The Launchbox, Pod 14: The Near Misses of Gemini (Part 2)

By Andy Cooke

Last time, I got up to the marathon trip of Gemini 7 – where Frank Borman and Jim Lovell (who would later be part of the first Apollo crew to circle the Moon in Apollo 8) spent a marathon fortnight in a spacecraft which had a similar amount of living space to an average sportscar.

As it happens, though, I missed out one potential PoD. When the flight plan for Gemini 6 was changed to a rendezvous with Gemini 7 following the loss of the original Agena target vehicle for Gemini’s planned docking attempt, there was a proposal that an astronaut could swap between Gemini 6 and Gemini 7 (the co-pilots to trade places following a common spacewalk). The commander of Gemini 7, Frank Borman, quashed it firmly due to the risks involved – the spacewalking astronauts would have to detach completely from life support from the spacecraft in order to accomplish swapping connections, relying totally on the backup systems. He ended up saying “Wally [Schirra – from Gemini 6] could have had all the EVA he wanted. But I wasn’t going to open the hatch.”

What if it had gone ahead? A success would have been a spectacular win. But if any of Borman’s concerns had come up, it could have been a tragedy.

Gemini 8

Gemini VIII approaches the docking collar of the Agena target vehicle. Image: NASA/Dave Scott

Gemini 8 is one of the best-known near-misses of the Gemini Programme. The first successful docking in space, commanded by Neil Armstrong (on his first mission) and Dave Scott, it initially looked like it was all going well. The Agena target vehicle made it into space with no problems, the Gemini spacecraft launched with no issues, and Armstrong and Scott tracked down the target, rendezvoused and docked successfully. Next step was for Scott to carry out a spacewalk, but that wouldn’t be for a short while yet.

Half an hour later, it all went wrong. The combined assembly started to roll for no apparent reason, and accelerated. The crew had been warned that the Agena’s attitude control system might be faulty and had been told “ "If you run into trouble and the attitude control system in the Agena goes wild, just . . . turn it off and take control with the spacecraft."

They turned off the Agena systems, which initially seemed to fix the problem – but then they started to roll again, faster than before. They tried to cancel the roll with the Gemini’s thrusters, but were simply pouring through their reaction fuel. The spinning got worse and worse, and the combined assembly was now yawing wildly while spinning. The g-forces were coming close to causing the astronauts to black out – and for the assembly to reach its structural limits. Armstrong undocked, in order to leave the damaged Agena behind to spin on its own.

Unfortunately, the stuck thruster was on the Gemini, and it only got worse without the extra weight of the Agena. Armstrong shut down the entire reaction control system and switched to the re-entry control system, and brought the spacecraft under control – but at the cost of three-quarters of their re-entry fuel. The crew asked to press on with the mission (and Scott’s spacewalk), but Mission Control ordered an immediate re-entry.

What If: The astronauts had blacked out after all? There was no facility for remote control of re-entry. The Gemini would have continued spinning – there was no air friction to slow it down – so the astronauts wouldn’t have recovered consciousness.

There's one further, less obvious what-if here as well. Most people who consider this mission stop thinking about the planned activites after the docking and spinning. But given that the stuck thruster was on the Gemini and that it worked fine for several hours until randomly sticking open... what if it continued to work fine for another few hours and stuck open after that? The mission would have carried out the docking and all docked manouevres with no problems. And then, after Scott got out of the capsule on his spacewalk, unaccountably started spinning...

Gemini 9

The prime and backup crews for Gemini 9. Elliot See and Charlie Bassett front; Tom Stafford and Gene Cernan at the back. Image: NASA

The major what-if for Gemini 9 happened before the mission was even launched. The crew (Elliot See and Charlie Bassett) flew up to the spacecraft assembly plant in St Louis to see their spacecraft, followed by their backup crew (Tom Stafford and Gene Cernan) in a separate aircraft. Poor visibility at the McDonnell airfield in St Louis caused both aircraft to overshoot the runway. See went into a visual circling approach, followed by Stafford. The visibility deteriorated further and Stafford aborted his own circling approach and pulled up into the clouds to go around again at higher altitude for another try at an instrument landing. See completed his circle, came around, and descended too rapidly and off to one side of the runway, realised he was in trouble, hit the afterburner, pulled up and across – and slammed into the building where his spacecraft was being constructed.

See and Bassett died on impact.

Stafford and Cernan were moved up to prime crew, and Jim Lovell and Buzz Aldrin moved from being backup crew for Gemini 10 to backing up Gemini 9. This meant that both would now fly on Gemini 12, the last planned Gemini mission.

Gemini 9 was to be primarily a redo of the original Gemini 8 flight plan – especially needing to prove the astronaut’s abilities in EVA (extra-vehicular activity). After all, while Gemini 4 had proven that an astronaut could leave the vehicle and survive, they needed to work in space.

Unfortunately, as with the original Gemini 6 mission, the Agena target was destroyed after a launch failure. This time, they had a contingency plan – an “Augmented Target Docking Adapter” (ATDA) would be launched. Simply an inert vehicle with no engine of its own, the simpler vehicle was successfully launched two weeks later.

