See gallery: “The ascent of space stations from Salyut to the ISS“
A PREMIER, world-class laboratory in low Earth orbit. That was how NASA sold the International Space Station to US congress in 2001. Eleven years on and no one can doubt the agency’s technological ambition. The most complex engineering project ever attempted has created a behemoth of modules that orbits the planet at more than 27,000 kilometres per hour.
It might be travelling fast but, scoff critics, as a lab it is going nowhere. So far, this money-eating monster has gobbled up $150 billion – more than $300,000 for each kilogram in orbit – and even fans admit that it has yet to fulfil its potential for scientific discovery. “The ISS is the greatest laboratory ever assembled,” says Laurence Young, a space medicine expert at the Massachusetts Institute of Technology. “It is also a pale shadow of what it could be.”
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Yet the station’s fortunes could be about to change. With the US portion completed in 2011, the ISS has now been resupplied by the SpaceX Dragon capsule, ushering in an age of private, cheaper rocketry. And NASA has just charged a new agency to kick-start the station’s research programme. But where should its future priorities be directed? And what will it take to transform this orbiting construction site into a world-class lab?
Some of these questions were addressed at the in Denver, Colorado, last month. Among the presenters was Satoshi Iwase of Aichi Medical University in Japan. He has spent several years developing an experiment that could help solve one of the key problems that humans will face if we are to travel to other planets: keeping our bodies healthy in weightlessness.
One thing that physiologists have learned from putting people in space is that without gravity our bodies begin to weaken. Even the routine of treadmill running, weightlifting and cycling that the ISS crew follows leaves them with weakened bones, muscles and cardiovascular systems. To counter these effects on a long-duration mission to, say, Mars, astronauts will almost certainly need to create their own artificial gravity.
This is where Iwase comes in. He leads a team designing a . In their preliminary design, an astronaut is strapped into the seat of a machine that resembles an exercise bike. Pedalling provides a workout for the astronaut’s muscles and cardiovascular system, but it also rotates the seat vertically around a central axis so the rider experiences artificial gravity while exercising. “The centrifuge spins the astronaut up and over,” says William Paloski at the University of Houston in Texas, who is working on the design.
The centrifuge project highlights the station’s potential as a research lab. Similar machines have flown in space aboard NASA’s shuttles, but they couldn’t be tested for long enough to prove whether they were effective. Paloski calculates that to properly assess a , astronauts would have to ride it for 30 minutes a day for at least two months. “The only way to test this is in weightlessness, and the only time we have to do that is on the space station,” Young says.
The ISS offers more than just a stable lab bench for long-term experiments, however. With about 4000 square metres of photovoltaic panels, the station has a beefy electrical supply on tap for power-hungry experiments. High-speed data links to Earth and a crew of lab technicians who can modify apparatus or download results add to the attraction. Combine this with a gravity field a million times weaker than that on Earth’s surface, and the station ought to be a space researcher’s dream come true.
The reality is rather different. There are certainly plenty of ideas for experiments: scientists would like to understand how microgravity affects everything from plant growth to the human immune system. Some important experiments including the Alpha Magnetic Spectrometer – a particle detector searching for signs of dark matter – are already aboard and gathering data. But many other cherished projects have yet to fly, despite about a quarter of the station’s dedicated lab space remaining empty. Tight budgets, lack of time or vision, and a maddening bureaucracy are all to blame – a source of constant irritation to NASA staff, researchers and human space-flight fans alike.
Iwase and his team have experienced these frustrations at first hand: their centrifuge project is currently on hold. Engineers at NASA and the European Space Agency are concerned that vibrations from the seat’s rotation will interfere with the links between ISS modules. Iwase’s team are looking for ways around this, and ESA, which is funding the centrifuge, together with the Japanese Space Agency, will decide later this year whether the fixes are worth the cost. Yet even if it gets the green light, the station’s crew will still have to wait until 2017 before they can take a spin.
Lengthy delays like this are one of the key challenges for NASA, according to . Its authors said they were “deeply concerned” about the state of NASA’s science research, and made a number of recommendations. Besides suggesting that the agency reduces the time between approving experiments and sending them into space, it also recommended setting clearer research priorities and providing better resources to support these plans.
NASA had already begun to take action. In May 2010, the agency hired to develop a plan for how to cut through the ISS’s infamous bureaucracy. “It’s hard to imagine an extraordinary human endeavour such as the ISS not having really brilliant management,” says Jeanne DiFrancesco, from ProOrbis in Malvern, Pennsylvania.
Congress also directed NASA to hire an independent organisation to help manage the station’s US lab facilities. In July 2011, the agency chose the not-for-profit . Under the $15 million annual contract, CASIS is to reshape the way research on the ISS is managed, find a balance of experiments with broad and practical goals, and convince public and private investors that science on the station is worth the spend.
It faces an uphill struggle. Critics have long rounded on the station’s record for science. Judged solely by the number of papers published, the ISS certainly seems poor value: according to Christopher King, an analyst at Thomson Reuters’s Web of Science database, research on the station has generated about 3,100 papers since 1998. The Hubble Space Telescope, meanwhile, has produced more than in its 21 years, yet it cost less than one-tenth of the price of the space station. Even the $150 million Wilkinson Microwave Anisotropy Probe, designed to measure the cosmic microwave background, has generated 5,100 papers in just over a decade.
