Moonshot: The Inside Story of Mankind's Greatest Adventure - Dan Parry (2009)

Chapter 4. FINDING A WAY HOME

During trans-lunar injection the crew fired the third-stage engine for less than six minutes, but it was enough to increase their speed to more than 24,000mph. 'We started the burn at 100 miles altitude,' Collins later wrote, 'and had reached only 180 at cut-off, but we are climbing like a dingbat ... At the instant of shutdown, Buzz recorded our velocity as 35,579 feet per second, more than enough to escape from the Earth's gravitational field.'1 Following a course that would put them some 40 degrees ahead of the Moon as it travelled on its path around the Earth, Neil, Michael and Buzz were now heading directly towards deep space.2 A quarter of an hour later, Mission Control lost contact with them. While this was a routine irritation during any space-flight, for the families it was worrying. In Houston, Janet Armstrong, Pat Collins and Joan Aldrin were able to hear everything for themselves. A 'squawk box' loudspeaker, installed in their homes, broadcast the repeated attempts to restore communications.

Mission Control: 'Apollo 11, this is Houston. Our preliminary data indicates a good cut-off on the S-IVB. We'll have some more trajectory data for you in about half an hour. Over.'

Mission Control: 'Apollo 11, Apollo 11, this is Houston. Over.'

Mission Control: 'Apollo 11, Apollo 11, this is Houston. Over.'

Armstrong: 'Hello, Houston. Hello, Houston. This is Apollo 11. I'm reading you loud and clear. Go ahead. Over.'

Mission Control: 'Roger, 11. This is Houston. We had to shift stations. We weren't reading you through Goldstone. We show pyro bus A armed and pyro bus B not armed at the present time. Over.'

Armstrong: 'That's affirmative, Houston. That's affirmative.'

Mission Control: 'Roger.'

Mission Control: 'Apollo 11, this is Houston. You're go for separation.'

Listening to the radio messages, Pat Collins tried to hide the tension behind a calm smile as she prepared to address the press gathered on her front lawn. She and her children – Kate was ten, Ann seven and Michael six – had watched the launch on television, accompanied by friends and relatives. Before stepping outside, Pat had told the children, 'Be polite, say that you thought it was nice or whatever you thought, and don't say too much.' The reporters were gathered around a fallen oak tree that had been brought down overnight by a thunderstorm. It had attracted quite a bit of attention in the Collins household and already somebody had called offering to chop it up. 'But that's my wishing tree,' sobbed Kate.3

Meanwhile, more than 3,000 miles above the Earth, Michael Collins was preparing for his first big test of the flight. Three and a quarter hours into the mission, Apollo 11 consisted of the command module, followed by the service module and then the adapter, the long cone-shaped container holding the fragile lunar module (which was normally abbreviated to LM and universally referred to as the 'lem'). Beyond this was the instrument unit and then finally the S-IVB third stage. Having completed the TLI burn, the third stage was no longer needed. Before it could be discarded, however, the lunar module had to be extracted from the adapter. As the command module pilot, for Michael this would be one of the most complicated and delicate manoeuvres of the mission.

Swapping seats with Neil, he climbed into the left-hand couch and for the first time took control of the spacecraft. Pushing a switch to detonate pyrotechnic charges, Michael separated the command and service modules (shortened to CSM) from the rest of the vehicle. Then, by increasing his speed by just half a mile per hour, he was able to edge ahead. After 15 seconds, he pitched the CSM up by 180 degrees so that he was looking directly back towards the adapter, now 100 feet away.4 Deprived of the CSM, the top of the slender container opened up like the petals of a flower. Four panels splayed open and then broke away entirely, revealing the precious cargo contained inside. Slowing down by the smallest margin, Collins allowed the adapter to approach them. With the Sun shining brightly on his target, he could see the LM crouching snug inside its shell. Meanwhile Buzz, who like Neil was largely a spectator during this part of the journey, was recording Michael's progress using a 16mm camera. Inch by inch, Collins flew the command module towards the LM, gently docking with it. Once he had accurately lined up the two vehicles Michael quickly operated a mechanism which automatically fired 12 spring-loaded latches, securing the connection between the LM and the command module.

Collins was dissatisfied. 'That wasn't the smoothest docking I've ever done.'

