The Front-end Robotics Enabling Near-term Demonstration (FREND, a play on friend) is a DARPA project "aiming to create a fully autonomous docking capability for satellites that weren't built to be serviced", currently under testing at the U.S. Naval Research Laboratory Spacecraft Engineering Department.[1]
The FREND mission concept uses robotic arms to position a grappling tool at a customer spacecraft structural hardpoint, and docks the two spacecraft together by first rigidizing this tool, then rigidizing the positioning robotics.[2] FREND has been described as a robotic manipulator technology "that someday could potentially deliver fuel, provide repairs, or reposition satellites."[3]