.) “This is a bold, new era, and [the research] is absolutely essential if the human space program is to go forward,” Sutton says.

NASA also works with Vanderbilt University’s Center for Space Physiology and Medicine, whose biomedical researchers try to solve the physical ramifications of space travel.

Some of the countermeasures being researched could include a system to deal with the high-power bands of radiation astronauts are exposed to once they leave the Earth’s orbit. Gaffney, who now serves as the space physiology center’s associate director, says that in addition to the radiation concern, the bone and muscle atrophy that is inevitable in zero gravity and the psychological challenges of being physically isolated with a few other people for years at a time are the biggest problems requiring solutions from researchers.

Dr. Sam Pool, the assistant director of Johnson Space Center’s Space Medicine and Life Sciences Directorate, echoes Gaffney’s top priorities and adds several more. “We’d like a breakthrough in better being able to deal with the bone loss, which is one of the most serious problems. We’d like a breakthrough in the area of neurophysiology…; we’d like to have some surgical techniques which could be used in microgravity.”

The need for more extensive medical treatments comes from the fact that travel beyond Earth’s orbit promises to be years long. “When you go to Mars, you’re a long way from the nearest hospital,” Kerwin says. “You could be three years from the nearest hospital.” So researchers are working on medical technologies that are lightweight and can be used to treat any problem that might arise.

“We are at a threshold of having a suite of new technologies,” Sutton says. Sutton’s research focuses on generating on-going, passive monitoring systems that will help physicians on the ground treat medical problems a world or two away. “We’re interested in doing completely noninvasive treatments based on computerized models of individuals,” he says. One example is finding a way to monitor blood without ever using a needle, since having blood drawn in space is very uncomfortable for astronauts.


Many say the progression of countermeasure research is essential mainly because the future is here. The ISS maintains a continual human presence in space that we’ve never before had—in November, NASA celebrated its first anniversary of permanent space habitation. “Space will never have a time when humans are not there,” Harris says.

Space medicine has come a long way since Kerwin’s groundbreaking foray beyond our atmosphere. But the ISS is only a jumping-off point in NASA’s attempt to grab the golden ring: a successful manned mission to Mars. And to do that, many unanswered questions must have solutions in order to ensure the crew’s safety.

“We still don’t have a set of accurate countermeasures for people who spend a long period of time in that environment, and that makes the Mars mission rather difficult at best,” Pool says. “The development of countermeasures is very, very important.”

The ISS has always been considered the test environment for countermeasures, but with the station billions of dollars over budget and Congress weary of footing the bill, the station’s viability as a research laboratory is threatened. Plans for entire sections of the station have been scrubbed, and future crews have been scaled back from six to three people, which many experts say is barely enough manpower to keep up with routine maintenance. “Skylab was much simpler of a craft to fly,” Kerwin says, and he adds that the ISS should have a continual staff of at least six to complete the volume of research the station needs to conduct.

Many NASA officials and astronauts also express concerns over the Bush administration’s appointment of Sean O’Keefe to replace NASA’s former administrator, Dan Goldin. O’Keefe is better known as a management guru rather than as a space visionary. He served as the secretary of the Navy under the first Bush administration and, according to NASA flight surgeon Terry Taddeo, was known as “the Grim Reaper.” The current President Bush tapped O’Keefe for NASA while he was serving as the deputy director of the White House’s Office of Management and Budget.

“I’m worried right now based on the lack of knowledge [we have] about what Mr. O’Keefe is going to do,” Kerwin says. Many astronauts with whom The New Physician spoke are taking a wait-and-see approach. They say the potential for research cutbacks worries them, but there’s not much they can do about it. Kerwin says if O’Keefe can pull up NASA by its bootstraps into a better management plan, then “that’s great”—but other space experts have said the agency should not expect the wide-reaching, let’s-get-to-Mars-at-any-cost vision for which Goldin was famous.

Congress is also reining in its enthusiasm for the space agency as the ISS becomes increasingly expensive. “You can’t use the M-word in Congress right now,” Taddeo says of a Mars mission. “[NASA is] just like any other government agency. You’re there at the whim of the Congress and the president.”

But not everyone thinks NASA’s problem lies in expensive ideas and not enough money to pay for them. “The bottleneck, in my opinion, is not money, it is risk,” Sutton says. “Since [the] Challenger [explosion], we have been in a risk-averse culture. As a society, we have an expectation that we’re going to go up, and everything will be fine.” But this is impossible, he says, because NASA can’t screen astronauts for every potential medical problem, given the years needed for interplanetary travel. No matter where people go, they will get sick, Sutton says. “If you put seven people in their 40s and put them away for a year, people will become ill. There will be things that arise. That is just the human condition.” So, he says, we’ll never be able to avoid all of the risks of long-term space travel, a fear NASA—and society—will have to overcome if the space program is to continue on its current path.

However, for those who work in space medicine, the future is still starlight bright. “If you’re a space nut like me, the most exciting thing there is…is putting people in systems to go to Mars,” Kerwin says. “The challenge is out there, and we know we can do it.”
Jennifer Zeigler is a senior writer with The New Physician.