Category Escaping the Bonds of Earth

In spite of Young and Collins’ success, one particular aspect of Gemini XI caused the most worry: the desire to complete rendezvous and docking with the Agena-D target on their very first orbit! To be fair, ‘desire’ is probably the wrong word. The necessity for rendezvous and docking at such an early stage would be essential when an Apollo command and service module was approached by the ascent stage of a lunar module after the Moon landing.

‘‘There was a lot of concern that it wasn’t going to be successful,’’ Gordon told Neil Armstrong’s biographer James Hansen. ‘‘For the Apollo application, the desire was to rendezvous as rapidly as possible because the lifetime of the LM’s ascent stage was quite limited in terms of its fuel supply.’’ To accomplish this first-lap rendezvous and docking, Gemini XI would have to meet a launch window barely two seconds long and Conrad and Gordon’s three days aloft would also feature a lengthy spacewalk, experiments … and the physical tethering of their spacecraft to the Agena target.

The purpose of the latter, said backup command pilot Neil Armstrong, was to ‘‘find out if you could keep two vehicles in formation without any fuel input or control action’’. Armstrong had been teamed with rookie astronaut Bill Anders to shadow Conrad and Gordon’s training regime and the foursome frequently found themselves in the Cape Kennedy beach house over the summer months of 1966, running through rendezvous and docking procedures, trajectories and flight plans. Before too many more years had passed, all four of them, on three separate missions, would apply this knowledge on flights to the Moon.

Conrad’s assignment to Gemini XI was inextricably linked to the mission’s demonstration of achieving high altitudes. In mid-1965, he learned of plans to fly the spacecraft around the Moon and, even when such a mission was rejected by Jim Webb and Bob Seamans, had pushed vigorously to use some of his Agena fuel to carry Gemini XI into a high orbit. Among the earliest champions of Conrad’s scheme were the scientists – flying to high altitude, he argued, would allow the astronauts to acquire high-resolution imagery of weather patterns and possibly benefit other experiments. Fears that the Van Allen radiation belts might scupper such a mission were allayed when Conrad despatched Anders – a qualified nuclear

Dick Gordon (left) and Pete Conrad demonstrate the tether experiment at their post-flight press conference.

engineer – to Washington to devise and argue ways of avoiding them. Indeed, radiation data gathered by Young and Collins on Gemini X had turned out to be barely a tenth of pre-flight estimates.

The plan to fly Gemini XI to high altitude thus approved, another of its key objectives – tethering the spacecraft to its Agena as a means of demonstrating better station-keeping – bore fruit. Under direction from NASA, McDonnell engineers recommended that a nylon or Dacron line no longer than about 50 m could produce a reasonable amount of cable tension. The station-keeping requirement for such an experiment quickly expanded, however, to encompass a means of inducing a form of artificial gravity. Ultimately, a 30 m Dacron tether was chosen for the task and the only serious concern was how Gemini XI could be freed from the Agena. It was decided to fire a pyrotechnic charge and, failing that, to snap a break line in the tether with a small separation velocity.

Particularly worrisome, though, was achieving rendezvous with the Agena on Conrad and Gordon’s very first orbital pass. (Within NASA, it was known as an ‘M = 1’ rendezvous.) This had been suggested several years earlier by Richard Carley of the Gemini Project Office, in response to Apollo managers’ concerns that such practice was necessary to provide a close approximation of lunar orbit rendezvous. During Gemini X, John Young had expended so much fuel that it seemed overly ambitious, but Flight Director Glynn Lunney eventually appeased naysayers that Mission Control could provide enough backup data on orbital insertion and manoeuvring accuracy that Conrad and Gordon would have all they needed to perform it. Still sceptical, William Schneider, deputy director for Mission Operations, bet the review board’s chairman James Elms a dollar that a first-orbit rendezvous could not be done economically.

Despite the greater success of Mike Collins in performing his EVAs on Gemini X, concerns remained. Practicing spacewalking techniques in a realistic environment had led, in mid-1966, to the adoption of‘neutral buoyancy’ – submerging fully-suited astronauts in a water tank – as the closest terrestrial analogue to the real thing. In his autobiography, Collins related its introduction in the closing weeks before his own mission, but had little time to spare practicing under such conditions. Gene Cernan, perhaps best-placed to observe the difficulties of EVA, was one of the first to undergo neutral buoyancy training, and found that it did indeed approximate his efforts in space.

Yet refining techniques also encompassed an astronaut’s body positioning and the inclusion of more practical aids, including handholds, shorter umbilicals (Young and Collins recommended a 9 m tether, rather than l5 m, to avoid entanglement, which was accepted) and better foot restraints in the Gemini adaptor section. This last proposal led to two suggestions from McDonnell – a spring clamp, like a pair of skis, and a ‘bucket’ type restraint – with NASA finally opting for the latter, which came to be nicknamed the ‘golden slippers’.

Rendezvous, docking, tethered station-keeping and spacewalking. . . and a full plate of 12 scientific experiments would thus fill Conrad and Gordon’s three days in space. Two of the experiments – Earth-Moon libration region imaging (S-29) and dim-light imaging (S-30) – were newcomers to Project Gemini, together with seven already-flown investigations into weather, terrain and airglow photography, radiation and microgravity effects, ion-wake measurements, nuclear emulsions and ultraviolet astronomy and a trio of technical objectives focusing on mass determination, night-image intensification and the evaluation of EVA power tools. By the end of August 1966, the Manned Spacecraft Center had announced that all of the experiments were ready to fly.

Elsewhere, preparations for Gemini XI had become closely entwined with those of the previous mission, Gemini X. The Titan II propellant tank for the latter had become corroded by leaking battery acid during transfer from Martin’s Denver to Baltimore plants in September 1965. It had been replaced with the tank originally allocated to Conrad and Gordon’s flight; the Gemini XI crew were correspondingly assigned the propellant tank previously earmarked for Gemini XII. This finally reached Baltimore for checkout and integration in January 1966.

Six months later, Conrad and Gordon’s Titan was in place on Pad 19 at Cape Kennedy. At around the same time, the Gemini spacecraft itself was hoisted into position and the hot weeks of August were spent connecting cabling and replacing some leaking fuel cell sections.

By this stage, Gemini XI’s launch date had slipped by two days to 9 September, but as the fuelling of its Titan II booster progressed, a minute leak was found in the first-stage oxidiser tank. Technicians quickly set to work rectifying the problem: a sodium silicate solution and aluminium patching plugged the leak and launch was rescheduled for the following day. That attempt, too, came to nothing, as Conrad and Gordon were en-route to Pad 19, when it was learned that their Agena-XI’s Atlas booster was experiencing problems with its autopilot. Hoping to resolve the glitch in time, the General Dynamics test conductor called a hold in the countdown to check it out.

The Atlas engineers out at Pad 14 reported that they were receiving faulty readings and were in the process of running checks to determine if the autopilot component needed replacement. Ultimately, the checks took too long to meet the launch window on 10 September and, after an hour of troubleshooting, the attempt to launch the two vehicles that day was called off. Another attempt, William Schneider announced, would be made on the 12th. It later became clear that the fault was caused by a fluttering valve, coupled with unusually high winds and an over­sensitive telemetry recorder. Fortunately, none of the Atlas’ components needed to be changed and managers cleared the mission to fly.

Early on 12 September, Conrad and Gordon were sealed inside their spacecraft by Guenter Wendt’s closeout team at Pad 19. Despite a minor oxygen leak which required the reopening and resealing of Conrad’s hatch, the launch of their Agena – XI target went ahead on time at 8:05 am. Still, there was little time to waste, for Gemini XI had been granted barely two seconds in which to launch; its almost – impossibly-short ‘window’ dictated by the requirement to rendezvous with the Agena on the astronauts’ first orbit. It demonstrated, if nothing else, the growing maturity of America’s space effort. “Rocketeers of the Forties, Fifties and early Sixties,’’ wrote Barton Hacker and James Grimwood, ‘‘would have been aghast at the idea of having to launch within two ticks of the clock.’’

