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Gemini 6 Target

NSSDCA ID: GEM6T

Description

The Gemini 6 Agena Target Vehicle (vehicle GATV 5002) was launched from Cape Canaveral on 25 October 1965 at 10:00:04 a.m. EST (15:00:04 UT) on an Atlas-Agena D rocket. At 10:05:10 a.m., 5:06 after launch, the Agena separated from the Atlas successfully and all signals were normal, but 368.4 seconds after launch, at initiation of Agena target vehicle primary propulsion system firing for Earth orbit insertion, an anomaly occurred and telemetry and radar beacon track were lost 7 seconds later. All attempts to reestablish contact or radar track with the vehicle failed. Just before loss of contact telemetry showed a marked rise in pressure in both propellant tanks. Shortly afterwards radar at Patrick AFB reportedly "picked up 5 pieces" of debris at the point in space the Agena was supposed to be. The Gemini 6 launch, scheduled to occur 101 minutes later, was cancelled. Later investigation concluded the most likely cause of the failure was a hard start and explosion caused by fuel preceding oxidizer into the thrust chamber during ignition.

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 and a dry mass of 1834 kg. At launch it carried 6375 kg of propellant and gas. 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

  • GATV-5002

Facts in Brief

Launch Date: 1965-10-25
Launch Vehicle: Atlas-Agena D
Launch Site: Cape Canaveral, United States
Mass: 3261.0 kg

Funding Agency

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

Discipline

  • Engineering

Additional Information

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

 

Personnel

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

Selected References

Gemini midprogram conference including experimental results, NASA, SP-121, 1966. (Papers Presented at the Manned Spaceflight Center, Houston, Feb. 23-25, 1966)

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.

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