The World’s Highest Laboratory

The space station’s finished. Now what?

On the space station, U.S. astronauts will soon conduct experiments, selected by a new space science center, aimed at making life better on Earth. (NASA)
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In the third lab, the Japanese-built Kibo, experiments are focused on space medicine, biology, Earth observations, materials production, biotechnology, and communications research. The Japanese space agency, JAXA, has selected 19 candidate experi­ments to fly in 2012—15 in life sciences and four in materials sciences. Some of the more exotic involve studying the effects of microgravity on zebrafish, mouse embryos, and mammalian reproductive cells.

EVIDENCE IS MOUNTING that the odd behavior of cells and microbes in space might lead to shortcuts in fields as diverse as disease pathology and crop development. Because this is one area where research in microgravity might translate into useful science on Earth, biological experiments will be a key focus of the National Laboratory. Experiments on both the shuttle and the station have shown that microgravity alters gene expression in microbes and plant and animal cells, and researchers want to continue to use the station to gain insights into these changes.

Much of NASA’s optimism for the National Laboratory springs from an unusual 2006 experiment initiated by microbiologist Cheryl Nickerson of Arizona State University’s Biodesign Institute and NASA’s Mark Ott, a microbiologist at the Johnson Space Center in Houston. Ott had noted that astronauts’ immune systems appeared to weaken during spaceflight, “and I asked him whether we knew anything about the effects of spaceflight on microbial pathogens,” Nickerson recalls. “He said ‘Not really.’ ” It was not a farfetched question. Biologists have long known that microbes have an uncanny ability to thrive in extreme environments, such as ocean floor vents, cave ponds, or toxic waste dumps. Why not in space?

So Nickerson and Ott decided to fly cultures of salmonella bacteria aboard space shuttle Atlantis to see what happened. The cultures were placed in individual chambers that the shuttle crew activated for 24 hours. Back on Earth, the team tested the samples and found that, in space, several key salmonella genes manifested themselves differently, and that a particular protein acted as a master switch to turn up the infectivity of the bacteria. The group validated the work on another shuttle mission, showing that they could turn off the infectivity by manipulating salts in the cultures.

Similar research was done by Astrogenetix, a company in Austin, Texas, which knocked out several salmonella genes and flew those cultures in worms on the shuttle. In doing so, they took away the bacteria’s infective power. The company plans to submit its findings to the Food and Drug Administration to get the altered bacteria approved as an investigational new drug, with the goal of creating a vaccine.

NIH, a longtime NASA collaborator, is interested in this biomedical research and has begun a grant program seeking applications from a broad range of disciplines. “The idea is to increase the use of the space station for research that applies to a much broader purpose—human health,” says Joan McGowan, director of NIH’s division of musculoskeletal diseases, who is overseeing the competition.

Arizona State’s Nickerson, for one, is an applicant, and already has an agreement with NASA to test salmonella in space as a carrier for a pneumonia vaccine that is under development. “Gravity may mask changes in gene expression that regulate a live vaccine,” she says. “Our hypothesis is that spaceflight will make our vaccine stronger. We want to observe these changes in space, then tweak the vaccine to get a better strain.”

Another project, directed by Harvard Medical School assistant professor Paola Divieti Pajevic, one of the first NIH grantees, will grow bone cells in space to find genes that sense gravity and regulate bone mass. “By either stimulating genes or blocking genes, we can perhaps prevent bone loss or stimulate bone growth in patients on the ground,” she says. “The ISS would be the proof of principle that our lab model is working.”

Under the terms of the NIH program, Divieti Pajevic has two years to prepare the experiment before flying it. NIH and NASA have asked the team to design the project so it keeps astronaut time to a minimum, and to make sure there is a way to provide electricity to the payload during launch and docking. Another limitation, she notes, is that “you only get one shot.” If the experiment does not work immediately, there’s no tweaking for second chances.

MANY IN THE AEROSPACE community are generally upbeat about the station’s possibilities, noting that it already has weathered hard times. Station research suffered a blow during the George W. Bush administration, when the budget for human spaceflight was focused on a return to the moon and eventually a manned flight to Mars. Station science was further hurt in the aftermath of the 2003 Columbia disaster, when the shuttles were grounded for more than three years. “Life science was cut by 90 percent,” says former astronaut Jeffrey Hoffman, a professor of aerospace engineering at MIT. “Engineering technology research budgets were decimated.”

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