Aghast or not, Conrad and Gordon’s liftoff was perfect, coming at 9:42:26.5 am, just half a second into its mandated two-second launch period. Six minutes later, on the fringes of space, the two astronauts received the welcome news from Mission Control: their ascent and the performance of their Titan II had been ‘right on the money’ and they were cleared for their M = 1 rendezvous. To kick off its first sequence, just 23 minutes after launch, Conrad pulsed Gemini XI’s thrusters in a so – called ‘insertion-velocity-adjust-routine’ – or ‘Ivar’ – manoeuvre, correcting their orbital path and placing them on track to ‘catch’ the Agena, then 430 km away.

Conrad’s next manoeuvre was more tricky, occurring as it did outside of telemetry and communications range. At the appointed moment, he performed an out-of­plane manoeuvre of about one metre per second, then pitched Gemini XI’s nose 32 degrees ‘up’ from his horizontal flight plane. This completed, the two men activated their rendezvous radar and … just as predicted, they received an immediate electronic ‘lock-on’ with the Agena. By the time they re-established radio contact with the ground, they were just 93 km from their quarry.

Capcom John Young, seated at his console in Houston, sent final numbers through the Tananarive tracking station to the astronauts and, as Gemini XI neared the apogee of its first orbit, Conrad ignited the OAMS to produce ‘multi-directional’ changes – forward, ‘down’ and to the right – in support of the rendezvous’ terminal stage. All at once, less than 40 km away, the Agena flashed into view with orbital sunrise over the Pacific Ocean, almost blinding them as it did so. The two men scrambled for sunglasses and Conrad pulled his spacecraft to within 15 m of the target. Making landfall over California, and a little more than 85 minutes since launch, they had achieved the world’s quickest orbital rendezvous. Moreover, they still retained some 56 per cent of their fuel reserves. William Schneider lost his bet with James Elms, writing that ‘‘I never lost a better dollar’’.

‘‘Mr Kraft,’’ the jubilant astronauts called to Flight Director Chris Kraft, ‘‘would [you] believe M equals 1?’’ On 12 September 1966, he certainly did.

With predictable ambiguity, in the dying months of 1968, the Soviets gave little away to either confirm or deny that they had any interest in competing with the United States to reach the Moon. Fortunately for them, their head of state had not committed them to the same audacious goal as John Kennedy had done for America seven years before. However, it is well known that the Soviets had a vigorous manned lunar effort. . . and made equally vigorous attempts to hide it, although the intricacies will be discussed further in the next volume. On 14 October, indeed, Academician Leonid Sedov told the 19th Congress of the International Astro – nautical Federation in New York that “the question of sending astronauts to the Moon at this time is not an item on our agenda… it is not a priority’’. A few weeks later, discussing Beregovoi’s mission with the press, Mstislav Keldysh was forced to admit that Soyuz was not designed for a circumlunar flight and that journeys to the Moon were not being studied.

For months, though, speculation had grown over the development of a large lunar rocket, known as the ‘N-l’, or, had it successfully flown, as the ‘Raskat’ (‘Peal’). NASA Administrator Jim Webb, informed by CIA sources early in 1968 about the N-l, had proven so vocal about its existence that the booster was also colloquially known as ‘Webb’s Giant’. Its development had begun under Sergei Korolev in 1959 and it was originally intended to lift space stations into orbit or even deliver human crews to Mars with a nuclear-powered upper stage. Two years later, it received a small amount of funding and a government report established a schedule for its maiden launch sometime in 1965. The chance of the N-l moving from paper to production took a dramatic turn with Kennedy’s lunar speech in May 1961 and Korolev began laying plans for a Soviet mission to the Moon, featuring a new spacecraft called ‘Soyuz’.

Several launches, it was realised, would be needed to loft the crew-carrying Soyuz, the lunar lander and additional engines and fuel. Powering the giant rocket would be a new engine known as the RD-270, built by Valentin Glushko, employing unsymmetrical dimethyl hydrazine and an oxidiser of nitrogen tetroxide; this hypergolic mixture reduced the need for a complex combustion system, but also yielded a reduced thrust when compared to a combination of, for example, kerosene and liquid oxygen. Korolev felt that a high-performance design demanded high – performance fuels and moved instead to work with Nikolai Kuznetsov’s OKB-276 bureau, which suggested a ‘ring’ of NK-15 engines on the rocket’s first stage. The interior of the ring would be open, with air piped into the hole through inlets near the top of the stage; this would then be mixed with the exhaust to augment the N-l’s total thrust.

Eventually, in recognition of the difficulties of orbital rendezvous, Korolev opted for a direct-ascent means of reaching the Moon. The result was that the N-l increased dramatically in size and was combined with a new lunar package called the ‘L-3’, which contained additional engines, an adapted Soyuz spacecraft (known as the ‘Lunniy Orbitny Korabl’ or ‘LOK’) and a lunar lander. Had the N-l actually flown successfully, it would have been one of the largest launch vehicles ever built: at 105 m tall, it was slightly shorter than the Saturn V, yet produced a million kilograms more thrust from its first stage engines. It had five stages in total, three to boost it into orbit and two to support lunar activities. The lower three stages formed a truncated cone, some l0 m wide at the base, arranged to best accommodate the kerosene and liquid oxygen tanks.

Astonishingly, the first stage – known as ‘Block A’ – was powered by no fewer than 30 NK-15 engines, arranged in two rings, with one ring handling pitch and yaw and the others on gimballing mounts for roll manoeuvres. With an estimated thrust of 4.5 million kg, Block A would have easily out-thrust the Saturn V’s first stage, although its use of kerosene offered poorer performance: it could place 86,000 kg into low-Earth orbit, compared to the Saturn V’s 118,000 kg. The N-l’s second stage would have comprised eight uprated NK-15V engines in a single ring and four smaller NK-21 engines in a square arrangement on its third stage.

The complexities of building plumbing to feed fuel and oxidiser into the clustered rocket engines proved an incredibly delicate and fragile task and contributed in part to the four catastrophic N-1 launch failures between 1969-72. The plumbing difficulties experienced during the construction of the Saturn V’s first stage, which comprised just five engines, must have been exacerbated tenfold for the N-1’s 30 engines. During the week that Apollo 8 circled the Moon, the first N-1 was being readied at Tyuratam for its first unmanned launch, scheduled for early in 1969.

As the N-1 proceeded through its torturous and ultimately unsuccessful development process, another rocket – the Proton – was meeting with greater success. It had been designed to loft a cosmonaut-carrying version of the Soyuz spacecraft, albeit without an orbital module, on a circumlunar trajectory. In readiness for this so-called ‘Soyuz 7K-L1’ variant, a number of unmanned missions were launched towards the Moon under the cover name of ‘Zond’. Despite several dismal Proton failures, Zond 5 was launched on 14 September 1968, passing within 1,950 km of the lunar surface and splashing down in the Indian Ocean seven days later. In addition to demonstrating the spacecraft which might someday support two cosmonauts, Zond 5 took the first living creatures – a pair of steppe tortoises, wine flies, mealworms, plants, seeds and bacteria – to the vicinity of the Moon.

Eight weeks later, on 10 November, Zond 6 provided perhaps the biggest impetus to get Apollo 8 into lunar orbit before the end of the year, when it too carried a biological payload and numerous instruments to the Moon. It hurtled just 2,420 km past the lunar surface, acquiring high-resolution photographs, but its descent module depressurised during re-entry into Earth’s atmosphere. This killed all of the biological specimens and would probably have resulted in the deaths of cosmonauts, too, had they been aboard. On the other hand, failure occurred because the spacecraft was held in an unusual attitude for a protracted time, owing to a problem that a pilot could have readily been able to overcome. Further, the seal suffered in the heat of the Sun and would not have been overly stressed if a crew had been aboard. To add insult to what had been a less-than-successful mission, only one negative was recovered from its camera container. . . and its parachutes deployed too early, causing it to crash land. Despite the depressurisation and parachute faults, either of which would have doomed a human crew, Tass’ announcement a few days later explicitly stated that Zond 6’s mission had been “to perfect the flight and construction of an automated variation of the manned spacecraft for flying to the Moon’’. It marked a stark contrast to Sedov’s claim only weeks earlier that the Soviets had no interest in manned lunar missions. . .

