Gemini 8: NASA’s first near-disaster in space

Dates: 16 – 17 March 1966

Duration: 10 hours, 41 minutes, 26 seconds

Commander: Neil Armstrong (first of two spaceflights)

Pilot: Dave Scott (first of three spaceflights)

Back-up crew: Pete Conrad and Dick Gordon

Objective: To perform the first ever docking of two spacecraft, and to perform the US’ second ever EVA (spacewalk).

The Crew

Neil Armstrong (left) and Dave Scott stand in front of a radar dish at the Kennedy Space Centre’s Mission Control Centre | Credit: NASA

Neil Armstrong and Dave Scott were regarded as two of NASA’s best engineer-astronauts.

Armstrong had served in the Korean War as a Navy fighter pilot before graduating with an aeronautical engineering degree from Purdue University and becoming a civilian test pilot for NASA, where he flew the hypersonic X-15 rocket plane. Only 12 people ever flew the X-15, the same number of people who walked on the Moon, making Armstrong a member of two extremely elite clubs. He joined NASA in its second group of astronauts in 1962.

Dave Scott had initially received a swimming scholarship to study engineering at the University of Michigan but ultimately elected to attend the Military Academy at West Point. He then served as a fighter pilot in the Air Force, graduated with two advanced degrees from MIT in the same year, attended the Air Force Test Pilot School and was selected for the Aerospace Research Pilot School which helped test pilots prepare to apply to NASA. Scott was successful in his application to NASA’s third group of astronauts in 1963.

Interestingly, Armstrong was the last of his astronaut group to fly in space (save for Elliot See, who was killed in a jet crash before he got his chance), while Scott was the first of his.

‘Firsts’ for Gemini 8

Gemini 8 would perform the first ever docking of two spacecraft, a key component of a future flight to the Moon. It also marked the first time an American civilian (Neil Armstrong) flew into orbit.

The Flight

Gemini 8 lifted off on 16th March 1966 at 16:41 UTC in pursuit of an Agena Target Vehicle (an uncrewed spacecraft used for rendezvous and docking exercises).

Just under four hours into the mission, Armstrong reported they had a radar lock on the Agena and were trailing it by 179 miles. They continued to chase it down and, at 76 miles away, spotted it out of their window for the first time.

Armstrong and Scott get a close-up look at their Agena prior to docking | Credit: NASA

With Scott reading out the range and closing rate, Armstrong fired Gemini 8’s Orbit Attitude and Manoeuvring System (OAMS) and, just under six hours into the mission, carried out what was only the second-ever rendezvous in spaceflight history.

A 35-minute fly-around followed which allowed Armstrong and Scott to check the Agena and make sure it was safe to dock with. Once they were sure everything was performing correctly, they were given the go-ahead from Mission Control. “Flight, we are docked!” Armstrong reported a moment later. “It’s really a smoothie.”

The first ever docking in space had been successfully achieved, completing one of Project Gemini’s most important goals.

Just before Armstrong and Scott passed into a communications blind spot – the tracking station in Zanzibar was not operating due to political unrest in the area – CapCom Jim Lovell radioed them with a message.

“If you run into trouble and the Attitude Control System in the Agena goes wild,” he said, referring to a few issues that had been experienced with the Agena in the past, “just send in Command 400 to turn it off and take control with the spacecraft.”

CapCom Jim Lovell (left) and Bill Anders at their console in Mission Control | Credit: NASA

A few minutes later, and with Gemini 8 now out of radio contact with Mission Control, Scott sent a command to the Agena that moved them to the right slightly to keep them in an optimum angle relative to their direction of travel. Then he noticed something unusual on one of the cockpit displays. “Neil, we’re in a bank,” he warned.

For some reason, they had begun to roll past their planned position. Armstrong attempted to use Gemini 8’s OAMS to stop the roll and was briefly successful, but when he let go of the controls it immediately started back up again.

The astronauts’ first conclusion was that, as CapCom Jim Lovell had alluded to, a problem had developed in the Agena. Scott cycled the Agena-related switches in the cockpit (that is, turned them off and on again) but to no avail.

Concerned that a high rate of spin could damage both spacecraft or even cause the Agena to explode, they made the decision to undock. Scott pushed the emergency release button while Armstrong fired their OAMS again to back them away.

However, now free of the extra mass of the Agena, Gemini 8 began rolling significantly faster. It was then that the realisation dawned that the problem wasn’t with the Agena – it was with them.

A view of the Agena Target Vehicle from inside Gemini 8 just prior to their historic docking | Credit: NASA

Soon after, they came within range of one of NASA’s tracking ships.

“Gemini 8, CSQ CapCom. Comm check. How do you read?” asked the CapCom on duty, oblivious to the drama unfolding above him.

“We have serious problems here,” Scott immediately reported. “We’re tumbling end over end. We’re disengaged from the Agena.”

“We’re rolling up and we can’t turn anything off,” Armstrong added.

With Gemini 8 now spinning at over one revolution every second and Armstrong and Scott’s vision beginning to blur and fade around the edges, it was not missed on anyone that if the problem went on for too much longer, the two astronauts were in serious danger of blacking out.

In a last-ditch attempt at stopping the spin, Armstrong shut down the entire OAMS system and instead fired their Reentry Control System (RCS) thrusters, which were found on the ‘nose’ of the Gemini spacecraft.

It worked. With Armstrong’s careful input, the spin was slowly brought under control.

Now it was Mission Control’s turn to make a quick decision. Mission rules dictated that a flight be immediately aborted if the Reentry Control System was fired, lest they use up all of its fuel and get stranded in orbit, and so plans began to be rapidly drawn up to bring the astronauts back home as soon as possible.

British Flight Director John Hodge – in just his first mission in the role – decided to have Gemini 8 re-enter the atmosphere the following orbit, which allowed it to land within range of the secondary recovery forces.

Armstrong and Scott splashed down in their emergency recovery zone 800 miles off Okinawa just over ten hours after lift-off, far from the 72-odd hours that was planned.

The Navy’s recovery ships were some distance away because of the landing zone having been shifted, but the US Air Force had planes circling Gemini 8 in minutes. Three pararescuers were dropped off and attached a flotation collar to the spacecraft, joining Armstrong and Scott in preparation for the USS Leonard F. Mason’s arrival. All five got seasick as they waited.

Armstrong and Scott pose with the PARA-RESCUE team who recovered them aboard the USS Leonard F. Mason | Credit: NASA

Once they were onboard the Leonard F. Mason almost three hours after their landing, it was determined by medical crews that Armstrong and Scott were exhausted but miraculously nothing more.

Despite the astronauts’ disappointment at having to cut their mission so short, NASA managers were still very impressed with them both, Armstrong because of his quick-thinking in stopping the spin and Scott because in the middle of everything he had thought to hand back control of the Agena to the flight controllers in Houston, which allowed them to test it over the following days and rule it out as the cause of the incident.

An investigation later determined that the spin had actually been caused by one of Gemini 8’s thrusters getting stuck open after a short circuit in its wiring.

NASA management’s respect for both Armstrong and Scott was reflected in their future assignments. As we all know, Armstrong went on to command Apollo 11 and became the first person to walk on the Moon.

Scott, meanwhile, was command module pilot for Apollo 9 (where he became the first person to fly the command module solo while his crew-mates tested the lunar module) and walked on the Moon as commander of Apollo 15. At the time of writing in September 2020, Scott is one of just four people still alive who has walked on the Moon’s surface – along with Buzz Aldrin, Charlie Duke and Jack Schmitt – and is the only one of them to have done so as a commander.

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