International Telemetering Conference Proceedings / November 04-07, 1991 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The Gulf Range Drone Control Upgrade System (GRDCUS) Mobile Control System (GMCS) is an integral part of the test ranges located on the Gulf of Mexico. This paper begins with a brief overview of the current Gulf Range systems. These systems consist of five major components: ground stations, ground computer systems, data link/transponders, consoles, and software. The GMCS van contains many of these components to provide a stand-alone range capability for remote operations. This paper describes the development and assembly of the GMCS van and focuses on the on-board computer systems, consoles, and data link technology. An overall system engineering approach was used during GMCS development and is highlighted through the use of rapid prototyping. This methodology and the lessons learned are presented in the paper. Suggestions for future applications are considered.