Gemini 12: ‘Doctor Rendezvous’ masters spacewalking

Dates: 11 – 15 November 1966

Duration: 3 days, 22 hours, 34 minutes and 31 seconds.

Commander: Jim Lovell (second of four spaceflights)

Pilot: Buzz Aldrin (first of two spaceflights)

Back-up crew: Gordo Cooper and Gene Cernan

Objectives: To perform three EVAs to test out new training techniques and hardware.

The Crew

Aldrin (left) and Lovell stand in a mock-up of their Gemini capsule | Credit: NASA

Jim Lovell and Buzz Aldrin were originally named as Gemini 10’s back-up crew. Under the normal flight rotation – where a back-up crew for one flight would skip two flights and then become the prime crew for the third – they would have eventually flown Gemini 13. The problem was, there was no Gemini 13. The programme was scheduled to end with Gemini 12 and therefore Lovell and Aldrin’s assignment was a dead-end job.

However, when the original Gemini 9 crew of Elliot See and Charlie Bassett were killed in a jet crash and Tom Stafford and Gene Cernan replaced them, NASA realised they needed a new backup crew. That job went to Lovell and Aldrin, which meant they were then in line to fly Gemini 12.

That decision would change the course of Buzz Aldrin’s career, and indeed the rest of his life. When NASA was choosing who would fly Apollo 11, they wanted to choose astronauts who had already flown in space. The chain reaction caused by See and Bassett’s deaths had given Aldrin the necessary experience, experience which he was not originally meant to have. Without it, he would not have flown on Apollo 11 and would have not have become the second person to walk on the Moon.

The Flight

When Lovell and Aldrin made their way to the launchpad on the afternoon of 11 November 1966, they did so with signs hanging from their backs which read ‘THE’ and ‘END’, courtesy of their back-ups Gordo Cooper and Gene Cernan.

Lovell and Aldrin make their way to the elevator that will take them up to their spacecraft | Credit: NASA

At 20:46:33 UTC (16:46:33 local time), Lovell and Aldrin lifted off.

As had become a staple of Project Gemini, their first task was to conduct a rendezvous and docking with an Agena Target Vehicle (an uncrewed vehicle used for just such exercises).

Aldrin was the first astronaut with a PhD and had studied orbital mechanics at MIT – he was nicknamed ‘Doctor Rendezvous’ by his colleagues. His selection for Gemini 12 turned out to be a huge stroke of luck. With him and Lovell still 120 kilometres away from the Agena, the rendezvous radar onboard the spacecraft failed. Aldrin had to step in and use sextant sightings mixed with calculations from charts he himself had helped NASA create based on his work at MIT to give Lovell the information needed to complete the manoeuvre. Had any other astronaut been in that right-hand seat, the mission would likely have had to be aborted before it had even really begun.

As it was, though, three hours and 45 minutes into the mission the first rendezvous and docking of Gemini 12 was successfully completed.

Much like Gemini 11 had done a couple of months prior, Lovell and Aldrin were then able to take turns undocking and redocking. In Lovell’s initial attempt at undocking, Gemini 12 accidentally snagged on one of the Agena’s docking latches which prevented it from moving away. Lovell had to rock the spacecraft using its thrusters to force it to disconnect. Thankfully, no damage was done and Aldrin was able to carry out his part of the exercise without any further issues.

Their next task was originally going to be to burn the Agena’s propulsion system to boost them to a higher altitude, but flight controllers in Houston had noticed a potential problem with the vehicle’s main engine and decided that it should not be fired.

Instead, after their first sleep period Lovell and Aldrin used the Agena’s smaller secondary propulsion system (which was unaffected by the main engine problem) to make a few manoeuvres that allowed them to take photographs of a solar eclipse.

Partial solar eclipse as seen from Gemini 12 | Credit: NASA

A couple of hours later, Aldrin opened the hatch above his head to start a stand-up EVA, the first of three spacewalks scheduled for Gemini 12.

Over the course of two hours and 20 minutes, he conducted more photography tasks, retrieved a micrometeorite experiments package and, notably, installed a handrail which led from Gemini 12 to the docking adaptor of the Agena.

