International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / NASA and the Air Force are increasing the number of hypersonic and access-to-space programs creating a growing requirement for flight test ranges over large regional areas. A principal challenge facing these extended test ranges is the ability to provide continuous vehicle communications by filling the gaps in coverage between fixed ground stations. Consequently, there is a need for mobile range systems that provide a multitude of communication services under varying circumstances. This paper discusses the functional design and systems capabilities, as well as the mission support criteria, concerning NASA’s Mobile Operations Facility (MOF). The MOF will be deployed to Dugway Proving Grounds (DPG), Utah, in support of the X-33 single-stage-to-orbit (SSTO) demonstrator.