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Gemini 9 Target B



The Gemini 9 Augmented Target Docking Adapter (ATDA) was launched from Cape Canaveral using an Atlas-Agena D rocket at 10:00:02 a.m. EST (15:00:02.363 UT) on 1 June 1966. The spacecraft was successfully injected into a near-circular 304 km orbit, but telemetry signals indicated that the launch shroud, which covered the docking adaptor, had separated but had not been jettisoned. This was confirmed when Gemini 9 was launched two days later and the astronauts observed the launch shroud still on the ATDA blocking the docking port, looking, according to Tom Stafford, like an "angry alligator". Rendezvous within 8 meters of the ATDA was achieved by Gemini 9 on the third revolution. The shroud had not jettisoned because the lanyards had been installed improperly with the loose ends taped down, due to "insufficiently detailed" instructions. Plans to cut the fiber glass shroud loose were considered but discarded as too dangerous to the astronauts. The flight plan was then revised and Gemini 9 completed two different equiperiod rendezvous maneuvers with the ATDA. The ATDA was left in a 290 x 300 km orbit.

The Augmented Target Docking Adapter had been prepared as a backup target in case of an Agena Target Vehicle failure. The ATDA was a short cylinder, 1.52 m in diameter by 3.33 m long, with a mass of 794 kg, consisting of a target docking adapter cone mounted on front and containing a communications system, a guidance and control system, and a reaction control system. It also had running lights, but unlike the Gemini Agena Target Vehicles, the ATDA was not stabilized and did not have independent propulsion to allow manuevers while docked with the Gemini.

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

  • 02186
  • ATDA
  • Gemini9TargetB

Facts in Brief

Launch Date: 1966-06-01
Launch Vehicle: Atlas-Agena B
Launch Site: Cape Canaveral, United States
Mass: 794 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.

Gemini 9

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