Rendezvous Docking Simulator
The Rendezvous Docking Simulator, also known as the Real-Time Dynamic Simulator, is a simulator at the Langley Research Center. It was constructed for the Gemini program in Building 1244 and it became operational in June 1963 at a cost of $320,000 and later reconfigured for the Apollo program.
Source: Wikipedia — Rendezvous Docking Simulator (CC BY-SA 4.0)