Gemini 6
| Mission emblem | |||
|---|---|---|---|
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| Mission dates | |||
| Mission: | Gemini 6A | ||
| COSPAR-ID : | 1965-104A | ||
| Spacecraft: | Gemini 6 | ||
| Launcher: | Titan II Gemini 62-12561 | ||
| Crew: | 2 | ||
| Begin: | December 15, 1965, 13:37:26 UTC | ||
| Starting place: | LC-19 , Cape Canaveral | ||
| Landing: | December 16, 1965, 15:28:50 UTC | ||
| Landing place: |
Atlantic 23 ° 35 ′ N , 67 ° 50 ′ W |
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| Flight duration: | 1d 1h 51min 24s | ||
| Earth orbits: | 16 | ||
| Recovery ship: | USS Wasp | ||
| Orbit inclination : | 28.97 ° | ||
| Apogee : | 259.4 km | ||
| Perigee : | 161 km | ||
| Covered track: | 694,415 km | ||
| Team photo | |||
 from left Tom Stafford and Walter Schirra |
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| ◄ Before / After ► | |||
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Gemini 6 (GT-6, also Gemini 6A , officially Gemini VI-A ) was a manned space flight as part of the American Gemini program .
The crew
Shortly after the landing of Gemini 3 , on April 5, 1965, NASA announced that the roles of main and reserve crew would be swapped for the next available mission, Gemini 6 (the Gemini 4 and Gemini 5 crews were already in training) . The Mercury veteran Walter Schirra was assigned as the commander, and the space novice Tom Stafford as the pilot . The Gemini-3 astronauts Virgil Grissom and John Young were assigned to the reserve team.
preparation
Gemini 6 should be the first flight in the program in which the spaceship should approach a target satellite that was launched shortly before ( rendezvous ) and dock to it ( docking ). A planned disembarkation from the spaceship was deleted from the flight plan in July 1965.
The Gemini spacecraft was delivered to Cape Kennedy on August 4th, and the Titan rocket was erected on the launch pad on August 31st. Work was delayed due to a hurricane and the spacecraft was mounted on the launcher on September 17th.
Gemini 6 was scheduled to launch on October 25th. Shortly before, the GATV-6 target satellite was launched with an Atlas Agena rocket , but the Agena stage did not reach Earth orbit . Apparently the launcher had exploded. The start of Gemini 6 was then canceled. Schirra and Stafford, who were already in their spaceship, had to get out again.
The idea of a double start
For a short time there was frustration at NASA, but then the bold idea arose that instead of an Agena, a Gemini spaceship should serve as a rendezvous target. The main difficulty with this was that two Gemini launches would have to occur within two weeks. But that was hardly possible because there was only one launch pad available and the necessary tests took several weeks.
In just three days, all technical problems were addressed and declared solvable. The possibility of a double flight was so important that President Lyndon B. Johnson personally announced the project on October 28th. The start was announced for January 1966, but internally they were working towards a date in December.
One of the problems was that all the ground stations that tracked the orbits of the Gemini spaceships had to be able to maintain connections with both spaceships at the same time, be it for voice or for telemetry .
The flight was renamed Gemini 6A to clarify that the mission profile had changed. The start of Gemini 7 , which set out on a long-term flight with Frank Borman and Jim Lovell , was supposed to happen first, so the numbering was no longer chronological.
Liaison officers ( Capcom ) for Gemini 6A were the same four astronauts who were already in contact with Gemini 7 : Alan Bean , Elliot See , Charles Bassett and Eugene Cernan .
Double start and start abort
Immediately after the successful launch of Gemini 7 on December 4th, preparations began for the launch of Gemini 6A. The construction work and tests went so smoothly that the start originally scheduled for December 13th was brought forward to December 12th.
Preparations were normal, but events precipitated shortly before take-off: the engines had already ignited when a poorly fastened cable came off the rocket. This cable should only fall off when taking off and start a clock in the cockpit. Since the clock was running, but the rocket did not move, the engines switched off again automatically. Schirra saw the running clock, which signaled the take-off, and noticed the shutdown of the engines. That signaled the greatest danger, because obviously the start that had just taken place had failed. Actually, Schirra, as the commander, should have released the ejection seats for himself and Stafford, because a fully fueled missile that falls back on the launch pad shortly after takeoff can only explode. But Stafford mistrusted the watch because he hadn't felt any upward movement. So he stayed calm and only reported that the engines were switched off. After it was clear that the rocket would not explode and that the ejection seats were still secured, Schirra and Stafford were taken out of the Gemini spaceship. The start was postponed for several days.
During the investigation it was found that not only were some cables sitting quite loose, but also that a dust cover was forgotten in one of the engines, which would have led to the take-off being aborted regardless of the cable falling off.
Flight history
The third attempt to start on December 15th took place without any problems. In the fourth orbit, Gemini 6A met Gemini 7, which had been in orbit for eleven days . Schirra and Stafford got within 40 meters of Gemini 7 when the two spaceships came to a standstill relative to each other.
The Soviet Vostok spaceships had already approached each other in 1962 and 1963, but this was based on precise orbital calculations at the start, and not on the control of the spaceships themselves. Thus, the maneuver of Gemini 6A and Gemini 7 was the first controlled rendezvous in space travel.
Gemini 6 still had enough fuel to perform various maneuvers and to get within 30 cm of Gemini 7. On one occasion Schirra and Stafford inspected the stern of Gemini 7, on another they flew nose to nose. Gemini 7 had been in space for a long time and no longer had such large fuel reserves, so that Borman and Lovell served more as a passive target than actively steering them themselves.
During the rendezvous, Lovell asked from Gemini 7: "What's the view?" Schirra replied: “Pretty bad. I can see through the window and see you guys in there. "
Since all objectives of the mission were met, the landing of Gemini 6A was initiated after just one day of flight. For the first time, the splashdown was broadcast live on television. Schirra and Stafford let themselves and the landing capsule be hoisted aboard the USS Wasp .
Significance for the Gemini project
Gemini 6A and Gemini 7 impressively showed how precisely the Gemini spaceships could be controlled. Changes in speed of only 3 cm / s allowed very fine changes in flight paths. The next flight, Gemini 8 , should then, as already planned for Gemini 6, dock with an Agena target satellite, another step on the way to the moon flight.
See also
Web links
- Gemini 6 in the NSSDCA Master Catalog (English)
- NASA: Gemini-6A mission summary (English)
- Gemini 6A & 7 Rendezvous Video (MPEG; 28 seconds; 2.0 MB)
- Radio communication protocols (PDF; 1670/129 pages; 77/3 MB)