'Well, it felt good from here,' Armstrong reassured him.

Ten minutes after separation, Collins had completed the first part of his task. Sliding out of his seat he scrambled under the console in front of him and slipped into the lower equipment bay. Once he'd opened the hatch at the top of the command module Michael would later have to clear the elaborate docking mechanism out of the way. For a bon viveur who had somehow wound up as an astronaut, such fiddly mechanical work had proved difficult in training and he wasn't looking forward to doing it for real.

Armstrong: 'Well, Buzz is getting comm right now.'

Collins: 'Yes, let Buzz do his high-gain thing, and I'll get ready to go dick with the tunnel.'

On opening the hatch, Michael was struck by a smell of burning, resembling 'charred electrical wire insulation'. Later he would say it was 'enough to knock you down ... it was one strong odour'. Other astronauts have since noticed a similar sensation after completing a docking, some describing it as the 'smell of space'. (British scientists researching this phenomenon link it to 'high-energy vibrations' in particles associated with the solar wind.) Fifty minutes later, sitting back in his couch, Collins eased the command module away from the adapter, and like a cork from a bottle the LM came away with it. With its legs still folded, its protective gold foil shining in the sunlight and its two iridescent windows glinting like eyes, the LM resembled a giant insect drawn from its protective chrysalis. Flying through space, 12,600 miles from the Earth, Apollo 11 now consisted of two spacecraft, each capable of supporting a crew. Safely secured together, the two vehicles pulled ahead of the spent third stage as they continued their flight to the Moon.

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The decision to bring a second spacecraft along – with all the extra weight this implied – was one of the reasons why the Saturn V had needed to be so big. Controversial though it was, the LM was the vital component in the only viable plan to get to the Moon. When first raised, this plan was considered so risky it was barely taken seriously. It originated during the agency's first major discussions on the lunar landing and relied on concepts so ambitious they triggered one of the most emotionally charged rows in the history of NASA.

The debate arose a year before Shepard's Mercury flight, in 1960, when NASA's Space Task Group was looking for projects that could be pursued after the Mercury programme. Responsible for planning and developing manned missions, the group was led by Dr Robert Gilruth. Initially, his task was 'to put man in space and bring him back in good shape – and do it before the Soviets', but his brief later expanded. Based at the Langley Research Center in Virginia, Gilruth was a gifted aeronautical engineer who managed his team with the air of a Victorian gentleman, his reticent manner, old-fashioned values and paternal style of leadership masking his immense political acumen. Although Mercury remained the priority, Gilruth was looking towards the future. One idea involved a flight orbiting the Moon, a proposal which came to be called Apollo, after the Greek god of light. By October, staff at NASA HQ in Washington felt Apollo needed a clear objective and it was suggested the project should involve a series of manned lunar landings.5Beginning on 5 January 1961, ideas on how one might land on the Moon were presented to the agency's senior managers, and during two days of briefings it became clear that there were a number of ways this could be done.

A popular plan, known as direct ascent, suggested launching a huge rocket and sending it directly to the Moon where it would fly all the way to the lunar surface. This idea was depicted in films such as Destination Moon (1950) and adopted by Tin Tin and other space-travelling heroes. Already NASA was working on designs for a massive booster, named Nova, that would carry enough fuel to support its payload through two launches, the first from Earth, the second from the Moon. But from the start it was clear that landing such a huge rocket tail first on the Moon contained many challenges, not least the notion of an elevator that would carry the crew down to the surface.6 Many believed it would be easier and safer to land a smaller spacecraft on the Moon, though this too brought problems. How, for example, could a small spacecraft travel all the way from the Earth to the Moon and back? During the January briefing sessions, it was suggested that a small vehicle should be launched into orbit where it should rendezvous with other rockets which would supply it with the fuel for the return trip to the Moon (no existing booster could carry the whole lot into space in one go). This idea, known as earth orbit rendezvous (or EOR), was supported by Dr Wernher von Braun, a rocket engineer from Germany, caricatured by Peter Sellers in the film Dr Strangelove.

