On July 20, 1969, history was made when two Apollo 11 astronauts, Neil Armstrong and Buzz Aldrin, became the first humans to set foot on the moon.

Years before, the U.S. Defense Department laid much of the groundwork that made the mission possible.

In 1946, the Army launched the WAC Corporal, which became the first U.S.-designed rocket to pass the edge of space going 69 miles above Earth - the edge of space is 62 miles from the Earth's surface. By 1949, the WAC Corporal attained an altitude of 250 miles - the same altitude as the International Space Station today.

Rocket research followed at the Army's Redstone Arsenal in Huntsville, Alabama. The Navy got into rocket research as well, producing the Viking rocket, which attained an altitude of 158 miles in 1954.

In early 1958, the U.S. Army and Navy both launched satellites into space.

Project Mercury was the first U.S. human spaceflight program. It lasted from 1958 to 1963. The rocket selected for the program's early suborbital flights was the Mercury-Redstone launch vehicle, developed in the early 1950s by the Army.

The U.S. Air Force wasn't idle. After NASA was created on July 29, 1958, the Air Force continued work on solid propulsion, booster systems, rockets and manned-orbital gliders that would be used for manned space missions.

For projects Mercury, Gemini and the early Apollo missions - NASA's first, second and third manned programs, respectively - the Air Force provided the launch facilities and vehicles at the Atlantic Missile Range, Cape Canaveral Air Force Station in Florida. It was renamed Cape Kennedy Air Force Station in 1963. A rocket sled track at Holloman Air Force Base in Alamogordo, New Mexico, was used for aerodynamic studies.

In 1961, the Army Corps of Engineers designed and constructed NASA facilities at what is now the John F. Kennedy Space Center in Florida, the location from which Apollo 11 would be launched.

The crew of Apollo 11 carried maps of the lunar surface on their mission to the moon in July 1969. The maps had been prepared by the Army Topographic Command specifically for their mission.

The Navy also took a direct role in Apollo 11, sending helicopters and divers from the aircraft carrier USS Hornet to recover the command module Columbia with the three astronauts aboard in the central Pacific Ocean on July 24, 1969.

One of the biggest contributions from the Defense Department was the astronauts themselves. Alan Shepard, the first American in space, was a Navy pilot. The first American to orbit the Earth, John Glenn, was a Marine. And, of the three Apollo 11 astronauts, Armstrong had served in the Navy and Aldrin and Michael Collins were both Air Force pilots. The overwhelming number of astronauts leading up to Apollo 11 were service members. There were not any Army astronauts until 1984.