Here is a scenario that might keep International Space Station managers up at night. A pharmaceutical researcher in Birmingham, Ala., needs some ISS crew time to extract and prepare some large protein crystals grown in microgravity for a return to Earth on a Dragon capsule. The capsule is filling up, and the crew is busy loading it with valuable “downmass” that is eagerly awaited on the ground. Among the other space-generated samples ready to go are some coupons of advanced composite material that belong to a sporting goods company in Carlsbad, Calif. The company needs the composites to open a new production line in its golf club factory. But the protein crystals may contain the key to developing a new molecule that inhibits the progression of Parkinson's Disease. There's only time and space for one more payload in the Earth-return capsule, so who sets the priority and how do they decide?
The question isn't as far-fetched as it might seem. Larry DeLucas, a researcher at the University of Alabama in Birmingham who flew protein-crystal growth experiments as a payload specialist on the STS-50 space shuttle mission aboard Columbia in June 1992, is already preparing to grow more protein crystals on the ISS. And the Center for the Advancement of Science In Space (Casis), which runs the U.S. National Laboratory portion of the station, has just signed an agreement with Cobra Puma Golf to conduct materials research on the ISS.
Right now, there should be enough space and crew time to accommodate both research projects, and many more (AW&ST June 25, p. 38).
But in anticipation of more demand on station resources,is already angling for a fourth U.S.-side crew member and planning upgrades to improve research efficiency (see p. 50). Questions of priority are sure to arise, and it isn't necessarily clear how and its partners will resolve them.
DeLucas is eagerly awaiting long-term access to microgravity for his experiments, in the well-informed belief that it will produce large enough protein crystals for the high-resolution X-ray crystallography he needs to pinpoint molecular inhibitors for diseases like Parkinson's and cystic fibrosis. And Casis, a non-profit struggling to get started on its mandate to bring private capital and commercial research together on the ISS, is building a “space is in it” marketing scheme around products like the high-tech golf clubs Cobra Puma Golf produces in Carlsbad.
Some products may even be drugs produced using protein crystals. The first Casis request for proposals, issued last month, seeks ideas for “advancing protein crystallization using microgravity.” Will NASA and Casis set priorities based on commercial potential, and if they do, will golf clubs outscore life-saving drugs? It may not come to that, because research already underway on the space station is demonstrating that teleoperated robots in space can stretch crew time significantly.
Joint U.S./Canadian tests are demonstrating that the state-of-the-art in space-based robotics is up to the job of servicing a variety of satellites in orbit. Not only does that raise the possibility that expensive spacecraft can be refueled and repaired to extend their service lives for commercial, scientific and military purposes. It also shows how researchers on the ground can manipulate their own experiments on the orbiting lab, without much help from the flight crew.
Using the Canadian-built ISS robotic arm and special-purpose dexterous manipulator dubbed Dextre, controllers in Houston and St. Hubert, Canada, have started work with a NASA-developed testbed and toolkit to validate satellite-servicing techniques. Early tasks on the Robotic Refueling Mission (RRM) have gone well, according to Jill McGuire of NASA's, the RRM project manager, paving the way for an end-to-end refueling test in late August or early September. That, in turn, will set up more difficult tests by the end of the year, McGuire says.
So far controllers have used the RRM tools to cut wires, remove caps and pull plugs. The testbed is equipped with four tools, two of them able to handle different types of hardware, and a series of task plates designed to test their ability to perform delicate tasks like removing standard No. 10 fasteners and capturing small parts, lest they become space debris. The mission also has collected images of a variety of satellite fittings and other hardware on the testbed under different lighting conditions to generate a machine-vision database for future servicing applications (photo). Ultimately, the two space agencies hope to build a free-flying satellite servicer using the vision and other data collected with the space station tests.
“We're able to buy down this risk by using the International Space Station,” McGuire says. In addition to increasing ISS crew efficiency, the work could spur a potentially lucrative satellite-servicing industry (AW&ST March 21, 2011, p. 23), easing the pressure to set priorities.