Von Braun came to be fascinated by the prospect of space travel during his teenage years, and later pursued his interest in rocket engines by designing missiles for the German army during the 1930s. A shrewd political operator, von Braun found it expedient to join first the Nazi party and then the SS, while developing what became the V-2 rocket.7 He also permitted the use of slave labour. Twenty thousand people died at the Peenemünde and Mittelwerk plants while building the V-2, the world's first ballistic missile.8 After von Braun and his team surrendered to the American army in 1945, they were sent to the States together with examples of the V-2 and boxes of supporting documents. Continuing their work, they gave the army a leading edge in developing large liquid-fuel rocket engines, supersonic aerodynamics, and guidance and control systems. Their Redstone booster was used in America's first live nuclear missile tests (and later in the initial flights of Project Mercury). In 1958, a modified Redstone, the Jupiter-C, launched the West's first satellite, Explorer 1. Meanwhile von Braun was working on designs for a more powerful booster, named Saturn – 'the one after Jupiter'. This was intended to be able to send large payloads into Earth orbit, or smaller loads into lunar orbit. By 1959, plans for the Saturn rocket had become integral to the army's Project Horizon, a proposal for a military camp on the Moon, which was just as optimistic as the Lunex Project, the air force's dream of a lunar base staffed by airmen. In the spring of 1960, von Braun was told that he and his team were to be transferred from the army to NASA, and in July he became the director of the new Marshall Space Flight Center in Huntsville, Alabama. In this capacity he was invited to attend the landing discussions in January 1961.

The briefings led to the creation of a planning group which was set up in mid-January, more than two months before Gagarin's flight. Based at HQ and chaired by the Assistant Director of Manned Space Flight, George Low, the group looked at the various ways of landing on the Moon, particularly direct ascent and EOR. Direct ascent was favoured by influential members of the team including Max Faget, the designer of the Mercury capsule. Faget was asked to examine a third idea, involving a rendezvous not in Earth orbit but in lunar orbit, but he wholeheartedly dismissed it and the group barely returned to the subject again. Low's preliminary report9 suggested manned flights to the Moon using EOR could be possible as early as 1968, while direct ascent could become a reality between 1970 and 1971. In addition to their work on a lunar landing, the group also agreed to support a second generation of spacecraft intended to maintain a presence in space after Mercury. This programme, which evolved into Project Gemini, laid the groundwork for future missions to the Moon, as did simultaneous development of the Saturn booster, the F-1 engine and hydrogen technology.10

On 22 March 1961, NASA's senior managers discussed some of these plans with John F. Kennedy, the country's dynamic new president. A written summary, sent to the White House the next day, included references to 'manned circumlunar flight in 1967', Saturn rockets, and a landing that could be 'achieved in 1970' using Nova.11 A month later, on 11 April, George Low briefed a Congress committee on plans for a lunar landing, even though nobody had yet flown in space. To demonstrate that manned missions were possible he intended to a show a film of the successful sub-orbital flight made on 31 January by Ham the chimpanzee, but he ran out of time before the committee adjourned. That night Gagarin orbited the Earth, and by the time Low returned to Congress the country was smarting from Russia's success. Low later admitted that 'we thought it would not be in our best interests to show how we had flown a monkey on a sub-orbital flight when the Soviets had orbited Gagarin'. Under pressure, NASA managers told the Congress committee that Russia might even be aiming to land a man on the Moon in 1967, the fiftieth anniversary of the Bolshevik revolution.12 Then, just as Gagarin was getting used to his new status as an international hero, American pride was further dented by the Bay of Pigs debacle, which began just days after his triumphant flight.

Kennedy had to quickly find a way of restoring national prestige. Focused on domestic priorities, he was less than dazzled by the idea of orbital flight. But with the Cold War at its chilliest Kennedy recognised that a public show of affection towards space was necessary to score major political points. With the Russians chasing a claim for technical superiority, Kennedy was advised to beat them to it. 'This is, whether we like it or not, in a sense a race,' he told James Webb, NASA's newly appointed administrator.13 Even if Mercury succeeded in putting a man into orbit, a race towards something more ambitious in space was only just beginning. The question was, what should the prize be?

