Teleoperator Retrieval System
The Teleoperator Retrieval System was an uncrewed space tug ordered by NASA in the late 1970s to re-boost Skylab using the Space Shuttle. == Description == TRS was a design for an uncrewed robotic space tug designed to be capable of remote payload observation and boosting or de-orbiting another spacecraft.
Source: Wikipedia — Teleoperator Retrieval System (CC BY-SA 4.0)