In perhaps one of the bitterest ironies, Frank Borman, who would command Apollo 8, the first manned circumlunar expedition, became the first American astronaut to be invited to the Soviet Union afterwards. When he arrived, he was welcomed with a huge party, held in his honour at Moscow’s Metropole Restaurant. Hundreds of guests flocked to shake his hand and have their photograph taken with him. One of them was Alexei Leonov. Borman congratulated Leonov on his Voskhod 2 spacewalk and the two chatted about the circumlunar mission and possible landing sites on the Moon. Most likely, Borman considered Leonov to be showing the interest typical of a space explorer. Little did he realise that Leonov had been training to complete the very same goal for which Borman was now being applauded.

Initially, in the months after Sergei Korolev’s death, Leonov and a civilian cosmonaut, possibly Oleg Makarov, had been tipped to fly the first circumlunar Soyuz mission sometime in the summer of 1967. “We then expected to be able to accomplish the first Moon landing,’’ wrote Leonov, “ahead of the Americans in September 1968.’’ The Soviet plan was for one cosmonaut to descend to the surface in the LK (‘Lunniy Korabl’) landing craft, whose spidery appearance was uncannily similar to Grumman’s lunar module, leaving his colleague in orbit aboard the main L-3 craft.

‘‘To train for the extreme difficulties of a lunar landing,’’ Leonov wrote, ‘‘we undertook exhaustive practice in modified Mi-4 helicopters. The flight plan of a lunar landing mission called for the landing module to separate from the main spacecraft at a very precise point in lunar orbit and then descend towards the surface of the Moon until it reached a height of 110 m from the surface, where it would hover until a safe landing area could be identified. The cosmonaut would then assume manual control of its descent. . . ’’ In addition to flying the circumlunar mission, it is likely that Leonov would have hoped for such a landing mission of his own. For that reason, he qualified as a helicopter pilot and spent much of 1966 and 1967 using it to prepare himself as much as possible for a Moon landing.

Not only would the journey to the lunar surface be fraught with risk, but so too would the return to Earth. In fact, the Soviet plan to slow down from transearth velocities would be to enter the atmosphere, ‘bounce’ off and re-enter a second time,

as would Apollo. “The key to this difficult manoeuvre,” continued Leonov, “was the angle of re-entry. If it was wrong, the spacecraft would be severely deformed, perhaps even destroyed… Several times during training sessions, I sustained pressures of 14 G, the maximum to which a human being can be subjected on Earth. This put tremendous strains on every cell in my body and caused several haemorrhages at those points where my body was most severely compressed.” With the completion of Zond 6, western analysts knew that the next favourable ‘window’ for a Soviet circumlunar shot opened on 6 December 1968, just two weeks before the window for Apollo 8. It never happened. The parachute failure and the depressurisation issue were sufficiently serious to have killed a cosmonaut crew and Vasili Mishin did not want to risk one until Zond was proven by at least two further test flights. Of course, the Americans knew nothing of this and missing the December window would pose yet more questions as to what the Soviets were up to. Years later, Alexei Leonov would tell Tom Stafford that he and Oleg Makarov were prepared to take the risk and ride a Zond for seven days to the Moon and back. ‘‘We could have beaten the Apollo 8 crew,’’ Leonov said sadly, ‘‘but Mishin was a blockhead.’’

It is July 1966. At Cape Canaveral Air Force Station in Florida, a 41-year-old test pilot named Jim Wood is moments away from becoming the United States’ 17th man in space. Alone, pressure-suited and tightly strapped into the tiny cockpit of a stubby winged ship called ‘Dyna-Soar’, he will shortly be boosted by a Titan III-C rocket onto a suborbital trajectory to evaluate the world’s first reusable manned spacecraft. It was a precocious forerunner of the Space Shuttle and, indeed, had it flown, many observers believe that it could have revolutionised – perhaps even ‘routinised’ – today’s space travel.

Wood’s mission never happened. Nor did Dyna-Soar itself reach fruition, although at the time of its cancellation in December 1963 it was supposedly eight months away from performing a series of airborne drop-tests from a modified B-52 bomber. Much criticism has been levelled at then-Secretary of Defense Robert McNamara, accusing him of poor judgement in killing a project with so much promise, so close to completion and whose contractors had already spent nearly half of its $530 million development budget. To be fair, Dyna-Soar faced immense problems of its own, the most important of which was its ill-defined purpose.

The spacecraft was viewed from two different perspectives during its genesis in the late Fifties: as a research vehicle to explore hypersonic flight regimes or, as the Air Force preferred, as a fully functional military glider capable of delivering live warheads with precise, pilot-guided accuracy onto targets anywhere on Earth. Ambitious plans were even afoot for the inspection and maybe destruction of enemy satellites in orbit, as well as the carriage of reconnaissance cameras, side-looking radar and electronic intelligence sensors. Assuming a manned flight sometime in the summer of 1966, it was hoped that Dyna-Soar would evolve into this advanced weapons system by the mid-Seventies. This would offer military strategists a route around the problem that ‘conventional’ ballistic missiles might no longer be able to strike hardened targets with sufficient accuracy. Moreover, the ‘boost-glide’ flight profile of Dyna-Soar – able to cover velocities between Mach 5 and 25 – was perceived as a better alternative to using complex, air-breathing turbojet or ramjet engines, which were difficult to develop and could only operate a lower speeds. Indeed, according to studies conducted by the Rand Corporation, vehicles flying below Mach 9 might be rendered vulnerable to Soviet air defences by 1965.

In the most paranoid days of the Cold War, Dyna-Soar thus provided the United States with a seemingly invincible means of attacking and snooping on enemy targets from any direction and, when flying at low altitudes, gave barely a three-minute warning of its arrival. Additionally, it could sweep across Soviet territory at altitudes in the range of 40 to 80 km, providing a much better imaging resolution than was possible with the best spy satellites and its data could be in the hands of Pentagon officials within hours.

Size-wise, this astonishing machine was a third as large as today’s Shuttle: 10.6 m long, with a wingspan of 6 m. Powered by a Martin-built ‘trans-stage’ engine, capable of 32,660 kg of thrust, it would have ridden into space atop the Titan III-C. This choice of launch vehicle changed significantly as Dyna-Soar’s own purpose fluctuated. ‘‘It was originally scheduled to be launched on the Titan I,’’ said Neil Armstrong, one of its original pilots, ‘‘[then] when the Titan III was introduced, with additional [solid] rocket engines strapped on the side, it [became] an orbital vehicle.’’ Armstrong left the project in mid-1962 to join NASA’s astronaut corps and later revealed that Dyna-Soar’s main aim was for hypersonic research, hence its acronym: the ‘dynamic soarer’. Its 72.48-degree delta wings were flat-bottomed and its aft fuselage was ‘ramped’ to give directional stability at transonic speeds. This would have provided a sufficient hypersonic lift-to-drag ratio to permit a cross-range capability of around 3,200 km. In other words, a diverted landing from Edwards Air Force Base in California meant that it could conceivably touch down anywhere in the continental United States, Japan or even Ecuador.

In fact, thanks to a unique set of wire-brush ‘skids’, it could even land on compacted-earth runways little more than 1.6 km long. Typically, it would have been launched from Cape Canaveral by the Titan III-C, then remained affixed to the rocket’s third and final stage. This would have acted as a restartable ‘trans-stage’, capable not only of inserting Dyna-Soar into a 145 km orbit, but also adjusting its altitude and inclination. The trans-stage could boost its velocity, thus frustrating ground-based efforts to predict its overflight path during bombing or spying missions.

Emergency aborts during a Dyna-Soar launch, though, did not fill Armstrong with confidence. ‘‘There was a question [of] what kind of abort technique would be practical to try to use in case there was a problem with the Titan,’’ he recalled years later. ‘‘It was determined, rather than a ‘puller’ rocket, [we had a] ‘pusher’ rocket to push the spacecraft up to flying speed from which it could make a landing, but it wasn’t known at that time what might be practical, how much thrust would be needed and how much performance would be needed. We had the F-5D aircraft, which I determined could be configured to have a similar glide angle for the Dyna – Soar for similar flight conditions and devise a way of flying the aircraft to the point at which the pusher escape rocket would burn out, so you would start with the identical flight conditions that the Dyna-Soar would find itself after a rocket abort from the launch pad. Then, you only had to work out a way to find your way to the runway and make a successful landing. I worked on that project for a time and found a technique that would allow us to launch from the pad at Cape Canaveral and make a landing on the skid strip. We practiced that and I believe that [NASA test pilots] Bill Dana and Milt Thompson both continued after I transferred from Edwards to Houston. There was a NASA report written about the technique. It was a practical method. I wouldn’t like to have to really do it in a real Dyna-Soar!’’