On 20 April, Kennedy sent a memo to Vice-President Johnson asking whether 'we have a chance of beating the Soviets by putting a laboratory in space, or by a trip around the moon, or by a rocket to land on the moon ... ?' Johnson replied that a manned Moon landing was far enough in the future to allow the United States the possibility of achieving it first. It was an argument supported by Gilruth, who saw the project as being so technically difficult the US and Russia would each have an equal chance of success regardless of their current position. For the moment, however, Gilruth remained preoccupied with the more modest objectives of the current missions. For him great relief came with the first successful Mercury flight on 5 May. Millions of TV viewers were enthralled by the first US manned rocket launch, but behind the scenes America's ambitions were already being propelled towards bigger ideas.

In deciding to back a manned landing, Kennedy gave NASA the relevant parts of a forthcoming speech proposing a flight to the lunar surface in 1967. Since they still did not know how such a mission could practically be accomplished, NASA's managers urged him to put back the date. On 25 May, Kennedy told a joint session of Congress, 'I believe that this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the Moon and returning him safely to Earth. No single space project ... will be more impressive to mankind or more important ... and none will be so difficult or expensive.' The question of how far Kennedy was prepared to stomach the costs involved remains a subject of debate, but publicly he needed to send the right signal. The president recognised that such an effort in such a short timeframe would require a monumental commitment on a wartime scale. 'It will not be one man going to the Moon,' he added, 'it will be an entire nation. For all of us must work to put him there.'14 Gilruth doubted it could be done in the time available.

Given a shot in the arm by the commitment from Kennedy, NASA managers commissioned studies on the various landing options. Once it was realised that a huge rocket such as Nova could never be developed within the president's deadline, and the whole idea of direct ascent was left to sink into a fug of equations. With Nova stranded on the drawing board, interest veered towards von Braun's work on EOR. Although his rockets were smaller and more feasible than the Nova, his vision of two spacecraft successfully finding each other for a safe rendezvous in space remained a daunting prospect. At least if the rendezvous failed, the astronauts could be quickly brought home.

This was a comforting thought compared to the nightmare inherent in a proposal put forward by NASA's Langley Research Center. Supported by John Houbolt, a tenacious engineer with a passion for his work, the Langley plan also involved a rendezvous in space but suggested this take place not above the Earth but three days away, above the Moon – an idea that 'horrified' Low.15 Direct, to the point of being blunt, Houbolt refused to let the idea drop. He suggested that lunar orbit rendezvous (LOR) required only a very small capsule to be sent to the surface of the Moon. Unencumbered by the resources necessary for a six-day round trip to and from Earth, the capsule would only have to fly from lunar orbit down to the surface and back again. It would then rendezvous with a bigger vehicle for the journey home. Small and lightweight, it would be far easier to land than the large spaceship envisaged in EOR, never mind the mammoth Nova. In fact, Houbolt argued, LOR was 50 per cent lighter than direct ascent. Nevertheless, the plan meant that men returning from the lunar surface would have no way of getting home if they failed to find the vehicle waiting for them. The Moon was more than 2,000 miles wide. Yet if it were difficult to find a moving target as big as this, how was anyone going to be expected to find a small orbiting spacecraft? If things went wrong, there would be no hope of rescue. Forced to contemplate the prospect of dead astronauts perpetually trapped in orbit around the Moon, in June staff at headquarters rejected the idea.16

Difficult as they were for some to accept, Houbolt's proposals were inspired by a logic that could not be dismissed. Nova was too impractical and EOR raised too many technical questions. Houbolt knew there wasn't time to pursue anything other than LOR, but for months he found there was 'virtually universal opposition – no one would accept it – they would not even study it'.17 'The critics in the early debate murdered Houbolt,'18 von Braun later remembered. Bypassing several layers of management, six days before Kennedy's announcement Houbolt had put his arguments in a letter to the second most powerful man in NASA, Robert Seamans. Kennedy's deadline only served to harden Houbolt's opinions, and in November – still facing opposition to his ideas – he wrote to Seamans again. 'Do we want to go to the moon or not?' he demanded, asking, 'why is a ... scheme involving rendezvous ostracized or put on the defensive?'19

