SPHERES remote control demonstration bodes well for future space exploration
Controlling a robot in space from the ground can be a bit like hitting a moving target. There’s a one to three second delay as data passes back and forth between the robot and ground control, which means that operators have to anticipate how the robots will move during these delays. This week, the Lockheed Martin Advanced Technology Center (ATC) announced the first-ever demonstration of collaborative tele-operations that involved control of robots on the International Space Station (ISS) by astronauts on the ISS and operators on the ground.
Given how counterintuitive weightlessness is, remote operation of robots in space poses major problems; especially when delicate equipment and exhaust gases from other satellites are involved. One way of handling the delay as instructions travel between space and the ground via satellite relays is by building systems with a high degree of autonomy. But, according to Lockheed, what NASA and the ATC were demonstrating on the ISS is a slightly different approach, where the ground controller is working in concert with a second operator on the space station using an interface that allows for automated control of one or more robots combined with manual control.
The Synchronized Position Hold, Engage, Re-orient, Experimental Satellites (SPHERES) robots used in the demonstration are designed as free-flying technology test beds and operating them poses challenges very similar to those of maneuvering unmanned satellites for docking or maintenance operations. The three soccer ball-sized SPHERES need to be able to orientate themselves in space, to move in three dimensions, to track one another in flight, and to maintain station in relation to one another – all of which are important for future satellite operations.
In the recent tests, Astronaut Karen Nyberg on the ISS and ATC engineer Humberto Ormeno back on Earth carried out coordinated control of the SPHERES robots using an ATC-developed, 3-D user interface that promises to open up new capabilities not only for missions in Earth orbit, but also further afield on missions to the Moon or Mars. The robots were commanded in “follow-the-leader” exercises where two of the robots followed a lead robot that was under operator control, along with simulated approach-and-docking maneuvers, like those required for in-space assembly of large space structures and asteroid exploration. Lockheed says the system is also highly flexible, with one or more robots operating under automated control able to be combined with manual control of another.
"Supervising a team of robots in microgravity requires intuitive and informative user interfaces so operators can maintain control over sensitive maneuvers without being overwhelmed by details,” says Andrew Zimdars, who leads the ATC effort. "SPHERES enables us to work with the astronauts who will command future exploration missions and develop software technologies that meet their needs."
Source: Lockheed Martin