During its development, the Air Force also hoped to conduct synergistic exercises in which the spacecraft could dip into the upper atmosphere, employ its aerodynamic manoeuverability to change its inclination relative to the equator and refire the trans-stage to boost itself back into orbit. This tricky task was provisionally pencilled-in for the fifth manned test, sometime in the spring of 1967, after which pilots would have begun evaluating its precision-landing capabilities. In the event of trans-stage problems, a solid-fuelled abort motor, derived from the Minuteman missile, was attached to Dyna-Soar and would have separated the pair, performed an emergency retrofire and initiated re-entry. On the other hand, assuming a successful mission had been completed, the trans-stage would have been jettisoned over the Indian Ocean and the spacecraft would commence its long glide through the atmosphere to touch down at Edwards. Later missions, intended to complete two or even three Earth orbits, were expected to fly at higher altitudes of around 180 km. During re-entry, the pilots would test Dyna-Soar’s controllability at various pitch angles during a range of hypersonic and thermal flight regimes.

It was not, however, completely controllable by its pilot throughout the entire speed range and a fly-by-wire augmentation system was provided to run in four automatic modes. A side-arm controller offered him the ability to perform pitch and roll inputs and, through conventional pedals, to execute yaw manoeuvres; the Titan III-C would even have been able to be flown manually during part of its initial boost in orbit! Throughout re-entry, the guidance computer – capable of storing up to ten airfield locations – would have provided continuous updates on Dyna-Soar’s display to advise on issues such as angle-of-attack, banking angles and structural limitations.

Physically, the spacecraft was based on a Rene 41 steel truss, which compensated for thermal expansion within the heated airframe during re-entry. Dyna-Soar was roughly divided into four parts: a pilot’s cockpit, pressurised central section and two unpressurised equipment bays. Each internal compartment was encased in a ‘water wall’ to offer passive cooling during re-entry, allowing their pressure shells to be constructed from conventional aluminium. Additional cooling within each compartment brought temperatures down still further to around 46°C.

In order to withstand the fiery plunge into the atmosphere, Dyna-Soar’s belly and wing leading edges were coated with molybdenum and its nosecap tipped with zirconium. Theoretical predictions expected the wing edges to reach temperatures of 1,550°C, the nosecap around 2,000°C and the belly some 1,340°C during the most extreme re-entry profiles. During all flight phases, the pilot had clear views through two side windows, but the three-piece forward windshield was covered during ascent, orbital operations and most of re-entry. Interestingly, the cover – which guarded against thermal extremes – was not scheduled to be blown off until Dyna-Soar reached a speed of Mach 6, just in time for landing. Tests conducted by Neil Armstrong in the modified Stingray fighter, however, showed that, in the dire eventuality that the cover failed to jettison properly, landings could be safely performed using only the two side windows for visibility. Clearly, this was far from ideal and stands testament to the skills of the men chosen to fly Dyna-Soar: Wood, Armstrong, William ‘Pete’ Knight, Milt Thompson, Al Crews, Hank Gordon and Russ Rogers.

The cockpit in which the pilot would have sat provided all the instrumentation and life-support gear to fly the vehicle, together with an ejection seat which could only be used at subsonic speeds. Behind the cockpit, the central section – pressurised with 100 per cent nitrogen – would have carried a 450 kg instrumentation package, fitted with data recorders for more than 750 temperature, pressure, loads, systems performance, pilot biometrics and heat flux sensors. Finally, at the rear of Dyna – Soar were the equipment bays, containing liquid hydrogen and nitrogen supplies, hydrogen peroxide tanks and power system controls.

The leading contenders for building the spacecraft in the late Fifties were Bell and Boeing, both of which offered the capability to cover the entire requirement range from low-Mach speeds to orbital velocity using a single vehicle. Ultimately, despite Bell’s expertise in designing winged spacecraft of this type, Boeing was chosen as Dyna-Soar’s prime contractor in June 1959. Original plans called for three ‘waves’ of operations: a series of suborbital flight tests, followed by orbital and eventually operational weapons-delivery missions. By the autumn of 1962, critical design reviews of Dyna-Soar’s subsystems had been completed and significant break­throughs achieved in high-temperature materials and fabrication of components for the ‘real’ airframe. Publicly, it seemed worth the wait. When a mockup of the spacecraft was displayed at Las Vegas in September of that year, it quickly grabbed the imagination of America. Writing in Reader’s Digest after the event, John Hubbel

described it as looking “like a cross between a porpoise and a manta ray” and enthused that Dyna-Soar was one of the most important aviation triumphs since the Wright Brothers’ first flight.

Many others agreed with him. The Mercury capsules were blunt and uninspiring in comparison to this sleek, futuristic spaceplane. Despite the public adoration of Dyna-Soar, however, the project was in serious trouble and barely months away from cancellation. Robert McNamara had already expressed serious concerns that it lacked direction or specific purpose – the Department of Defense regarded it as a hypersonic research vehicle, the Air Force as a strategic bomber – and very little attention had been paid to precisely what missions it would undertake. McNamara made his opinions clear during a series of reviews of the project during the course of 1963, before ultimately cancelling it at year’s end in favour of a military space station called the Manned Orbiting Laboratory. Ultimately that, too, wasted millions of dollars and never bore fruit.

More than four decades later, Dyna-Soar is recognised as an ambitious, far­sighted endeavour, literally at the cutting-edge of the technology of its day. Its legacy remains visible in many elements of the Shuttle’s design and capabilities – from the concept of the ‘rocket-glider’ to the payload bay, from landing on pre-determined runways to its reusability – and its extensive wind-tunnel testing provided valuable engineering data for later projects. In the words of a recent NASA study of the X – planes, of which Dyna-Soar was one, ‘‘very few vehicles have contributed more to the science of high-speed flight – especially vehicles that were never built!’’

Amidst such euphoria, Conrad’s actual docking with Agena-XI at 11:16 am seemed anticlimatic, although both astronauts were able to practice the docking-and – undocking exercise which had eluded John Young two months earlier. Pulling loose from the target, then redocking, said Conrad, was much easier in space than on the ground and the astronauts managed it in daylight and darkness. It also gave Dick Gordon the distinction of becoming the first astronaut not in a command position to perform a docking manoeuvre.

This was followed by an ignition of the Agena’s main engine to boost their orbital altitude to the highest yet achieved by humans. Facing 90 degrees away from the flight path, Conrad fired the engine to add 33 m/sec to their velocity, as a test-run, and confirmed to Young that this was ‘‘the biggest thrill we’ve had all day’’. It was but the prelude for one of their main tasks on 14 September: increasing the high point of their orbit to no less than 1,370 km. For now, however, the astronauts rested, powering down Gemini XI, tucking into their first meal and bedding down for their first night’s sleep in space.

Despite its audacious nature, their only problem was a pair of dirty windows. This had, in fact, plagued each Gemini to date and even covers which could be jettisoned after launch had been little help. Capcom Al Bean told Gordon to rub half of Conrad’s window with a dry cloth during his spacewalk on 13 September. Four hours before they were scheduled to open Gemini XI’s hatch, they began preparing their suits and equipment; only to realise that, so thorough was their training, they actually needed barely 50 minutes to have all of their gear up and running.

By this point, Gordon could conceivably have gone outside, so Conrad called a halt, which left them sitting idly, fully kitted-out in their equipment. An hour later, they hooked up Gordon’s environmental support system and conducted several oxygen-flow checks, which proved a mistake because it dumped oxygen into the cabin and its excess was then vented into space. They could ill-afford this rate of oxygen loss and Conrad told Gordon to switch back to Gemini XI’s systems. Gordon, by this point uncomfortably warm, was relieved to get back onto the interior environmental control system. After all, the extravehicular system’s heat exchanger had been designed to operate in a vacuum, rather than inside a pressurised cabin.