Over time, senior figures slowly came round to Houbolt's point of view including, in January 1962, Gilruth. He had been instructed to take his Space Task Group from Virginia down to Houston and there set up a site under the new name of the Manned Spacecraft Center. Once in Houston, Gilruth's group began to look seriously at LOR, while von Braun's team at the Marshall Space Flight Center continued to study EOR. Each side sought the commitment of headquarters, and with tensions running high an argument on the subject broke out within earshot of the press while Kennedy was visiting Marshall.20 Without a decision, it was impossible to move forward. Aware of the difficulties of EOR – and of the president's deadline – in June von Braun came to accept that the only viable option was lunar rendezvous. It was the final move in the game: on 11 July 1962, NASA decided in favour of LOR. 'It is my opinion to this day,' Low wrote twenty years later, 'that had the Lunar Orbit Rendezvous mode not been chosen, Apollo would not have succeeded.'21

With Apollo free to move forward, Gilruth was now able to devote his attention to the fledgling Gemini programme, believing this would provide the experience in space-flight needed to fly to the Moon. Beyond spacesuits and extra-vehicular activities (EVAs), a pressing priority was to begin work on rendezvous techniques. Any lunar landing relying on a rendezvous in space would be impossible if Gemini failed to prove it could be done. On 3 June 1965, shortly before Ed White began the first US space walk, the commander of Gemini 4, Jim McDivitt, tried to fly alongside the abandoned upper section of their two-stage rocket. Although such a manoeuvre had never been performed before, McDivitt assumed it would be relatively straightforward. But each time he attempted to approach the rocket stage he found that it mysteriously moved further away, and amid concerns over using up fuel he was ordered to abandon the experiment. By the time Gemini 5 reached orbit two months later, new training techniques had been developed and the spacecraft was fitted with a radar system. The crew successfully flew from one point in space to another, demonstrating for the first time an ability to reach a pre-determined position in orbit.

Only through practical experience of orbital mechanics was NASA able to get to grips with the difficulties of rendezvous. McDivitt had expected to catch up with his target by firing his engine, with the intention of going faster. Actually the burn simply pushed him into a higher orbit, which left him travelling more slowly relative to anything at a lower altitude – like a spent rocket stage. With the target in sight, McDivitt ought to have slowed down. In doing so he would have become more vulnerable to the pull of the Earth's gravity, which would have taken him down to a lower – and faster – orbit. When he was in the right position he could have fired his thrusters and climbed back up to meet his target. Such logic wasn't for the faint-hearted. Once digested it was supplemented with side orders of apogee adjusts, phase adjusts, plane changes and coelliptic manoeuvres, spiced up by the differences between near-circular and elliptical orbits. In short, a successful rendezvous requires an understanding of the relationship between a spacecraft's speed and its height above the Earth (or the Moon).

While Gemini 5 proved the theory, it did not approach any target but simply completed a rendezvous with an empty point in space, following a plan designed by Buzz Aldrin. It was left to the next two missions to show that NASA could indeed perform a rendezvous as required by LOR. Relying on his basic flying skills and supported by a computer, on 15 December 1965 Mercury veteran Wally Schirra flew Gemini 6 to within one foot of Gemini 7. The two spacecraft orbited the Earth three times while flying in formation, at one point maintaining their positions so accurately that neither crew had to fire their thrusters for 20 minutes. The Russians had not yet managed to do the same thing with a similar degree of accuracy, and for the first time in the space race NASA was edging ahead.

The next stage was docking. Rendezvous involved two spacecraft finding and approaching each other, but only by demonstrating an ability to dock could NASA show that LOR was feasible. The first test was given to Gemini 8, to be commanded by Armstrong. Neil had been part of the backup crew on Gemini 5 before becoming one of the few astronauts to be given a command position on his first flight. Approaching from behind and below, Armstrong rendezvoused with an Agena target vehicle (a converted rocket stage). After gently approaching it at three inches per second, on 16 March 1966 he completed the first successful docking. 'Outside in airless space,' Armstrong later recalled, 'there was only silence, but in the cockpit we heard a slight thud. We relaxed for the first time.'22 The final moments took place during darkness; Armstrong remembered that 'you saw stars up above, and down below you might see lights from a city or lightning embedded in thunderstorms'.23

Neil, and his pilot Dave Scott, had been warned that the Agena may have been experiencing guidance problems, and soon after docking they found they were being rolled over. They stopped the problem by using the Gemini spacecraft's own thrusters, but only when they turned the Agena off did they feel that they had the problem under control. Then it started again. Armstrong noticed that the fuel used by their thrusters had dropped to 30 per cent and it dawned on him and Scott that the problem was not with the Agena but with the Gemini. The roll reached the point where Armstrong felt that the 'stresses might be getting dangerously high', and the two spacecraft might break apart.24 He wanted to pull away from the Agena, but with dangerous levels of 'rotation in all directions' he knew he risked a collision. Eventually he was able to pull away, but the problem returned, and with the spacecraft now revolving faster than one revolution per second it was quickly becoming one of the most dangerous moments in space-flight history.

