Satellite repair is tricky business when you're dealing with extremely technologically advanced and expensive creations orbiting tens of thousands of kilometers above the earth, which is why DARPA is using a robotic servicing vehicle as part of a broader satellite servicing project.
The robotic service vehicle is the centerpiece of DARPA's Robotic Servicing of Geosynchronous Satellites project. The vehicle itself looks a lot like a satellite itself, although it is equipped with robotic arms and sockets that enable it to work with different kinds of tools and servicing kits. When deployed, the robotic service vehicle is capable of matching its orbit with that of the satellite it is supposed to be servicing, before collecting data and images that can be downloaded to Earth for assessment. The robot can then execute a servicing plan developed by mission control.
Considering that there are over 400 geosynchronous satellites out there, it's important to have a reliable way to be able to service and fix them, which is why the robotic servicing vehicle is set to have a huge impact in the space industry.