The main problem, wrote astronaut Buzz Aldrin, actually lay in Conrad and Gordon’s impatience in skipping through the formal, six-page, hundred-plus-step sequence of donning and preparing their equipment. “As a result,’’ Aldrin related in 1989, “they upset cabin pressurisation when they checked out Gordon’s oxygen umbilical and he became overheated long before his EVA began.’’

The men considered asking Flight Director Cliff Charlesworth to let Gordon begin his EVA one orbit early, but due to issues with tracking and lighting, decided to stick with the pre-planned schedule, a decision that they would come to regret. As they prepared to fit Gordon’s sun visor onto his helmet, it proved a stubborn chore; Conrad eventually fastened one side, but could not reach over to snap the other side in place, leaving Gordon hot, bothered and in need of rest. After struggling for a few more minutes, Gordon eventually snapped the right side in place – cracking the sun visor in the process – and was thoroughly winded by the time he cranked open the hatch and stood on his seat at 9:44 am on 13 September, just two minutes past one full day into the mission. . . and precisely on time.

Instantly, Gordon’s exit into space was accompanied by everything else inside the cabin that was not tied down. Standing on his seat, his first activity was to deploy a handrail – a fairly easy task – after which he removed the S-9 nuclear emulsion package from outside the spacecraft and passed it in to Conrad, who stuffed it into his footwell. Next, Gordon tried to install a camera in a bracket to photograph his own movements, but this proved difficult. To resolve it, Conrad let enough of the umbilical slide through his gloved hand to let Gordon float above the camera, thump it with his fist and secure it in place.

The spacewalker’s next task was to attach the 30 m Dacron tether, housed in Agena-XI’s docking collar, onto Gemini XI’s nose. As Gordon pushed himself forward, he missed his goal and drifted in an arcing path above the adaptor and around in a semi-circle, until he reached the back of the spacecraft. However, Conrad had released only a couple of metres of the 9 m umbilical, so he pulled Gordon back to the hatch to start his trek again.

At length, Gordon reached the target and grabbed some handrails to pull himself astride Gemini’s nose – prompting Conrad to yell “Ride ‘em, cowboy!” – but the exercise proved more difficult in space than it had in ground tests. Aboard the zero – G aircraft, Gordon had been able to push himself forward, straddle the Gemini’s re­entry and recovery section and wedge his feet and legs between the docking adaptor and the spacecraft to hold himself in place, thus leaving his hands free to attach the tether and clamp it to the docking bar. However, in the vacuum of space, he found himself constantly fighting against his suit to keep himself from floating away; a situation rendered all the more difficult by the lack of any kind of ‘saddle’ or ‘stirrup’ to help him. All Gordon could do was hold on with one hand and try to operate the tether clamp with the other.

He struggled vigorously for six minutes, finally securing the line and setting the stage, at last, for the tethered flight experiment which would come later in the mission. Yet it was clear to Conrad that Gordon was encountering severe difficulties and the differences between EVA practice in terrestrial conditions and the real thing were profound: the spacewalker, soaked with sweat and eyes stinging, was reduced to groping his way blindly around. He tried to remove a mirror on Gemini XI’s docking adaptor, to help Conrad see him at the back of the spacecraft, but it would not move, and had no chance to wipe the windows either.

As Gordon neared the hatch, Conrad helped as much as he could, discussing procedures for getting to the spacecraft adaptor to store his zip-gun. It was obvious, though, that Gordon was exhausted: when they passed next over the Tananarive tracking station, Conrad told John Young that he had ‘‘brought Dick back in… he got so hot and sweaty, he couldn’t see’’. Unlike Gene Cernan, however, Gordon had no trouble whatsoever getting back inside Gemini XI or closing the hatch. Disappointingly, the spacewalk had lasted just 33 of its intended 107 minutes and one of its key tasks – experiment D-16, a power tool evaluation which had also evaded Dave Scott on Gemini VIII – was lost. Clearly, many of the complexities of EVA still remained to be resolved.

Having said that, Gordon’s exhaustion did not disrupt the remainder of the mission. Flight planners had learned to schedule periods of less-vigorous activity immediately after heavy workloads and Conrad and Gordon’s next task involved leisurely repacking equipment and restoring some semblance of order to the cabin. Additionally, communications with Mission Control dwindled to little more than short transmissions about spacecraft systems and medical checks, which gave them much-needed respite. Conrad test-fired a sluggish thruster, the men ate a meal and photographed the atmospheric airglow.

These moments of relatively quiet time would not last. Ahead of them lay the so – called ‘high ride’ – their Agena-assisted climb to a record-breaking altitude of 1,370 km. To prepare themselves, they donned their suits, closed their visors and secured as much cabin equipment as possible, as if in readiness for re-entry, and focused their attention on the Agena-XI. A problem quickly appeared. As they made a pre-firing

check of the target, it became clear that it was not properly accepting commands; instructions, in fact, had to be transmitted twice before they were acknowledged. Conrad expressed his concerns to Capcom Al Bean, who told them that, in fact, the Agena was responding correctly, but Gemini XI’s displays were at fault. “Heck of a time to have a… glitch like that show up,’’ Conrad grumbled, but was assured that everything remained ‘go’ for the burn.

Forty hours and 30 minutes after Gemini XI’s launch, at 2:12 am on 14 September, Conrad fired the Agena’s engine for 26 seconds, adding a blistering 279.6 m/sec to their speed. Both men were electrified by the burn. ‘‘Whoop-de-doo!’’ Conrad yelled. ‘‘[That’s] the biggest thrill of my life!’’ Like the experience of John Young and Mike Collins two months earlier, Conrad and Gordon were pushed ‘forward’ against their seat harnesses and, gradually, saw the Earth change from a vast expanse of blue and white beneath them. . . into something more planet-like, with a very distinct curvature. ‘‘I’ll tell you,’’ Conrad told the capcom in Carnarvon, Australia, ‘‘it’s go up here and the world’s round. . . you can’t believe it. . . I can see all the way from the end, around the top… about 150 degrees.’’

Beneath them, Conrad told Al Bean, the men beheld the intense and striking blues of the oceans, the sprinkling of clouds and the astonishing clarity of Africa, India and Australia. ‘‘Looking straight down,’’ he radioed, ‘‘you can see just as clearly. There’s no loss of colour and details are extremely good.’’ To cope with the adverse radiation effects of the Van Allen belts, Gemini XI’s high-apogee orbits were timed to take place over Australia, where levels were calculated to be relatively low. Over Carnarvon, indeed, Conrad reported that on-board dosimeters read barely 0.2 rads per hour. ‘‘Sounds like it’s safer up there than a chest X-ray,’’ replied Bean. In fact, Conrad added, Gemini XI experienced less radiation at 1,370 km than Young and Collins had endured in a longer period of time at 830 km.

It was at this altitude – 1,370 km high, the highest yet attained by humanity – that the flight’s imaging experiments, notably the synoptic terrain and weather photography objectives, produced some of their most stunning results. In total, Conrad and Gordon clicked more than 300 exposures and their descriptions of the sheer clarity of the eastern hemisphere filled principal investigators with excitement and anticipation.

Not until Apollo 8’s journey to the Moon in December 1968 would humans travel to higher altitudes and four decades later, Conrad and Gordon retain the record for the highest-ever Earth orbit attained by humans. ‘‘As the coupled craft soar toward their record apogee,’’ Time magazine told its readers a week after Gemini XI’s splashdown, following NASA’s release of the pictures, ‘‘the curvature of the Earth’s horizon becomes more pronounced and the Earth assumes an unmistakably globelike shape. Though the pictures are sharp and show geological features plainly, the Earth seems devoid of life; it offers no visible evidence of its teeming population, its great cities, its bridges or its dams.’’

Two orbits later, on their 26th revolution, as Gemini XI passed over the United States, Conrad again fired the Agena’s engine for 23 seconds to lower their apogee to 304 km and reduce their speed by 280 m/sec. After a bite to eat, at 8:49 am, Gordon opened his hatch, high above Madagascar, for his second EVA. This time, he stood

Dick Gordon, photographed by Pete Conrad shortly before opening Gemini XI’s hatch to throw out unwanted equipment.

on the ‘floor’ of Gemini Xf, poked his helmeted head outside and watched the sunset. Secured by a short tether, he could at least use both hands to mount cameras easily in their brackets and remained ‘outside’ for no less than two full hours. ‘‘Most enjoyable’’ was his summary of the stand-up EVA and, indeed, flight surgeons commented that from the biosensor data, it was uneventful.

