Back to Front PageVOLUME 6, NUMBER 4

Out of This World: Scientists Pave the Way for Extended Space Travel

By Barbara A. Gabriel

Researchers on the NSBRI's neurovestibular adaptation team use eye movements produced by moving stripes to evaluate inner-ear function.

On Sept. 26, 1996, astronaut Shannon Lucid, Ph.D., made history when she returned from the Mir Space Station after having logged 188 days in space, establishing the U.S. record for the most flight hours spent outside the Earth's atmosphere. While her endurance record captured the imagination of the American public, Dr. Lucid's subsequent adaptation to Earth's gravity after remaining weightless for six months was of special interest to NASA scientists concerned with the not insignificant physiological consequences of long-term space travel on the human body. With their sights set on even longer duration flights beyond Earth's orbit, NASA in 1997 established the National Space Biomedical Research Institute (NSBRI) in order to apply the expertise of several of the nation's top medical schools to space travel-related biomedical research.

A consortium of seven schools headed by the Baylor College of Medicine, the NSBRI was among several competing groups responding to a request for applications issued by NASA with the goal of establishing an integrated research initiative into the physical challenges astronauts face during long-duration space travel. The seven original consortium members - Baylor, Harvard Medical School, Johns Hopkins University School of Medicine and Applied Physics Laboratory, Massachusetts Institute of Technology, Morehouse School of Medicine, Rice University, and Texas A&M University - were joined by five others in 1999, bringing the total number to 12. The new members - Brookhaven National Laboratory, Mount Sinai School of Medicine, University of Arkansas for Medical Sciences, University of Pennsylvania Health System, and the University of Washington - were likewise selected for their proven excellence in biomedical research.

Bobby R. Alford, M.D., executive vice president and dean of medicine at Baylor College of Medicine, also serves as chairman of the board and chief executive officer of the NSBRI. "The institute's mission is to carry out research aimed at countering the critical risks associated with space flight in terms of human function, such as muscle atrophy, bone loss, and radiation exposure," he explains. NASA funding of NSBRI projects - totaling $26.7 million this year - is awarded to researchers both inside and outside the consortium on a peer-reviewed basis. Currently, 87 research projects in 71 institutions involving 252 researchers are being carried out under the auspices of the NSBRI.

The research efforts of the NSBRI are divided into a unique network of 12 theme-based teams - including ones on bone loss; cardiovascular alterations; and immunology, infection, and hematology - directed by team leaders who coordinate the efforts of individual investigators. Kenneth M. Baldwin, Ph.D., professor of physiology and biophysics at the University of California at Irvine College of Medicine and leader of the NSBRI's muscle alterations and atrophy team, explains that his role as team leader is to create a synergy among researchers at different institutions "so that the sum of the parts is greater than the individual components."

The following 12 teams make up the research efforts of the NSBRI: Bone Loss •Cardiovascular Alterations •Human Performance Factors, Sleep, and Chronobiology •Immunology, Infection, and Hematology •Integrated Human Function •Muscle Alterations and Atrophy •Neurobehavioral and Psychosocial Factors •Neurovestibular Adaptation •Nutrition, Physical Fitness, and Rehabilitation •Radiation Effects •Smart Medical Systems •Technology Development

Dr. Baldwin says this synergy is also taking place between his team - which focuses on the loss of muscle mass, strength, and endurance that occurs during space travel - and the bone loss team, which is trying to counteract the rapid decrease in bone mass that also occurs during weightlessness. Both teams are studying the boss loss and related muscle atrophy that strike spinal cord injury patients. "Like astronauts, these individuals don't weight-bear and their bones rapidly atrophy as a result," Dr. Baldwin explains. "But equally important is that these people also lose muscle mass. Together, our projects are looking at whether restoring bone will also prevent the loss of muscle."

Like the muscle group, the bone loss group is exploring both motor movement - such as pedaling a type of bicycle that creates G-forces and thus stimulates hypergravity - and pharmacological interventions. Mitchell Schaffler, Ph.D., professor of orthopedics, cell biology, and anatomy, and director of orthopedic research at the Mount Sinai School of Medicine, is examining the possible application of drugs used to treat post-menopausal osteoporosis to minimize the rapid bone loss associated with space travel. Dr. Schaffler is also interested in maintaining bone's material properties in a zero-gravity environment. He believes the normal weight-bearing activity that occurs on Earth is vital to a skeleton's healthy makeup. "Not only is the amount of bone a determinant of fragility, but it is also conceivable that changes in the bones' material properties can make them more fragile and brittle," he surmises.

Such research has clear applications to Earth-bound medicine. While Dr. Schaffler hopes his studies lead to more effective tools against osteoporosis, Dr. Baldwin sees his research as adding to the body of knowledge about muscle wasting. "As individuals go beyond their fourth decade, there is a continuous and rapid decline in muscle mass," he explains. "The question is whether this process is age-related or inactivity-induced, since people tend to be less active as they get older."

Newly added NSBRI research teams go beyond the examination of physical changes to explore other areas that will be critical to extended space missions, such as the study of psychosocial elements that arise when individuals are confined to small environments for long periods of time.

Another team is developing "smart medical systems," or new methods of remote medical diagnosis and treatment in the event that an astronaut requires medical attention. "The two recent incidences in the Antarctic in which scientists had to be air-lifted for medical treatment highlight the need for such systems for people working in hostile, remote areas," says Dr. Alford, who is confident that NSBRI research will benefit Earth-bound patients. "Looking back on what NASA has already contributed to science and technology through the necessity of finding new approaches to existing problems in challenging environments, I think we can expect similar breakthroughs from our research teams."

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08 August 2001