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Gemini 8 Target



The Gemini 8 Agena Target Vehicle (GATV-5003) was launched from Cape Canaveral using an Atlas-Agena D rocket on 16 March 1966 at 10:00:03 a.m. EST (15:00:03.127 UT) into a near circular 300 km orbit. The Gemini 8 spacecraft was launched 1 hour, 41 minutes later and accomplished rendezvous and docking with the GATV. However, attitude and maneuver thruster malfunction (on the Gemini 8 spacecraft) caused the docked spacecraft to tumble. Gemini 8 undocked from the GATV and the mission was terminated early. The GATV was used for further test manuevers following this, including eight orbital firings of the primary propulsion system and two firings of the secondary system. These left the GATV in a near-circular 380 km orbit. A total of 5439 commands were sent to the target vehicle and executed before electrical power was exhausted on the 10th day of orbit. The GATV was used as a passive target for a rendezvous by the Gemini 10 mission in July, 1966.

Gemini Agena Target Vehicle

The 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 GATV had a docking cone at the forward end into which the nose of the Gemini spacecraft could be inserted and held with docking latches. The GATV was a 7.93 meter long cylinder with a diameter of 1.52 meters, a dry mass of 1853 kg, and a fueled mass at orbital injection of 3228 kg. The forward section of the Agena airframe held the guidance, flight control electronics, telemetry, command, tracking, electrical power, and propellant pressurization equipment. The primary and secondary propulsion systems were at the aft end of the target vehicle with the attitude control gas tanks, and the main propellant (fuel and oxidizer) tanks were located in the mid-section. Propulsion was via a bi-propellant system, using unsymmetrical dimethylhydrazine (UDMH) and inhibited red fuming nitric acid (IRFNA). The Agena propulsion systems could be run while the Gemini was docked, allowing the GATV to be used to change the orbit of the docked pair. A minimum of five engine starts was possible. The docking cone was connected to the front end by shock absorbing dampers. Acquisition running lights and target vehicle status display indicators were situated on the front end. A 2.1 meter long retractable L-band boom antenna extended from the side of the cylinder near the front. Tracking and command of the GATV were also aided by a rendezvous beacon, two spiral L-band antennas, two tracking antennas (C-band and S-band), two VHF telemetry antennas, and a UHF command antenna. Micrometeoroid packages and other experiments could also be mounted on the GATV.

Gemini Program

The Gemini program was designed as a bridge between the Mercury and Apollo programs, primarily to test equipment and mission procedures in Earth orbit and to train astronauts and ground crews for future Apollo missions. The general objectives of the program included: long duration flights in excess of of the requirements of a lunar landing mission; rendezvous and docking of two vehicles in Earth orbit; the development of operational proficiency of both flight and ground crews; the conduct of experiments in space; extravehicular operations; active control of reentry flight path to achieve a precise landing point; and onboard orbital navigation. Each Gemini mission carried two astronauts into Earth orbit for periods ranging from 5 hours to 14 days. The program consisted of 10 crewed launches, 2 uncrewed launches, and 7 target vehicles, at a total cost of approximately 1,280 million dollars.

Alternate Names

  • 02104
  • Agena Target Vehicle 8
  • GATV-5003
  • Gemini8Target

Facts in Brief

Launch Date: 1966-03-16
Launch Vehicle: Atlas-Agena D
Launch Site: Cape Canaveral, United States
Mass: 1853 kg

Funding Agency

  • NASA-Office of Manned Space Flight (United States)


  • Engineering

Additional Information

Questions and comments about this spacecraft can be directed to: Dr. David R. Williams



NameRoleOriginal AffiliationE-mail
Dr. George E. MuellerProgram ManagerNASA
Dr. William C. SchneiderProject ManagerNASA Headquarters
Dr. Charles W. MathewsProject ManagerNASA Headquarters

Selected References

  • Gemini summary conference, NASA, SP-138, Wash, DC, Feb. 1967.
  • Grimwood, J. M., et al., Project Gemini technology and operations - A chronology, NASA, NASA SP-4002, Wash., DC, 1969.
Drawing of Gemini and the Gemini Agena Target Vehicle

Gemini and Gemini Agena Target Vehicle.

Gemini 8

Gemini Home Page

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