'The sun flashed through the window about once a second,' Armstrong noted. Out of radio contact with the ground, the vehicle was spinning round and round so fast that the crew, now suffering from tunnel vision, were close to losing consciousness.25 'I could tell,' Armstrong later said, 'when I looked up above me to the controls for the rocket engine that things were getting blurry.'26 He had no choice but to shut down the thrusters. Investigating the problem in the analytical style he developed as a test pilot, Neil successively fired each of the small boosters and found that one had become stuck in the 'open' position. By activating the re-entry control system he was able to fly the spacecraft safely, but according to the mission rules this action obliged him to return to Earth as soon as possible. Less than eight hours after launch, a decision was made to end the flight early. Armstrong felt frustrated and depressed at being unable to complete the mission, but his cool handling of the emergency won him much praise within NASA's higher echelons.27

Next to fly were Tom Stafford and Gene Cernan aboard the ill-fated Gemini 9 flight. They had hoped to dock with a second Agena, but when it dived into the Atlantic shortly after launch it had to be hurriedly replaced with another target device which itself malfunctioned once in orbit. After its protective shroud failed to detach properly, Robert Gilruth called a meeting in Houston to discuss the problem. Buzz Aldrin, serving as Cernan's backup, suggested that Gene try to remove the shroud during an EVA – an idea that appalled Gilruth. 'What in hell did you say?' Deke asked Buzz a few days later. 'He's all pissed off at you. Said he had had great confidence in you and now he wants you taken off Gemini 12.' After Buzz explained what had happened, Deke ordered him to wait in his office. While Aldrin paced up and down, Slayton chased after Gilruth, returning three hours later. 'Everything's cool, you're on,' grunted Deke, adding, '... but listen Buzz, why don't you use me as your translator from now on?'28 Although Slayton had rescued his career, Buzz had inadvertently made things more difficult for himself. He now needed his mission to be a success more than ever – and relying on the success of a Gemini mission was a risky strategy.

While the science of rendezvous was now well understood, docking had been achieved only once, and even then it had been aborted early – and never had a range of tasks been successfully completed during an EVA. With just three flights left, NASA was struggling to achieve the objectives necessary to convince Washington and the country that it was able to fly to the Moon. As well as national prestige, billions of taxpayers' dollars were at stake.

Gemini 10 launched on 18 July 1966, and much was expected of its crew, which included Michael Collins. To the joy of those on the ground, Collins and his commander, John Young, successfully docked with an Agena in low orbit. Together the two spacecraft then climbed to a record 475 miles – higher than any previous flight. 'I don't know whether to laugh or to cry,' Collins later wrote, 'when I think of all the pioneer aviators who have aspired to this record and who have put their reputations, money and lives into seeking it, and now John and I are handed it on a platter.'29

As Collins prepared for the first of two EVAs, Mission Control urged the astronauts to talk more about what they were doing. In return they were given news of home, including an update on a game between the Houston Astros and the New York Mets. 'Jesus Christ!' an exasperated Collins later said. 'Here I am asshole deep in a 131-step EVA checklist and they want to talk about baseball! One little boo-boo at this stage of the game and all the oxygen will depart my suit and I will die, and they will be talking about the colour of the infield grass.'30 His first EVA involved taking pictures while standing up in the open hatch, and although the spacecraft was in darkness Collins found that there was 'just enough of an eerie bluish-grey glow to allow my eye to differentiate between clouds and water and land ... We are gliding across the world in total silence, with absolute smoothness.'31

Once the EVA was completed, Collins and Young rendezvoused with the Agena previously abandoned by Armstrong. Still tethered to the Gemini, Michael climbed out of the hatch and pushed himself away. 'Flying' through empty space towards the booster, Collins became the first person to meet another vehicle in orbit, and while hanging on to the Agena's docking adapter (last used by Armstrong's spacecraft four months earlier) he controlled his movements with a gas-gun similar to that used by Ed White. Although restricted by a lack of handholds, he retrieved an experimental panel which had been collecting micrometeoroids, thereby accomplishing a primary objective of the mission. Collins encountered occasional difficulties in mobility, and concerns about the spacecraft's limited fuel eventually forced him to cut short his EVA before he could complete a thorough testing of the gas-gun.