Yet Mark Uhran, assistant associate administrator for the ISS, bristles at critics who say that the station hasn’t done any . He points to progress made on a salmonella vaccine and the growth of protein crystals in microgravity. Besides, he argues, it is unreasonable to judge the value of discoveries from the past decade, when the station was still being assembled. “No one asked the scientists at the Large Hadron Collider what discoveries they made while they were building it.”
“No one asked scientists at the LHC what discoveries they made while they were building it”
To get the ISS’s research back on track, CASIS has examined more than 100 previous microgravity experiments to identify promising research themes. From this, it has decided to focus on life science and medical research, and recently called for proposals for experiments on osteoporosis, muscle wasting, the immune system and . The organisation also believes that the ISS should be used to develop products with commercial application and to test those that are either close to or already on the market. Investment from outside organisations is vital, says Uhran, and a balance between academic and commercial research will help attract this. A number of aerospace companies and academic institutions are already interested in using the station, the centre says, but their identities are confidential at present.
Plans for commercial activity have not gone smoothly, however. On 29 February, CASIS’s executive director, Jeanne Becker, saying that she has faced pressure to engage in activity that would jeopardise the centre’s non-profit status. She also stated that asking ProOrbis to stay on in an advisory role to the organisation felt like a conflict of interest. At the same time, there have been for the US Government Accountability Office to audit the centre.
However these issues are resolved, a fundamental barrier remains to developing science in microgravity. The station needs to attract cutting-edge research, yet many scientists seem to have little idea what goes on aboard it. As part of her assessment, DiFrancesco conducted more than 200 interviews with people from organisations with potential interests in low gravity research. Some were aware of the ISS but they didn’t know what’s going on up there, she says. “Others know there’s science, but they don’t know what kind.”
CASIS hopes its efforts will help the station turn a corner. And according to Alan Stern, planetary scientist and senior science adviser at the centre, the biggest public-relations boost for the ISS may come from an unexpected quarter: the privately funded space flight industry.
That’s not the primary aim of commercial space flight, of course. Even so, companies like SpaceX and Orbital Sciences should help NASA and its partners save money on resupplying the ISS. SpaceX, for example, suggests it can , to about $55 million a launch. Sub-orbital craft like Virgin Galactic’s SpaceShipTwo or Zero2Infinity’s high-altitude balloon could also boost the space station’s fortunes. They might not come close to the ISS’s orbit, yet Stern believes they will revolutionise the way we perceive space. Soon everyone will be dreaming of interplanetary travel again, he predicts.
More importantly, scientists are already queuing for seats on these services. The Southwest Research Institute in San Antonio, Texas, has reserved $1.6 million worth of tickets for rides on SpaceShipTwo and XCOR Aerospace’s craft so that its scientists can collect data during a few minutes of weightlessness. This demand for low-cost space flight could eventually lead to a regular service, giving researchers the chance to test their ideas before they submit a proposal for experiments on the ISS. Getting flight experience should help win a slot on the station, says Stern. “We’re not used to thinking of low-entry space flight. The impact will be huge.”
If the station’s managers can exploit this enthusiasm for space flight as well as learn from past mistakes, their newly completed lab has every chance of fulfilling its potential. And here’s a thought to help keep them focused: there are plenty of other expensive research facilities yet the ISS is probably the only one that can be by billions of taxpayers. As it flies overhead each night, this lab is set to remain firmly in the public eye – a twinkling reminder of NASA’s promise.
Rock and roll
The International Space Station might be prime research real estate (see main story), but it also faces some unique problems. The lack of gravity makes simple experiments that bit harder, says Leroy Chiao, a former NASA astronaut who spent 6 months aboard the ISS. “If you let go of something or even if you secure it down and someone bumps it, it can go floating off. Sometimes you’ll find it in the air filter or it can get lost for days or months, or perhaps you never find it.” In addition, crew movements, the hum of fans and pumps, and the drag of the station through space all generate minute vibrations. Although weak, these can be enough to disturb crucial experiments such as those growing delicate protein crystals, says Chiao.
So a team at the Russian space agency Roscosmos have proposed a solution. is a 7-tonne autonomous lab designed to fly separately but in formation with the ISS. It will be able to dock with the station when needed to allow the ISS crew to carry out maintenance and set up equipment. This semi-detached approach should allow sensitive experiments on the free-flying lab to remain vibration free. OKA-T is scheduled to launch in (see diagram).FIG-mg28731901.jpg
Another challenge for experiments on the ISS is chemical contamination. Each time thrusters on the ISS fire, they release small amounts of propellant into space. The result is that for more than a decade, chemicals including hydrazine have been accumulating on the outside of the ISS and in the space around it. This coats solar panels and externally mounted instruments, and astronauts bring it back into the station after each spacewalk.
A new thruster system may help reduce contamination. Engineers at aerospace company Firestar Technologies are investigating a system based on nitrous oxide, a cheap, non-toxic propellant.Their is set to be tested on the ISS next year. The plan is to on SpaceX’s Dragon capsule, then attach it to the outside of the station with a robot arm. After that, it will be used instead of conventional thrusters to help keep the ISS in position.
