The Agena target vehicle seen from Gemini 8 (NASA)

If Gemini 8 had failed, NASA would most ikely have been shut down.

Three times during the space race, NASA nearly lost a capsule and its crew. The first time was during America’s first orbital mission, John Glenn’s Friendship 7 flight, on February 20, 1962. A light went on in Mission Control indicating that Glenn’s heat shield was loose, which meant he would burn up in the atmosphere during reentry. There was a retro-rocket pack — designed to slow Glenn’s capsule enough for it to fall out of orbit — strapped over his heat shield; Mission Control worked out that if, instead of being jettisoned, it were left in place during reentry, it would hold on the heat-shield. And it did. Though Mission Control worried that if there was any rocket propellant left in the rocket-pack’s tanks, it would explode, killing Glenn. Happily, it didn’t.


Skipping ahead: The third near-fatal space-race disaster was in April 1970, when one of Apollo 13’s oxygen tanks exploded, leaving three astronauts two-thirds of the way to the Moon without enough oxygen or electricity to get home. Happily, the best engineers in the country were on hand in Houston to figure out a way to get them back before they froze or suffocated.

These are both pretty famous incidents, thanks to Tom Wolfe’s The Right Stuff and the movie Apollo 13. But the closest NASA came to losing astronauts during the race to the Moon was a little-known incident in 1966, during the Gemini missions. Specifically, Gemini 8, whose 50th anniversary has just passed. In fact, if it weren’t for the extremely quick thinking of a first-time astronaut named Neil Armstrong, Gemini 8’s crew would have been killed.


The Gemini program was a series of proof-of-concept missions designed to figure out if landing on the Moon was possible: Gemini 3 (Gemini’s first manned mission) was the first time a space capsule changed its orbit mid-flight. Gemini 4 featured the first space-walk. Gemini 5, the first use of oxygen-hydrogen fuel cells. Gemini 6 made the first-ever orbital rendezvous, with Gemini 7, which was then making the first-ever two-week space flight.

Gemini 8 would be the most complicated mission to date — the first time two objects docked in orbit. A radio-controlled “Agena target vehicle” would be put in orbit first; then Gemini 8 would launch, catch up to the Agena, and gently slide its nose into a docking collar on the Agena’s nose. This extremely delicate maneuver would be performed by mission commander Neil Armstrong, who — like his co-pilot, David Scott — would be making his first trip into space.


At first, everything went perfectly. It took about four hours for Armstrong and Scott to catch the Agena. After flying a loop around it, to make sure it hadn’t been damaged during its launch, Armstrong started to gingerly fly the Gemini capsule toward the docking collar. The speed difference between the Gemini and the Agena was 0.179 miles per hour. The absolute speed of each was 18,000 miles per hour. Mission Control heard Dave Scott announce, “We are docked! Yes, it’s really a smoothie!” — and then Gemini 8 passed into a radio-dead zone.


In Mission Control, everyone breathed a sigh of relief; they had just crossed another gigantic hurdle on their way to the Sea of Tranquillity. But then Gemini 8 came out of the dead zone, and Mission Control’s radio crackled on. It was Dave Scott’s voice:

“We have a serious problem here.”


Thrusters on both the Agena and the Gemini were firing out of control, spinning the still-connected ships wildly. Hoping the malfunction was in the Agena, Armstrong undocked — but Gemini 8 started spinning even faster. The two astronauts’ vision began to blur; they were spinning at one revolution per second and were starting to lose consciousness. Knowing he had only seconds to make a decision, Armstrong shut down the thrusters entirely. Which meant they wouldn’t spin any faster — but since there’s no friction in space, they weren’t slowing down either.

The Gemini had a backup thruster system, used only for reentry — and with only enough fuel for reentry. But Armstrong knew he didn’t have a choice; he switched to backup control, and began to manually fire opposite thrusters to stop the spin. Which worked — but in the process, used up three-quarters of the fuel Armstrong and Scott needed to get out of orbit and safely back through the atmosphere.


Immediately, Mission Control began to plan for an emergency landing, three days ahead of time. Instead of splashing down in the Atlantic, as planned, Gemini 8 would have to reenter the atmosphere beyond the range of NASA’s tracking stations, over China, and land 500 miles east of Okinawa.

Astonishingly, the emergency reentry came off without a hitch — though the remote landing spot meant Armstrong and Scott had to spend three hours bobbing around in the ocean, desperately sea-sick, while they waited for a Navy destroyer to come and pick them up. Other than that, they were perfectly okay. And they both went on to walk on the Moon.

Gemini 8 proved that NASA’s astronauts and flight controllers really did have the right stuff needed to handle life-or-death situations.

The mission was a major milestone in two ways: First, it proved that two space ships — each traveling ten times faster than a bullet — could dock in orbit. Second, it proved that NASA’s astronauts and flight controllers really did have the right stuff needed to handle life-or-death situations. In fact, several senior NASA managers have credited Armstrong and the Gemini 8 Mission Controllers with saving the space program. Less than a month earlier, two astronauts had been killed when their plane crashed during a bad-weather landing. At the time, there was growing sentiment in Congress that the Moon landing was a fantastic money-pit; a spacecraft malfunction killing two astronauts — so soon after the deaths of two others — would have been just the excuse the Luddites needed to shut NASA down.

And of course, Gemini 8 also launched the space career of Neil Armstrong — not only the first man to walk on the Moon, but the man whose steely nerves made that Moon walk possible.

(Come back this June for the 50th anniversary of Gemini 9: The Birth of the Jet Pack.)