Whilst outside, Gordon experienced two nighttime passes, photographing several star fields with the S-13 ultraviolet camera and his view was so unimpaired that he was able to coach Conrad about which way to direct Gemini Xf. Although the Agena’s stabilisation proved somewhat erratic, the linked vehicles remained sufficiently stable to yield excellent results in about a third of Gordon’s photographs. fndeed, as the spacecraft passed over the United States, the skies were so clear that both men were able to marvel at the view of Houston. Drifting across Florida, then out over the Atlantic, Gordon suddenly broke the silence to tell Conrad that he had just fallen asleep outside. He was not the only one: Conrad, too, had dozed off inside the spacecraft.

‘‘That’s a first,’’ radioed John Young. ‘‘First time sleeping in a vacuum.’’

Returning inside after two hours and eight minutes, Gordon’s exhaustion was not, like that of Cernan, caused by over-exertion and battling against his rigid suit, but instead by sheer concentration on his tasks.

Their next step was the tethered vehicle exercise, which could be attempted by two different means. One of these assumed the position of a ‘pole’, always pointing towards Earth’s centre – a so-called ‘gravity gradient’ attitude – in which Conrad and Gordon would have backed their spacecraft out of the Agena’s docking cone slowly until the 30 m tether became taut. ff properly positioned, a slight thrust of just 3 cm/sec would have kept the tether taut and the joined ‘pole’ would have drifted serenely around the globe, each spacecraft maintaining the same relative position and attitude.

Should this have been unsuccessful, the men were tasked with trying a ‘spin-up’, or ‘rotating’, mode, a technique studied by McDonnell engineers. fn this case, after physical undocking, Conrad would fire Gemini Xf’s thrusters to induce a rotation of one degree per second and as the tethered pair circled Earth, their mutual centre-of – gravity would lie at a specific point on the tether, around which they would do a slow, continuous cartwheel. Centrifugal force would, it was theorised, keep the tether taut and the two spacecraft apart, with the tether itself providing centripetal force to keep them both in equilibrium.

Over Hawaii, Conrad and Gordon separated from the Agena and began the cautious attempt to start the gravity gradient demonstration. There was enough initial tension in the tether to upset the target and cause the Gemini to move to the ‘right’ – towards the Agena’s docking adaptor – and Conrad quickly adjusted his motion. Then, as he backed away, the tether stuck, probably in the stowage container, when just 15m had been released. Conrad pulsed the OAMS thrusters to free the tether, but it quickly became hung up on a patch of Velcro and he was forced to shift Gemini Xf out of vertical alignment to peel the tether off the Velcro pad. This disturbed the Agena again and there still remained about 3 m of tether to be pulled out.

On the ground, engineers began to worry. The Agena should have taken around seven minutes to stabilise itself; when it took longer, they began to suspect that something was wrong with its attitude-control system and opted to abandon the gravity gradient attempt and adopt the ‘spin-up’ mode instead. However, when Conrad tried to initiate the rotation, another problem arose when he could not get the tether taut; it seemed to rotate counter-clockwise. ‘‘This tether’s doing something I never thought it would do,’’ he told John Young. ‘‘It’s like the Agena and I have a skip rope between us and it’s rotating and making a big loop… Man, have we got a weird phenomenon going on here!’’

Although the spinning line was curved, it also had tension, and for several minutes Conrad and Gordon jockeyed Gemini XI’s thrusters to straighten the arc. Eventually, the tether straightened and became taut and Conrad rolled the spacecraft and fired the thrusters to begin the slow cartwheeling motion. At first, it seemed that he had ‘stretched’ the tether, which had a big loop in it, but steadily, as both astronauts gritted their teeth, centrifugal force took over and it smoothed out. A 38- degree-per-minute rotation rate was obtained and remained steady throughout a nightside orbital pass.

Moving into dawn, they were asked by the Hawaii capcom to accelerate their spin-up rate and, with some reluctance, Conrad agreed. Suddenly, Gordon shouted ‘‘Oh, look at the slack! It’s going to jerk this thing to heck!’’ When the added acceleration started, the tether tightened, then relaxed, causing a ‘slingshot’ effect which seesawed both astronauts up to 60 degrees in pitch. In response, Conrad steadied the spacecraft and, to his surprise, the Agena stabilised itself. Their rotation rate checked out at 55 degrees per minute and they were able to test for a tiny amount of artificial gravity: when they placed a camera against Gemini XI’s instrument panel and let go, it moved in a straight line to the rear of the cockpit and parallel to the direction of the tether. Neither of the astronauts, however, felt any physiological effect of gravity. After three hours of docked operations, they jettisoned Gemini XI’s docking bar and pulled away.

Despite understandable disappointment that the gravity gradient technique could not be fully demonstrated, the spin-up mode at least proved that station-keeping could be done economically. After undocking, Conrad originally intended to decrease his spacecraft’s speed, allowing him to pull ahead of the Agena, but was advised instead to prepare for a ‘coincident-orbit’ rendezvous, whereby he would follow the target by 28 km in its exact orbital path. This would demonstrate their ability to station-keep at very long range with little fuel usage.

As a result of the plan change, Gemini XI’s separation manoeuvre was adjusted; instead of a retrograde firing, Conrad and Gordon ‘added’ speed and height to their orbit, such that Agena-XI passed ‘beneath’ and in front of them. Next, they fired their OAMS to place themselves in the same (coincident) orbit as the Agena, trailing it. Three-quarters of a revolution around Earth, Conrad decreased his ‘forward’ speed and, as expected, Gemini XI dropped into the Agena’s orbital lane, 30 km behind it, with no relative velocity between the pair.

At the same time, the men set to work on another of their scientific tasks: the night-image intensification experiment (D-15), which sought to evaluate the usefulness of equipment which scanned ground-based objects onto the instrument panel. Conrad aimed Gemini XI at specific targets, including towns and cities, cloud formations, lightning flashes, horizons and stars, airglow, coastlines and peninsulas, while Gordon described his view on the monitor into a tape recorder. Unfortunately, Conrad’s dirty window prevented him from seeing much and, indeed, the glow from the monitor meant that he never became adequately dark-adapted. Nonetheless, the men returned with astonishing recollections, including the lights of Calcutta, whose shape almost exactly paralleled official maps of the city.

Turning their attention back to the Agena, they asked ground controllers on the Rose Knot Victor tracking ship how far they were from the target and were advised that their distance remained 30 km, closing very slowly. A second rendezvous, beginning at 3:09 am on 15 September, was near-perfect: Conrad tilted Gemini XI’s nose 53 degrees above level flight and fired the forward thrusters. This placed them in a lower orbit than the Agena, ready to catch up with it, and they took some time to tend to their experiments. An hour later, Conrad fired the aft thrusters to raise his spacecraft’s orbit, then began to brake Gemini XI until he finally reported that he was on-station and steady with the target once more. Twelve minutes later, they executed a separation burn from the Agena for the final time. By this stage, the success had been so great that they could afford to be jocular; Conrad even asking Flight Director Glynn Lunney to send up a tanker to refuel them for more rendezvous.

The ambitious mission came to a close with a fully-automatic re-entry; unlike previous returns, in which the command pilots had flown their spacecraft down from 120 km using the Gemini’s offset centre-of-gravity to generate lift for changes in direction, Conrad would not use his hand controller in conjunction with computer directions. Gemini XI would follow computer commands automatically, a technique derisively nicknamed ‘chimp mode’ by the astronauts. Seventy hours and 41 minutes after launch, at 8:24 am on 15 September, partway through their 44th orbit, the retrorockets fired. Conrad disengaged his hand controller and put the system onto autopilot. This performed admirably and Gemini XI splashed down safely, within 4.6 km of the helicopter carrier Guam, at 8:59 am.

Half an hour after hitting the Atlantic, Conrad and Gordon were aboard the Guam, almost exactly three days since leaving Cape Kennedy. Rendezvous, docking and their record-breaking altitude boost had been, all three, successfully achieved; yet EVA issues remained. Buzz Aldrin, in training to conduct his own excursion on Gemini XII in November, became one of the first astronauts to work underwater in ‘neutral buoyancy’ to prepare himself for working in space. His was supposed to be one of the most complex to date, completing what Gene Cernan had been unable to do in June: flying the Air Force’s AMU backpack. Ironically, had the AMU flown on Gemini XII, Aldrin would not, and almost certainly he would not have gone on to become the second man on the Moon.

