Cepollina concedes that at the time of the academy study, certain critical steps in robot servicing had not been demonstrated in space. But many of them have been since. The Defense Department/NASA Orbital Express mission, flown in 2007, showed that one satellite could dock with another automatically, use a robot arm to change the second satellite’s modular components, and transfer fuel. A low-cost Air Force satellite called XSS-11 was able to maneuver precisely around other spacecraft, and Dextre was installed on the space station in 2008.
“Orbital Express did all the things the academy said would be too difficult and risky,” says Cepollina. As a result of these projects, space robotics has convinced some former skeptics. “The technology has not advanced that much [since the academy study],” says Akin. “But the perception of it has changed tremendously.”
If the space station test goes well, Cepollina hopes to work out a deal to refuel several NASA and military satellites that are still in perfect working order except for lack of fuel. He envisions those missions jump-starting a commercial business to refuel and extend the lives of communications satellites that produce billions of dollars in revenue. “Once [refueling is demonstrated], the whole system could be turned over to commercial contractors,” says Cepollina.
Akin agrees, although he thinks that to be affordable, an operational system would probably have to use a smaller, lighter robot than Dextre. And, he says, “I give Cepi full props” for taking the lead in proving the feasibility of robotic servicing.
Cepollina seems worried only by the prospect of competition. A Swedish company, Orbital Satellite Services, is developing a spacecraft tug, based on the European SMART-1 moon probe, to extend the lives of commercial communications satellites by serving as a new propulsion system. It’s a simpler and likely cheaper alternative to refueling, with no capability (at least initially) to handle more complicated repairs. Dennis Wingo, a principal in Orbital Satellite Services who has been working on plans for commercial satellite servicing for years, says the company already has one “hard, signed contract,” although it has yet to nail down the financing it needs for a refueling mission.
But Cepollina has decades of experience, a dedicated team, and now, approval and funding for a test on the space station. If this turns into a race, you might not want to bet against him.
Robert Zimmerman’s latest book is The Universe in a Mirror: The Saga of the Hubble Space Telescope and the Visionaries Who Built It (Princeton, 2008).