On its second attempt, Gemini 9 launched on June 3rd 1966. When it rendezvoused with the target, they passed on bad news to Mission Control: the nose shroud of the ATDA had not jettisoned. A band around the shroud had been incorrectly attached. Stafford reported “It looks like an angry alligator”

The "angry alligator" - the ATDA seen from Gemini 9. Image: NASA

Although the astronauts suggested “nudging” the “jaws” open with their own spacecraft, Mission Control refused and scrapped the docking attempt. Backup pilot Buzz Aldrin suggested that Cernan, on his spacewalk, cut the electrical wires on one side of the shorud – causing the steel bands to immediately straighten and snap open. Mission Control were unimpressed with the suggestion, given the sharp edges bristling on the ATDA and the unpredictable springing of the released band. Slayton later wrote that he had a tough time persuading the top officials to let Aldrin keep his place on Gemini 12.

The docking attempt was scrapped.

After practicing different rendezvous profiles, on the third day, Cernan began his EVA. An EVA which he would later describe as “The Spacewalk From Hell”

The reports from Gemini 4 led NASA to believe that EVAs would be easy. Ed White reported euphoria and floating easily. What he had not done, though, was attempt to do any work on any other object in space. The lack of gravity to anchor an astronaut made it a challenge to begin with; the rigidity of the gloves and limbs (under pressure from the oxygen in the suit) made it even worse. Future spacewalkers in Gemini and Apollo would practice their grip strength by squeezing squash balls regularly.

Cernan ran into multiple difficulties as he attempted to move backwards over the spacecraft and its attached Service Module to the parked “Astronaut Maneuvring Unit” – a self-contained rocket backpack to fly in space separately from the Gemini (something that would finally be proven in 1986 by Bruce McCandless on a Space Shuttle flight). There were few railings or easy places to grip and whenever he put any pressure on the vehicle, he would be pushed away into free space.

Exhausted, and with his heart rate passing 155 beats per minute, Cernan finally made it (past the jagged edges of the Titan shroud – something else to be changed in future missions) to the AMU.

Even donning the backpack and attaching the hoses was a challenge. In Cernan’s own words from “The Last man On The Moon”:

“Why is floating in space and turning a few dials so difficult? Let me give you a couple of tests. Connect two garden hoses and turn on the water. Now, using only one hand, try to unscrew them. Or hold a bottle of soda at arm’s length and, using a single hand, remove the twist-off top. For extra reality, run a mile before you start so you’re nice and tired, do it wearing two pairs of extra-thick gloves and close your eyes to simulate being unable to see. Stand on your head while doing some of the things to resemble tumbling in space. You get the idea.”

His visor fogged over, and Mission Control scrapped the AMU flight.

Getting back and getting back in would be dangerously challenging enough. After finally and laboriously getting back to the hatch, Cernan had to try to fold his now-unyielding space suit to get back in. After a long and painful fight, ratcheting the hatch down on the top of Cernan’s helmet bit by bit, they finally sealed the spacecraft. Repressurising the spacecraft meant they could release the pressure in Cernan’s suit and properly unfold.

What if Cernan had been sent over to try to cut the shroud? Success could have caused NASA to be unrealistically overconfident in the abilities of astronauts on EVA; a snap-back of the shroud could have caused Cernan’s suit to be punctured. Or what if NASA had realised in advance the difficulties of working on EVA and provided better handholds and railings? Cernan might have been less fogged over when he got to the AMU and the free flight gone ahead – with a partly exhausted astronaut, and with the visor possibly fogging over while he was in flight. This may seem unlikely, but NASA had already cancelled activities and would have preferred to retain more from the flight – and found it difficult to believe how difficult the activities actually were. The astronauts themselves tended to downplay the difficulties while in flight, as well.

What If...

NASA were pushing the envelope throughout with the Gemini programme. This week’s what ifs are:

  • What if the suggested spacewalk transfer between Gemini 6 and 7 had gone ahead? Success could have provided a spectacular result; failure could have caused embarrassment or even fatality.

  • What if the Gemini 8 astronauts had blacked out in their spinning? Losing Neil Armstrong and Dave Collins at that stage would have had severe repercussions for NASA – and, of course, resulted in changing the identity of the first man on the Moon.

  • What if the Gemini 8 stuck thruster had occurred a little later in the mission - working fine throughout the docking with the Agena and all docked manouevres and failing exactly as it did in OTL later on - when Dave Scott was floating outside of the capsule on his EVA?

  • What if Elliot See and Charlie Bassett had not died in the plane crash in St Louis? Regardless of the differences in potential performance of Bassett and Cernan on the Gemini 9 spacewalk, it is certain that Buzz Aldrin would not have been on Apollo 11 – he would not have flown in space in the Gemini programme.

  • What if Cernan had attempted to cut the shroud on the Gemini 9 ATDA? A snapback could have been disastrous; a success could have allowed the docking manouevre to be carried out, increasing NASA's knowledge and confidence.

  • What If NASA had realised the difficulties with EVA work and provided better handholds and railings? It would still have been extremely challenging, but they might have given the go-ahead for Cernan to attempt using the AMU with a partly-fogged visor, which could have fogged over in flight.


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Andy Cooke has written the sci-fi Endeavour trilogy (The End and Afterwards, Diamond in the Dark, Beyond the Sunset) and the political alternate history Lectern books (The Fourth Lectern, The Fifth Lectern), published by SLP.