Earth To The Moon

The Missions

Gemini III

Gemini IV

Gemini V

Gemini VII

Gemini VI-A

Gemini VIII

Gemini IX-A

Gemini X

Gemini XI

Gemini XII

GXII Collection

Medallion

"The" and "End"

Gemini XII Astronauts Jim Lovell and Buzz Aldrin are shown in this Gemini XII crew photo. It has been autographed by Commander Lovell and Pilot Aldrin. Photo Credit: NASA

Gemini Titan XII marked the end of the Gemini program. A great deal about living and working in space had been learned on the previous Mercury and Gemini missions.

On nagging problem remained and that was the exhaustion suffered during Gene Cernan's and Richard Gordon's EVAs.

Better training was required to prepare the astronauts for what they would experience during a spacewalk. Training would now include many hours of working underwater in a swimming pool.

It was determined that that the neutral buoyancy obtainable in water could simulate weightlessness. The effort required to move against a viscous fluid such as water would simulate the effort required to move against a pressurized spacesuit.

Another improvement on Gemini XII would be the addition of more handholds and restraints on the spacecraft to help the astronauts position their bodies during the EVAs. While Gemini IX-A had 9 of these aids, Gemini XII would have 44.

Veteran astronaut James A. Lovell, Jr. would command the final Gemini mission. His pilot would be Edwin E. (Buzz) Aldrin, Jr. Astronaut Aldrin had received a Ph.D. from the Massachusetts Institute of Technology in astronautics in 1963. Aldrin was known in the astronaut corps as "Dr. Rendezvous" and he was instrumental in developing the procedures for rendezvous in the Gemini program.

Gemini Titan XII was schedule for launch on November 11, 1966. On their way to the launch pad Lovell and Aldrin wore signs on the back of their spacesuits. Lovell's sign had the word "The" and Aldrin's sign had the word "End". This was symbolic of the closing out of the Gemini program.

The launch of Gemini Titan XII went smoothly. There was however a problem with communications between the spacecraft and the ground. The Ascension Island tracking station had the wrong signal acquisition time and missed it communications opportunity. This meant the first 25 minutes of the flight for Lovell and Aldrin passed in relative silence.

The silence was somewhat nerve racking as important rendezvous data was needed in order for Gemini XII to rendezvous with its target Agena vehicle. Communication was established through the Tananarive tracking station and the data was relayed to the crew in time for the maneuver.

Gemini XII's onboard radar that was used for rendezvous failed during the rendezvous procedure. This failure meant that Aldrin would have to utilize the manual rendezvous procedures that he had helped develop on the ground. Consulting readings from a sextant and on board charts Aldrin provided the Gemini computer with the information it needed to calculate the numbers required for the rendezvous maneuvers.

Lovell flew the Gemini spacecraft with these numbers and achieved a successful rendezvous with the Agena target vehicle 3 hours and 45 minutes after launch. 28 minutes later Lovell had docked with the Agena.

As on Gemini XI, the crew now practiced undocking and docking. Lovell undocked from the Agena and then attempted to dock during the dark portion of the orbit. The vehicles were slightly misaligned and the vehicles latched incorrectly. After some maneuvering Lovell was able to shake free from the errant latch. Aldrin then had an opportunity to dock and docked without incident.

Gemini XII was supposed to ride the Agena to a high altitude orbit as was done on Gemini XI. During the launch of the Agena however a problem developed in the Agena's main engine. On the grounds of safety it was decided that the objective of the Gemini XII mission would be scrapped.

A substitute mission objective to photograph a solar eclipse was inserted into the mission plan to replace the high altitude objective that was scrapped. The Gemini XII crew was not pleased with the last minute changes but was able to perform the task and observe the eclipse as it progressed across South America.

The first EVA exercise on Gemini XII called for Aldrin to do a standup EVA while remaining in the hatch of the Gemini spacecraft. During this EVA Aldrin was able to get acclimated to sensations and movements experienced in zero-g and the EVA easily achieved its objectives. Aldrin closed the hatch and the Gemini XI crew began preparing to rest for the night.

The next day brought the primary objective of the mission and that was Aldrin's full umbilical EVA outside of the spacecraft. The extensive underwater training and new astronaut restraint aids served Aldrin very well. He was able to maneuver with ease to the back of the Gemini spacecraft and back to the front and work on the Agena. Aldrin practiced working on bolts with special tools and practiced unplugging and plugging electrical connectors. It was a textbook EVA.

Man had finally learned how to work in space while floating in weightlessness at the end of an umbilical cord. This was a major accomplishment in the steps toward landing on the Moon.

Similar to Gemini XI, the flight plan for Gemini XII called for experiments with the Gemini undocked from the Agena but connected by a tether. Like astronaut Conrad on the previous mission, commander Lovell found it was extremely difficult to keep the tether taught. The dynamics of the tethered system were behaving in ways that were not completely understood.

During the course of the mission the crew experienced a problem with the Gemini's power producing fuel cell. It seems that there as not enough room in the storage tank where the fuel cells byproduct water was to be stored. To compensate for this the crew was required to drink extra water from their potable water supply to make room for the water from the fuel cell. By doing this, they were able to nurse the fuel cell along and complete the mission.

Aldrin conducted a third EVA. This one again was a standup EVA. During this EVA Aldrin jettisoned equipment from his umbilical EVA that was no longer needed as well as empty food containers. The jettisoned material did not remain in orbit long and soon would be incinerated by the friction from the Earth's atmosphere.

On the fourth day of the mission, November 15, the Gemini's retro rockets were fired to bring the crew back to Earth. The reentry profile for Gemini XII also would be in automatic mode as it was for Gemini XI.

Gemini XII landed within 3 miles of the targeted landing spot on the Atlantic Ocean. As with several previous missions the prime recovery ship was the aircraft carrier USS Wasp.

The mission duration from Gemini XII was 3 days, 22 hours, 34 minutes, and 31 seconds.

The Gemini program was now complete. It was time to move on to Apollo and the Moon.