Agena Target Vehicle
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Agena.jpg
An Agena Target Vehicle
The Agena Target Vehicle was designed to develop and practice orbital rendezvous and docking in space, in preparation for the lunar mission.
The ATV consisted of the Lockheed Agena spacecraft and the McDonnell docking adapter. The Agena was launched from AMR (Cape Canaveral) Complex 14 on top of a Convair Atlas booster. 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 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 an altitude of 400 miles (a human record at the time)
- 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.
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 (http://nssdc.gsfc.nasa.gov/database/MasterCatalog?sc=GEM6T) | Exploded during launch. 3,261-kg |
| GATV-5003 | Gemini 8 | March 16, 1966 15:00:03 UTC | September 15, 1967 | 1966-019A (http://nssdc.gsfc.nasa.gov/database/MasterCatalog?sc=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 (http://nssdc.gsfc.nasa.gov/database/MasterCatalog?sc=GEM9TA) | Failed to orbit. 3,252-kg |
| ATDA #02186 | Gemini 9A | June 1, 1966 15:00:02 UTC | June 11, 1966 | 1966-046A (http://nssdc.gsfc.nasa.gov/database/MasterCatalog?sc=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 (http://nssdc.gsfc.nasa.gov/database/MasterCatalog?sc=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 (http://nssdc.gsfc.nasa.gov/database/MasterCatalog?sc=1966-080A) | Boosted Gemini 11 to a record 1,374-km apogee. 3,175-kg. Tether experiment. |
| GATV-5001A | Gemini 12 | November 11, 1966 19:07:58 UTC | December 23,1966 | 1966-103A (http://nssdc.gsfc.nasa.gov/database/MasterCatalog?sc=1966-103A) | No apogee boost due to a defective main Agena engine. 3,175-kg. Tether experiment. |
External links
- Gemini 6/Agena target vehicle 5002 systems test evaluation (PDF) December 1965 (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19750069069_1975069069.pdf)pt:Agena