Biomedical research in space has yielded a wealth of insights into the effects of weightlessness on the human body, but recent funding cuts undermine the ability of the United States to continue to contribute to the field of space medicine, writes Millie Hughes-Fulford, PhD, a biologist at the San Francisco VA Medical Center and a former NASA astronaut.
In observation of the final U.S. space shuttle mission in July, 2011, Hughes-Fulford, an adjunct professor of medicine at the University of California, San Francisco, reviews advances in space medicine over the last 60 years in The FASEB Journal (Sept. 1, 2011).
Hughes-Fulford begins her review with mentions of fictional accounts of space travel published by Jules Verne in 1865 and H.G. Wells in 1901, works that she describes as “the starting point of … the dream of space exploration.” After World War II, she explains, the United States and Soviet Union made that dream a reality through the development of powerful spacecraft based on rocket technology invented by Third Reich scientists. The two nations’ efforts resulted in the creation of intercontinental ballistic missiles and rockets capable of escaping Earth’s gravity field.
Research on the impact of space on the human body, writes Hughes-Fulford, started in 1957, when the U.S.S.R. initiated the space race with the launch of Sputnik 1, the first human-made object to be placed in orbit. In their intense competition to be the first nation to send a human into space, both the U.S. and U.S.S.R. placed animals aboard spacecraft and sent them into space to test the sustainability of life during space flight. The first live being to orbit the planet was Laikia, a dog, launched by the USSR in November 1957. Such experiments “started the fields of gravitational and space biology,” according to Hughes-Fulford.
Later flights with human crews, she writes, were used to study the effects of weightlessness on the human body. She notes that crew members of the three-man US Apollo missions were “the first to show significant changes in multiple biological systems in spaceflight.” Those changes included heart irregularities, anemia (decrease in red blood cells), bone loss and a high rate of infection during and after flight.
The biological effects of microgravity were studied in detail in 1973 and 1974 on Skylab, the first manned orbiting laboratory, which was developed and launched by NASA. Skylab experiments revealed for the first time the extent of immune system changes in space, when T cell function lost by Skylab crew in orbit did not recover until almost two weeks after their return to Earth. It was also observed that crew members’ bone loss increased with the length of time they spent outside Earth’s gravity field.
In 1991, Hughes-Fulford, herself, was a crewmember on STS-40, the first US space shuttle flight dedicated to life sciences. The flight featured experiments designed to further probe the effects of weightlessness on the body.
In the years since her return from orbit, Hughes-Fulford has continued to investigate the biochemical and genetic mechanisms behind immunosuppression in space. She writes that a series of experiments placed aboard the International Space Station showed that mice subject to weightlessness “demonstrated a reduction in expression of the same genes as seen in astronauts after landing.”
Hughes-Fulford concludes, “There is mounting evidence that gravity is required for normal function of bone and immune cells” – not surprising, she says, given that “all life developed in a gravity environment.”
The review ends by noting that 90 percent of NASA’s funding for science was cut in 2003, after the loss of the space shuttle Columbia, and has not been restored. One result, she writes, has been the “cessation of student and graduate training, thereby severing the pipeline for the next generation of scientists,” while recent funding cuts at the National Institutes of Health “further limit medical research and training of new investigators.” At stake, she says, is the future ability of “today’s visionaries” to create new jobs and technologies, thereby “securing our future prosperity.”
SFVAMC has the largest medical research program in the national VA system, with more than 200 research scientists, all of whom are faculty members at UCSF.
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