A community-developed continuation of the original RemoteTech mod for Kerbal Space Program.
RemoteTech allows you to construct vast relay networks of communication satellites and remotely-controlled unmanned vehicles. Your unmanned vessels require an uplink to a command station to be controlled. This adds a new layer of difficulty that compensates for the lack of live crew members.
A detailed manual is available online.
Questions? Try the KSP forum thread.
See the guidelines for both bug reports and pull requests.