Science In Orbit

Very few research facilities exist where a broken toilet is as likely to make international news as a scientific breakthrough. But the International Space Station—or ISS as it’s known in the acronym-rich world of NASA, the National Aeronautics & Space Administration—is no ordinary research center. Flying 200 miles above Earth, the space station’s environment of microgravity makes unique scientific research possible and plumbing problems a major issue.

More than a decade after its construction began, ISS is nearly finished—at a cost of $48.5 billion. As the final pieces are bolted into place and crew members can begin shifting their focus from construction to conducting experiments, research on the space station faces an uncertain future. Scarce research funding, limited crew time for research, and few opportunities to actually fly new experiments onto the station all threaten to keep the unique research facility from achieving its potential.

In December, the Government Accountability Office released a report (GAO-10-9) that identified four major challenges for ISS (C&EN, Jan. 4, page 18). First, GAO noted that when NASA retires the space shuttles this year, opportunities to transport research cargo to and from the space station will be extremely limited.

A space shuttle can carry almost 
38,000 lb to and from ISS, but the existing vehicles that NASA will rely on once the shuttles are retired—from space agencies in Russia, Japan, and Europe—have far less so-called upmass capability and virtually no downmass capability. So getting experiments up to the space station will be difficult, but getting them back down for analysis will be nearly impossible. Other vehicles from commercial space flight companies are in the works, but their ability to get to and from ISS hasn’t been demonstrated yet.

Paying for experiments is also a major source of concern, GAO says. NASA estimates that it costs $44,000 per kg to launch an ISS experiment, and other agencies told GAO costs were much higher. The Department of Agriculture, for example, said its average payload cost was $250,000 for an experiment that fit in a compartment the size of a shoe box. Without dedicated funding for ISS, it’s unclear how such costly experiments will be financed.

Although the ISS crew expanded from three to six last March, GAO worries that the fixed crew size and the many demands on crew members’ time pose “a significant constraint for science on board the ISS.”

Finally, GAO cites ISS’s uncertain future as a major obstacle in attracting scientists to do research on the station. ISS is currently scheduled to be retired in 2015, which puts quite a crimp on any long-term scientific projects. The Review of Human Space Flight Plans Committee, a blue-ribbon panel established by President Barack Obama to assess NASA’s plans for human exploration, has proposed extending ISS’s mission until 2020. And Congress has requested that NASA ensure the station can stay viable until that time. Still, no commitment has been made to ISS beyond 2015, although that could change when Obama announces ISS’s fate—likely sometime this week.

“I am convinced that stopping the station in 2015 would be a mistake because we cannot attract the best scientists if we are telling them today, ‘You are welcome on the space station but you’d better be quick because in 2015 we close the shop,’ ” said Jean-Jacques Dordain, director general of the European Space Agency, at a press conference last month.

Scientific research on ISS was originally planned to encompass a wide range of disciplines in the physical and biological sciences. In 2004, however, NASA reoriented ISS’s research priorities following then-president George W. Bush’s plan to send Americans back to the moon by 2020 and to Mars after that. With this new mission, NASA chose to focus ISS research on the effects of prolonged time in space on humans and on the technology needed for such long-duration space operations.

Consequently, many space station research projects in the basic physical sciences fell by the wayside. However, Congress designated ISS a national lab in 2005, making about half of the station’s space and crew time available to organizations other than NASA. The idea was that other agencies and private-sector organizations would make use of the station for experiments that no longer fit with NASA’s mission.

John A. Pojman Sr., a chemistry professor at Louisiana State University, says he has yet to see such opportunities arise for his area of research, the behavior of miscible fluids in microgravity. Pojman had two projects scheduled for ISS that were canceled when NASA refocused its research priorities.

He was able to conduct some experiments in 2004 and 2005 when NASA called for projects that could be done with materials already on board ISS. Using water, Russian honey, and some urine collection syringes, Pojman had the astronauts mix the miscible fluids and film their behavior.

“You’re really dependent on which astronaut is doing the experiment and how much time they want to spend on it,” Pojman says. The trouble, he explains, is that the crew has very limited time.

Automated experiments aren’t necessarily any easier, Pojman says. Doing an automated experiment on the space station is like doing an automated experiment on a school bus full of kindergartners, he explains. “The children won’t be able to help you, but they’re going to be a safety risk.”

