purposes, and the United States Apollo program to send men to the Moon chose a mission mode that would not need in-orbit assembly. A smaller station that a single rocket could launch retained value, however, for scientific purposes. Early studies In 1959, von Braun, head of the Development Operations Division at the Army Ballistic Missile Agency, submitted his final Project Horizon plans to the U.S. Army. The overall goal of Horizon was to place men on the Moon, a mission that would soon be taken over by the rapidly forming NASA. Although concentrating on the Moon missions, von Braun also detailed an orbiting laboratory built out of a Horizon upper stage, an idea used for Skylab. A number of NASA centers studied various space station designs in the early 1960s. Studies generally looked at platforms launched by the Saturn V, followed up by crews launched on Saturn IB using an Apollo command and service module, or a Gemini capsule on a Titan II-C, the latter being much less expensive in the case where cargo was not needed. Proposals ranged from an Apollo-based station with two to three men, or a small "canister" for four men with Gemini capsules resupplying it, to a large, rotating station with 24 men and an operating lifetime of about five years. A proposal to study the use of a Saturn S-IVB as a crewed space laboratory was documented in 1962 by the Douglas Aircraft Company. Air Force plans The Department of Defense (DoD) and NASA cooperated closely in many areas of space. In September 1963, NASA and the DoD agreed to cooperate in building a space station. The DoD wanted its own crewed facility, however, and in December 1963 it announced Manned Orbital Laboratory (MOL), a small space station primarily intended for photo reconnaissance using large telescopes directed by a two-person crew. The station was the same diameter as a Titan II upper stage, and would be launched with the crew riding atop in a modified Gemini capsule with a hatch cut into the heat shield on the bottom of the capsule. MOL competed for funding with a NASA station for the next five years and politicians and other officials often suggested that NASA participate in MOL or use the DoD design. The military project led to changes to the NASA plans so that they would resemble MOL less. Development Apollo Applications Program NASA management