The next day, Lovell and Aldrin were woken up an hour earlier than planned after Mission Control detected a potential problem in one of their fuel cells. They were asked to take it ‘offline’ – that is, shut it down before the problem could develop any further – which they duly did.

Preparations for the second EVA went smoothly and Aldrin left the confines of the spacecraft properly almost 43 hours into the mission.

Here was where Gemini 12’s spacewalks begin to differ markedly from those conducted during the three previous missions (Gemini 9A, Gemini 10 and Gemini 11).

Aldrin was the first spacewalker who hadn’t relied heavily on flights in NASA’s reduced-gravity aircraft to prepare. Previously, they had been taken on flights in the aptly-named ‘Vomit Comet’, a plane which flew in huge arcs and which exposed the astronauts to short periods of weightlessness at the top of each one.

Aldrin trains underwater for his spacewalk | Credit: NASA

Aldrin had instead trained underwater in what was essentially an oversized swimming pool. Not only was it a much better mimic of the conditions he would experience during his spacewalk, it also meant he could simulate the entirety of it from start to finish without stopping. This was unlike the Vomit Comet which only allowed the astronauts to work in 25 second bursts with a period of up to a minute in between.

In addition to this new style of training, NASA had finally gotten round to providing handrails and footholds on its spacecraft for Gemini 12.

Aldrin was able to use the rail he had installed during his first EVA to move hand-over-hand over to the Agena, to the very rear of Gemini 12, and then all the way back to the Agena again with no problems. He took his time and made sure to rest every so often, meaning he did not get out of breath like his colleagues.

In between these traverses, Aldrin attached a tether between Gemini 12 and the Agena and carried out a variety of simple tasks at a pair of work stations. These included turning bolts and severing test cables, tests of the spacesuit’s dexterity. He had positioned his boots in what were nicknamed the ‘golden slippers’, foot restraints that he hooked his toes under to keep him in the right place.

Aldrin snaps a ‘selfie’ during his second Gemini 12 spacewalk | Credit: NASA

After over two hours Aldrin re-entered the Gemini 12 cabin and closed the hatch above him. It was the first ever completely successful EVA – Aldrin’s training techniques would be used as the basis for all future spacewalks.

That wasn’t the end of the mission though. Lovell and Aldrin were to try what was called a ‘gravity gradient stabilisation’ test. Lovell undocked from the Agena and carefully backed away, with the tether that Aldrin had attached during his spacewalk going taut. They moved to a position where the Gemini spacecraft and the Agena were lined up and pointed straight at the Earth and tried to stay in place. They managed to do so for four and a half hours before the tether was jettisoned and Gemini 12 moved completely away from the Agena.

A 100-foot tether connects Gemini 12 and the Agena | Credit: NASA

The final full day of the mission saw Aldrin complete a final spacewalk, a stand-up EVA used to get rid of any rubbish and to take UV photographs of the stars. It lasted 55 minutes, meaning Aldrin had spent a total of five and a half hours doing spacewalks during Gemini 12.

Despite then running into a few problems with their fuel cells and manoeuvring thrusters during their remaining time in orbit, Lovell and Aldrin managed to nurse their spacecraft to the end and successfully splashed down 4.8 kilometres away from the USS Wasp after 94 hours, 34 minutes and 31 seconds in space. It was the second completely automatic re-entry of the Gemini programme.

Despite the hardware problems encountered in the final few days, Gemini 12 had been a resounding success. NASA had finally completed its first ever completely successful EVA and now knew what types of training was necessary to accomplish such a feat.

Lovell and Aldrin onboard the USS Wasp at the end of their mission | Credit: NASA

When his time commanding Gemini 12 was combined with his experience during the 14-day Gemini 7, Lovell now held the record for the most time spent in space by a single person. He later extended this record when he flew as command module pilot for Apollo 8 – the first mission to leave Earth and travel to the Moon – and commanded the ill-fated Apollo 13. His record would not be beaten until the crew of the first Skylab mission in 1973 stayed onboard the space station for 28 days.

Aldrin, meanwhile, made his second and final spaceflight in 1969 when he flew as lunar module pilot of Apollo 11 and became the second person to walk on the Moon.

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