One highly successful ISS project where automation is going to become far more important once the space shuttles are retired is the Materials International Space Station Experiment (MISSE). In MISSE, a suitcaselike metal container holds hundreds of mounted samples of different materials. The suitcase is attached to the outside of ISS so that these materials, which include everything from solar panels to space suit fabrics, are exposed to the ravages of space.

“These are experiments that can only be done in space,” says Kim de Groh, a senior materials research engineer at NASA’s Glenn Research Center. “Ground test facilities do not simulate exactly the combined atomic oxygen, temperature cycling, and radiation conditions of space,” she says. Data from MISSE have been important, for example, in helping aerospace companies decide what materials to use when building satellites, de Groh notes.

Robert Walters, head of solid-state devices at the Naval Research Laboratory and a principal investigator on MISSE, says MISSE projects are moving from so-called passive experiments, where materials come back to Earth for analysis, to active experiments, where the analytical instrumentation is built into the experiment and data are sent back to Earth in real time.

MISSE-7 is currently aboard ISS and MISSE-8 is scheduled to go up this summer. But the big question, Walters says, is with the shuttles retiring, how are we going to get MISSE-8 back home? The current plan is to send it back on Dragon, a vehicle that’s being developed by the commercial space flight corporation SpaceX. “It’s very risky for me because it’s an unproven vehicle,” Walters says.

Although MISSE has been tremendously successful, Walters notes that it’s pretty low maintenance for the ISS crew. Aside from hooking it on and off the station, there’s nothing for the astronauts to do. That’s not the case for many of the other science experiments on board ISS.

“It’s hard to do world-class science when you don’t have world-class scientists up there doing it,” says Albert Sacco Jr., a chemical engineering professor at Northeastern University. Sacco grew zeolite crystals aboard ISS in 2001 and 2002 and found that the microgravity environment created larger crystals and can be used to modify the number and location of lattice site defects. He wishes that NASA would bring more scientists on board ISS. The primary goal of the crew that’s up there now is to operate the space station, he says.

Sacco also says he had a tremendous advantage in designing his ISS experiment—he was in the astronaut corps and flew on the space shuttle Columbia in 1995. “The skill set for space is actually quite different from the skill set you’d use on the ground,” he says. “It takes years to learn how to utilize the environment so you do the right experiment and you do it correctly.”

“Right now we can’t do the kind of science that we’d call cutting edge,” he points out, because the science is done at a distance. Everything must be done by computer, and it takes years to get a new experiment on board.

Lawrence J. DeLucas, director of the University of Alabama, Birmingham’s Center for Biophysical Sciences & Engineering, was one of many investigators who crystallized proteins on ISS in 2001 and 2002. DeLucas and his colleagues found that in microgravity, they were able to grow crystals far superior to what they saw on the ground.

“It’s sad that this program has been done away with,” DeLucas says. “Instead of putting up 10 samples like we did back then, we now have hardware that will hold 1,000 samples.”

He agrees with Sacco that it was frustrating to get results from an experiment and then not be able to send another up for a year or more. “You need constant access to the space station environment,” DeLucas says. If you were able to send samples up every three months, he notes, “you could see a lot of projects turn the corner.”

“We spent a lot of money on the space station, and we should be doing science on it,” DeLucas says. “We’re not doing enough of it. It’s just a shame.”

Such complaints are familiar to Julie Robinson, an ISS program scientist, although she says that they’re uncommon among scientists currently working on ISS. What’s important to keep in mind, she says, is that NASA and the ISS international partners are only now just completing construction on the station. “We have not yet seen the depths of what scientists looking at their particular discipline can accomplish,” she adds.

Robinson notes that in the past three months, modules for combustion and fluid experiments have been installed on ISS, and a confocal microscope and microgravity glove box are also in place. “We now have really amazing infrastructure for doing physical science research,” she says.

But Robinson also acknowledges that the challenges highlighted by GAO are legitimate. “The most important of those challenges is having the funding available,” she says. “Scientists live or die by the funding they get.”

Robinson also notes that if ISS is retired in 2015, it’s unlikely to reach its full potential. “The challenge is in having the time to get the results and to do any follow-on investigations that need to be done to move a discipline forward,” she says. “We need more than just five years to do that. We’ve never had this opportunity in space before, and we probably won’t again for a very long time.”