Project Horizon was a study to determine the feasibility of constructing a scientific / military base on the Moon. On June 8, 1959, a group at the Army Ballistic Missile Agency (ABMA) produced for the U.S. Department of the Army a report entitled Project Horizon, A U.S. Army Study for the Establishment of a Lunar Military Outpost. The project proposal states the requirements as:
"The lunar outpost is required to develop and protect potential United States interests on the moon; to develop techniques in moon-based surveillance of the earth and space, in communications relay, and in operations on the surface of the moon; to serve as a base for exploration of the moon, for further exploration into space and for military operations on the moon if required; and to support scientific investigations on the moon.
The permanent outpost was predicted to cost $6 billion and become operational in December 1966 with twelve soldiers.
A lunar landing-and-return vehicle would have shuttled up to 16 astronauts at a time to the base and back.
Horizon never progressed past the feasibility stage in an official capacity.
Rocket-vehicle energy requirements would have limited the location of the base to an area of 20 deg latitude/longitude on the Moon, from ~20° N, ~20° W to ~20° S, ~20° E. Within this area, the Project selected three particular sites:
- northern part of Sinus Aestuum, near the Eratosthenes crater
- southern part of Sinus Aestuum near Sinus Medii
- southwest coast of Mare Imbrium, just north of the Montes Apenninus mountains
- 1964: 40 Saturn launches.
- January 1965: Cargo delivery to the moon would begin.
- April 1965: The first manned landing by two men. The build-up and construction phase would continue without interruption until the outpost was ready.
- November 1966: Outpost manned by a task force of 12 men.
This program required a total of 61 Saturn I and 88 Saturn II launches up to November 1966. During this period the rockets would transport some 220 tonnes of useful cargo to the Moon
- December 1966 through 1967: First operational year of the lunar outpost, with a total of 64 launches scheduled. These would result in an additional 120 tons of useful cargo.
The base would be defended against Soviet overland attack by man-fired weapons:
- Unguided Davy Crockett rockets with low-yield nuclear warheads
- Conventional Claymore mines modified to puncture pressure suits
The basic building block for the outpost would be cylindrical metal tanks, 3.05 m in diameter and 6.10 m in length.
Two nuclear reactors would be located in pits to provide shielding and provide power for the operation of the preliminary quarters and for the equipment used in the construction of the permanent facility. Empty cargo and propellant containers would be assembled and used for storage of bulk supplies, weapons, and life essentials.
Two types of surface vehicles would be used, one for lifting, digging, and scraping, another for more extended distance trips needed for hauling, reconnaissance and rescue.
A lightweight parabolic antenna erected near the main quarters would provide communications with Earth. At the conclusion of the construction phase the original construction camp quarters would be converted to a bio-science and physics-science laboratory.
- Wernher von Braun (1959). Project Horizon Volume II: Technical Considerations and Plans. United States Army. p. 307.
- Project Horizon Report: Volume I, Summary and Supporting Considerations. United States Army. June 9, 1959.
- Project Horizon Report: Volume II, Technical Considerations & Plans. United States Army. June 9, 1959.