{| |} The Martin Marietta Model 845 was a remotely-piloted aircraft developed in the United States in the late 1960s and early 1970s for use as a communications relay in the Vietnam War. Two prototypes were built as part of the United States Air Force's Compass Dwell program, these machines also being based on a Schweizer SGS 1-34 sailplane and similar in configuration to the competing XQM-93 design by Ling-Temco-Vought. Test flights were performed in 1971, with one of the prototypes staying aloft for almost 28 hours, but the Model 845A was cancelled along with the XQM-93.