Project HARP, short for High Altitude Research Project, was a joint venture of the United States Department of Defense and Canada's Department of National Defence created with the goal of studying ballistics of re-entry vehicles and collecting upper atmospheric data for research. Unlike conventional space launching methods that rely on rockets, HARP instead used very large guns to fire projectiles into the atmosphere at extremely high speeds.

The Ballistic Research Laboratory (BRL) was a leading U.S. Army research establishment situated at Aberdeen Proving Ground, Maryland that specialized in ballistics as well as vulnerability and lethality analysis. BRL served as a major Army center for research and development in technologies related to weapon phenomena, armor, electronic devices, and high-speed computing. In 1992, BRL was disestablished and its mission, personnel, and facilities were incorporated into the newly created Army Research Laboratory (ARL).