|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
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"
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
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
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
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.
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
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
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
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 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.