Since July 1969, Mike Collins has achieved fame as ‘the other one’ on the first lunar landing crew. A year before making that momentous flight, he might have been aboard Frank Borman’s Apollo 9 mission, destined to perform a high-Earth-orbit test of the combined command and service module, complete with the lunar module. That mission changed significantly by the time it finally flew, renamed ‘Apollo 8’, in December 1968. For Collins, though, the most significant change was that he had gone from being the mission’s senior pilot. . . to sitting on the sidelines in Mission Control.

The original line-up for the Apollo lunar effort envisaged a seven-step process, labelled ‘A’ through to ‘G’. First would come unmanned test flights (‘A’) of the command and service module, already achieved by Apollo 4 in November 1967 and Apollo 6 in April 1968. Next, the ‘B’ mission, completed by Apollo 5, would conduct an unmanned test of the lunar module. A manned ‘C’ flight, involving the command and service modules in Earth orbit, was originally assigned to Gus Grissom, but completed by Wally Schirra’s Apollo 7 crew. Final strides towards the Moon focused on four increasingly more complex missions: ‘D’ (a manned demonstration of the entire Apollo system in Earth orbit), ‘E’ (repeating D, albeit in a high elliptical orbit with an apogee of 6,400 km), ‘F’ (a full dress-rehearsal in orbit around the Moon) and ‘G’ (the landing itself).

During the course of 1966, crews were assembled to support the first of these flights. When Wally Schirra removed himself from the original Apollo 2 crew and scuppered the ‘duplicate’ mission, a ‘new’ Apollo 2, destined to complete the D mission, was given to Jim McDivitt, Dave Scott and Rusty Schweickart for the manned lunar module flight in Earth orbit. Years later, Deke Slayton would note that McDivitt had been intimately involved with the lunar module’s development for some considerable time and the rendezvous commitment of the mission necessitated a veteran command module pilot, Dave Scott. The command and service module and lunar module were to be launched on a pair of Saturn 1Bs. The E crew, targeted to fly the Saturn V for the first time on Apollo 3, was named as Frank Borman, Mike Collins and Bill Anders.

Numbering changed in the wake of the Apollo 1 fire, of course, but the crews remained more or less intact. In the months preceding Apollo 7, the McDivitt and Borman crews seemed on track to fly Apollos 8 and 9, which would respectively conduct the lunar module test flight and the high-orbit mission in late 1968 or early 1969. Since Borman’s crew would be the third flight of the Saturn V, they were known internally as ‘Apollo-Saturn 503’ (AS-503). Not only would it be the first manned launch of the behemoth rocket, but also, wrote Collins, the S-IVB ‘‘would be reignited, just as if it were a lunar mission… However, ours would be shut down early, causing us to stay in Earth orbit’’ with a 6,400 km apogee. ‘‘This little detail created all sorts of planning problems,’’ Collins continued, ‘‘because one could only escape from this lopsided orbit at certain prescribed intervals and if one had troubles and was forced to return to Earth prematurely, it was entirely possible to end up landing in Red China.’’

As 1967 ended with the triumphant first flight of the Saturn V, an increased wave of optimism spread through NASA that the lunar landing could be accomplished, to such an extent that by August of the following year – before Apollo 7 had even flown – some managers were talking of expediting Borman’s mission from high Earth orbit to a lunar distance. An already record-breaking apogee of six and a half thousand kilometres would be multiplied to almost three hundred and seventy thousand. Then, abruptly, in July 1968, Mike Collins was removed from the mission. One day, during a game of handball, he became aware that his legs did not seem to be functioning as they should, a phenomenon which progressively worsened: as he walked down stairs, his knees would buckle and he would feel peculiar tingling and numbness.

Eventually, and with a typical pilot’s reluctance, Collins sought the flight surgeon’s advice and was referred to a Houston neurologist. The diagnosis was that a bony growth between his fifth and sixth cervical vertibrae was pushing against his spinal column and relief of the pressure demanded surgery. A few days later, at the Air Force’s Wilford Hall Hospital in San Antonio, Texas, Collins underwent an ‘anterior cervical fusion’ procedure, whereby the offending spur and some adjoining bone was removed and the two vertibrae fused together with a small dowel of bone from the astronaut’s hip. Several months of convalescence followed, during which time Collins’ backup, Jim Lovell, was assigned to his seat on AS-503 … and something else happened. ‘Apollo 9’ would not be known as Apollo 9 anymore, but as ‘Apollo 8’ and, further, its destination had indeed changed: it would not just fly a basic circumlunar jaunt, but would actually go into orbit around the Moon.

A plan had been under consideration by George Low and Chris Kraft since April 1968 as a means of cutting out one of the seven steps and achieving a landing much sooner. They wanted to change the E mission into something called ‘E-prime’, moving from high Earth orbit to the vicinity of the Moon, but this quickly became untenable when it materialised that the lunar module would not be ready in time.

When it became evident that the first lunar module would not be available until early 1969, George Low came up with a radical idea: in place of the E mission would be a flight known as ‘C-prime’, which aimed to send a command and service module, without the lunar module, around the Moon in December 1968. Low knew from Rocco Petrone, director of launch operations at Cape Kennedy, that the lunar module would not be ready for December, but at a meeting in Bob Gilruth’s office on 9 August it was felt that the navigation and trajectory teams, together with the astronauts and their training staff, could be ready for a Moon shot. The additional risk of actually entering lunar orbit would be beneficial in that it would provide empirical data on orbital mechanics and the formulation of better gravitational models.

Since Jim Webb and George Mueller were at a conference in Vienna at the time, it was left to Deputy Administrator Tom Paine, still sceptical after the Apollo 6 pogo problems and uncertain as to the reliability of the SPS engine, to conditionally approve it. Mueller, with some reluctance, also agreed, but Webb vehemently opposed the idea. He had been particularly lambasted after the Apollo 1 fire and did not want to be hauled over the coals if the Moon shot failed, particularly as the spacecraft had not even been tested with a human crew. On the other hand, of course, he intended to resign from NASA and was finally won over, with reservations, on 16 August. A few weeks later, Webb visited Lyndon Johnson in Washington to announce his resignation. With Webb gone, the prospects for C – prime brightened.

The plan was officially set in motion by NASA on 19 August by Sam Phillips, although some managers remained nervous about making such a bold move before Wally Schirra’s shakedown flight of the command and service module. Officially, until that mission had flown successfully, the ‘new’ Apollo 8 would represent “an expansion of Apollo 7’’, but that ‘‘the exact content… had not been decided’’. The content of the mission may not have been decided, but the crew certainly had been. On 10 August, Deke Slayton told Jim McDivitt that the flight order was being switched: that his D mission with the lunar module would now become Apollo 9, preceded by Borman’s C – prime expedition around the Moon. ‘‘Over the years,’’ McDivitt recounted in Slayton’s autobiography, ‘‘this story has grown to the point where people think I was offered the flight around the Moon, but turned it down. Not quite. I believe that if I’d thrown myself on the floor and begged to fly the C-prime mission, Deke would have let us have it. But it was never really offered.’’ Offered or not, McDivitt acquiesced, he, Scott and Schweickart had been training for so long on the lunar module that they were the best-prepared and wanted to fly its maiden mission.

Privately, Frank Borman was pleased with his lot when he received command of C-prime. McDivitt’s D mission ‘‘was a test-piloting bonanza,’’ wrote Andrew Chaikin, ‘‘and Borman would have gladly traded places.’’ Borman was at North American’s Downey plant, working on tests of Spacecraft 104 – the command module for the E mission – when he was summoned to take a call from Deke Slayton. Shortly afterwards, he was back in Houston, in Slayton’s office, hearing about the C-prime plan, together with disturbing CIA reports that the Soviets might be only weeks away from staging their own manned circumlunar flight. When Slayton asked Borman if he would command Apollo 8 to the Moon, it was essentially a question with only one answer.

