The GATV (Gemini Agena Target Vehicle) was designed to be launched into Earth orbit prior to a Gemini mission and used for rendezvous and docking practice.

The Atlas-Agena was an American expendable launch system derived from the SM-65 Atlas missile. It was a member of the Atlas family of rockets, and was launched 109 times between 1960 and 1978.

The United States Air Force (USAF) is the air service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part of the United States Army Signal Corps, the USAF was established as a separate branch of the United States Armed Forces in 1947 with the enactment of the National Security Act of 1947.

• Gemini

  Human Spaceflight
  Project Gemini was NASA's second human spaceflight program. Conducted between projects Mercury and Apollo, Gemini started in 1961 and concluded in 1966.
  Program infoProgram wiki

• Agena Target Vehicle

  Space Tug
  Low Earth Orbit

  National Aeronautics and Space Administration