Robotic satellite servicer rehearsal underway in orbit

The concept of dispatching low-cost spacecraft to repair and refuel more expensive troubled satellites took a step closer to reality Sunday when two first-of-a-kind orbiting testbeds began operations to validate autonomous in-space servicing techniques. The two craft are part of the U.S. government's $300 million Orbital Express program, which is sponsored by the Defense Advanced Research Projects Agency, the Pentagon's primary research and development arm. More

(Source: SPACEFLIGHT NOW - Apr 4)