Agena target vehicle

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An Agena Target Vehicle
An Agena Target Vehicle
An Atlas launch vehicle launches GATV-5006 into orbit for the Gemini 11 mission.
An Atlas launch vehicle launches GATV-5006 into orbit for the Gemini 11 mission.
The ATDA in orbit as seen from Gemini 9A.
The ATDA in orbit as seen from Gemini 9A.

The Agena target vehicle (ATV) was a spacecraft used by NASA to develop and practice orbital space rendezvous and docking techniques in preparation for the Apollo program lunar missions.

Each ATV consisted of an Agena spacecraft built by Lockheed and a docking adapter built by McDonnell. The Agena was launched from Cape Canaveral Air Force Station Launch Complex 14 on top of an Atlas booster built by the Convair division of General Dynamics. The Agena first burn would occur shortly after shroud jettison and separation from the Atlas over the Atlantic Ocean. Over Ascension Island, a second burn would boost the Agena into a low circular orbit.

The McDonnell Gemini spacecraft would then launch (as close as 90 minutes) from Launch Complex 19 (both countdowns would proceed in parallel and required close synchronization) and, toward the end of the program, would dock with the Agena within the first orbit after launch.

The Gemini astronauts would then fly in a stabilized mode and perform a number of experiments:

  • letting the Agena stabilize the formation to save the capsule's propellants (on the first docking, during the Gemini 8 mission, a stuck nozzle on the capsule resulted in an emergency undock and the mission termination)
  • EVA and work on a tool panel (this required installing handrails on the next flight after one astronaut's heart rate exceeded safe limits due to the effort expended just holding on)
  • lighting the Agena engine and reaching a record orbital apogee of 738 miles.
  • undocking, unreeling a 50 foot (15.24 meter) nylon strap between the capsule and the Agena and flying in a "dumbbell" configuration with the Agena below the astronauts (to check the gravitational effect on the formation stability in uncontrolled mode. This is now known as Gravity-gradient stabilization.)
  • using a similar tether and a few thruster bursts to rotate the two craft around each other as an early test of artificial gravity.

After the Gemini capsule separated for the last time, the Agena remained in orbit for a short time and was used to verify the command system.

[edit] Agena target vehicle flight statistics

Agena Gemini mission Launched Reentered NSSDC ID Comments
GATV-5002 Gemini 6 October 25, 1965
15:00:04 UTC		 October 25, 1965
15:06:20 UTC		 GEM6T Exploded during launch. 3,261-kg
GATV-5003 Gemini 8 March 16, 1966
15:00:03 UTC		 September 15, 1967 1966-019A First docking. 3,175-kg. Gemini 10 later
rendezvoused with Agena 8
GATV-5004 Gemini 9A May 17, 1966
15:12:00 UTC		 May 17, 1966
15:19:00 UTC		 GEM9TA Failed to orbit. 3,252-kg
ATDA #02186 Gemini 9A June 1, 1966
15:00:02 UTC		 June 11, 1966 1966-046A Shroud did not separate. 794 kg. Built from
docking portion of Agena Target Vehicle and
Gemini reentry thruster section.
GATV-5005 Gemini 10 July 18, 1966
20:39:46 UTC		 December 29, 1966 1966-065A Boosted Gemini 10 to a 763-km apogee. 3,175-kg.
GATV-5006 Gemini 11 September 12, 1966
13:05:01 UTC		 December 30, 1966 1966-080A Boosted Gemini 11 to a record 1,374-km apogee.
3,175-kg. First demonstration of artificial gravity created in a microgravity environment.
GATV-5001A Gemini 12 November 11, 1966
19:07:58 UTC		 December 23, 1966 1966-103A No apogee boost due to a defective main
Agena engine. 3,175-kg. Tether experiment.

[edit] External links

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