By the time Gemini 10 returned to Earth, NASA could show that the difficulties of rendezvous and docking had been mastered, yet still EVA remained a worrying challenge. During the next mission, Dick Gordon's space walk had to be brought to an early halt after he began to grow increasingly tired. This left it to the final flight in the programme to accomplish the last of Gemini's objectives. It would be down to Buzz.

As he and his commander, Jim Lovell, approached Guenter Wendt, moments before boarding their spacecraft in November 1966, a home-made sign on Lovell's back read simply 'The', and another on Aldrin's said 'End'. In the hope of avoiding any further EVA problems, Buzz was required to complete a series of basic mobility tasks which he considered as 'nothing more than the average suburban handyman might perform in his garage on a Saturday afternoon'.32 A monkey could carry out such tasks, Buzz felt, on one occasion going so far as to ask those around him for a banana. (Later in Houston, Buzz recalled, 'parties unknown to me kept a supply of bananas in my office'.33) His principal task was to demonstrate that he could operate easily while weightless. During preparations for Gemini 10, a facility in Baltimore had shown that by training under water an astronaut could replicate some of the conditions of weightlessness. Collins didn't make use of this, being far advanced into his training programme, and Gordon felt the same way. When Aldrin discovered what was possible in the pool he spent much time practising under water, becoming the first astronaut to train substantially for his mission in this way.

Although Buzz was frustrated by the lack of a more challenging objective, he looked forward to the chance to participate personally in a rendezvous. Shortly after arriving in space the vehicle's radar failed, and Aldrin – the master of rendezvous techniques - suddenly found himself blessed with an opportunity to show the world that all his hard work on the subject was not just an obsessive pursuit but was of practical application. Aldrin had brought with him the charts he had spent years working on, both at MIT and later in support of the pioneering rendezvous mission achieved by Geminis 6 and 7. Using these, and a sextant, he was able to guide Lovell towards a manual rendezvous with their Agena target vehicle. Later, during his EVA, Buzz successfully manoeuvred himself over to the Agena, as Collins and Gordon had done before him. But his underwater training paid off, and after comfortably returning to the spacecraft he felt fresh and alert. Later, during his next task, he unpacked equipment stowed at the rear of the vehicle – finding along the way a bright yellow picture of a banana – before methodically tackling the rest of his objectives. Working '160 miles above the surface of the Earth there was no awareness of height at all', Buzz later remembered. 'I was secure and comfortable – though encumbered – in the spacesuit. I felt enclosed and safe.'34 Aldrin went on to complete a flawless EVA lasting more than two hours. Two further EVAs, performed while standing in the open hatch, were also successful, and by leaning out of the spacecraft Buzz could all but hear the huge sigh of relief on the ground. He spent a total of five hours and 26 minutes exposed to the vacuum of space, all the while calmly controlling his mobility.

Aldrin had flown into space fearful of being doubted by Gilruth and Slayton; he came back a man NASA needed to get the job done. Dr Rendezvous, who on occasion had been a subject of amusement among his colleagues, had demonstrated prowess in space, and in the Astronaut Office nothing counted for more. Gilruth was delighted. At the post-flight party he told Joan how pleased he was, both with the rendezvous charts Buzz had prepared and with the overall success of the EVAs. For Buzz, 'those were the very words I needed to hear'.35 Project Gemini had ended on the triumphant note all involved had hoped for, not least Aldrin. All the years of hard work, all the misunderstandings, all the frustration and tension had culminated in a clamour of achievement that was a defining moment in his life.

But amid the sense of relief was something else. 'I felt an almost overwhelming sense of fatigue mixed with a vague sadness,' Buzz later said. 'I yearned for sleep so strongly.' He was unable to leave his bed for five days, at the time blaming exhaustion. In truth, he missed the signs of something more sinister that was to haunt him in the years to come.36