Also pleased with the decision was Jim Lovell, Borman’s senior pilot, who had been drafted in only weeks earlier to replace Mike Collins. The pair had, of course, already flown together on Gemini VII and were a good match. Lovell had been planning to take his family – his wife Marilyn and their three children – to Acapulco for Christmas 1968, but was now forced to tell her instead that his yuletide destination had a somewhat different, more exotic and far more extraterrestrial flavour. One evening, flying cross-country with Borman in a T-38 jet, he had sketched a design for Apollo 8’s crew patch onto his kneeboard: a figure-eight emblem, with Earth in one circle and the Moon in the other. With Borman in command, it would be Lovell’s job as senior pilot to oversee Apollo 8’s navigation system, using the command module’s sextant to make star sightings, verify their trajectory and track lunar landmarks. Lovell would be Apollo’s final senior pilot. The next mission, Apollo 9, would feature a lunar module in addition to its command and service modules and the moniker of ‘senior pilot’ would be effectively superseded by that of ‘command module pilot’ (CMP). During subsequent Moon

landing missions, the CMP would fly solo in lunar orbit, requiring them to have previous spaceflight experience. The ‘pilot’ position, in turn, would be replaced by that of ‘lunar module pilot’ (LMP), the man who would accompany the commander down to the Moon’s surface.

One astronaut who was unhappy about the Apollo 9/8 change, though, was Dave Scott. As command module pilot of the D mission, he had nursed Spacecraft 103 — ‘his’ original ship — through testing and preparation at North American and was now being swapped for another vehicle, Spacecraft 104. On the opposite side of the coin, Bill Anders, on Borman’s crew, was also unhappy. Since the beginning of 1968, he had been immersed in lunar module training and would tell Andrew Chaikin years later that he felt he had an 80 per cent chance of a seat on a landing crew. Now, with the change to their flight, the elimination of the E mission and the creation of C – prime, without a lunar module, Anders knew that he had gained the first circumlunar mission, at the expense of probably losing the chance to someday walk on the Moon.

A year before Robert McNamara finally axed the Dyna-Soar, Neil Alden Armstrong’s test-piloting career took a different turn. . . one that would someday guide him to the lunar surface. Armstrong’s life was one of movement. Born in Wapakoneta, Ohio, of Scots-Irish and German descent, on 5 August 1930, his father was a government worker and the family moved around the state for many years: from Warren to Jefferson to Moulton to St Mary’s, finally settling permanently in Wapakoneta in 1944. By this time, Armstrong was an active member of his local Boy Scout group and his mind was filled with dreams of flying. ‘‘I began to focus on aviation probably at age eight or nine,’’ he told NASA’s oral history project in 2001, ‘‘and [was] inspired by what I’d read and seen. My intention was to be an aircraft designer. I later went into piloting because I thought a good designer ought to know the operational aspects of an airplane.’’

When Armstrong enrolled at Purdue University in 1947 to begin an aeronautical engineering degree, he became only the second member of the family to undergo higher study and famously had learned to fly before he could drive. (Years later, he recalled first flying solo aged just 16. Alas, his early logbook entries were lost in a fire at his Houston home in 1964.) Under the provisions of the Holloway Plan, Armstrong committed himself to four years of paid education in return for three years of naval service and a final two years at university. He was summoned to active military duty in January 1949, reporting to Naval Air Station Pensacola in Florida for flight training. Over the next 18 months, Armstrong qualified to land aboard the aircraft carriers Cabot and Wright. A few days after his 20th birthday, he was officially classified as a fully-fledged naval aviator.

His initial assignments were to Naval Air Station San Diego, then to Fighter Squadron 51, during which time he made his first flight in an F-9F Panther – “a very solid airplane” – and later landed his first jet on an aircraft carrier. By late summer in 1951, Armstrong had been detailed to the Korean theatre and would fly 78 missions in total. His first taste of action came only days after arrival, whilst serving as an escort for a photographic reconnaissance aircraft over Songjin. Shortly thereafter, whilst making a low-altitude bombing run, his Panther encountered heavy gunfire and snagged an anti-aircraft cable. “If you’re going fast,” he said later, “a cable will make a very good knife.’’ Armstrong somehow managed to nurse his crippled jet back over friendly territory, but the damage was of such severity (a sheared-off wing and a lost aileron) that he could not make a safe landing and had to eject. Instead of a water rescue, high winds forced his ejection seat over land, close to Pohang Airport, and he was picked up by a jeep driven by an old flight school roommate, Goodell Warren.

By the time Armstrong left naval service in August 1952, he had been awarded the Air Medal, a Gold Star and the Korean Service Medal and Engagement Star. For the next eight years, however, he remained a junior lieutenant in the Naval Reserve. After Korea and his departure from the regular Navy, Armstrong completed his degree at Purdue in 1955, gaining coveted admission to the Phi Delta Theta and Kappa Kappa Psi fraternities and meeting his future wife, home economics student Janet Shearon. They were married in January 1956 and their union would endure for almost four decades, producing three children, one of whom – a daughter, Karen – tragically died in her infancy.

Armstrong’s aviation career, meanwhile, expanded into experimental piloting when he joined NACA, the forerunner of NASA, and was initially based at the Lewis Flight Propulsion Laboratory in Cleveland, Ohio. Whilst there, he participated in the evaluation of new anti-icing aircraft systems and high-Mach – number heat-transfer measurements, before moving to the High Speed Flight Station at Edwards Air Force Base in California to fly chase on drops of experimental aircraft. There, aboard the F-100 Super Sabre, he flew supersonically for the first time. On one occasion, flying with Stan Butchart in a B-29 Stratofortress, Armstrong was directed to airdrop a Douglas-built Skyrocket supersonic research vehicle. Upon reaching altitude, however, one of the B-29’s four engines shut down and its propellor began windmilling in the airstream. Immediately after airdropping the Skyrocket, the propellor disintegrated, its debris effectively disabling two more engines. Butchart and Armstrong were forced to land the behemoth B-29 using the sole remaining engine.

His first flight in a rocket-propelled aircraft came in August 1957 aboard the Bell X-1B, reaching 18.3 km, and three years later he completed the first of seven missions aboard North American’s famous X-15, to the very edge of space. On one of these flights, in April 1962, just a few months before joining NASA’s astronaut corps, he reached an altitude of 63 km. However, during descent, he held up the aircraft’s nose for too long and the X-15 literally ‘bounced’ off the atmosphere and overshot the landing site by some 70 km, but he returned and achieved a safe touchdown. Although he was not one of the handful of X-15 pilots who actually reached space, exceeding 80 km altitude, Armstrong’s abilities in the rocket aircraft have been widely praised. The late NASA research flier Milt Thompson called him ‘‘the most technically capable’’ X-15 pilot.

In November I960, by now flying for NASA as a civilian research pilot, Armstrong was chosen for the Dyna-Soar effort, ultimately leaving the project in the summer of 1962 as the selection process for the second group of astronauts got underway. At around the same time, he last flew the X-15, achieving a peak velocity of Mach 5.74. When his name was announced by NASA in September, he became one of only two civilian astronauts. Although Deke Slayton later wrote that nobody pressured him to hire civilians, fellow selectee Jim Lovell felt that Armstrong’s extensive flying history within NACA and NASA rendered him a likely choice to make the final cut. In fact, Armstrong’s application arrived a week after the 1 June 1962 deadline, but, according to Flight Crew Operations assistant director Dick Day, ‘‘he was so far and away the best qualified… [that] we wanted him in’’.

After admission into the New Nine, Armstrong came to be regarded as by far the quietest and most thoughtful. ‘‘When he said something,’’ recalled Frank Borman, ‘‘it was worth listening to.’’ His Apollo 11 crewmates Mike Collins and Buzz Aldrin would both characterise his nature as ‘‘reserved’’ and Dave Scott, the man who would fly with him aboard Gemini VIII, described him as ‘‘cool, calm and energised’’, who never operated in a frantic manner, but who could identify and resolve problems quickly, efficiently and smartly. All of these qualities would prove vital on his first spaceflight, when he would come close to losing his life.

Bob Crippen, Dick Truly, Gordo Fullerton, Hank Hartsfield, Bob Overmyer, Karol ‘Bo’ Bobko and Don Peterson: to most space aficionados, their names will forever be connected to the early test flights of the Shuttle. However, prior to their NASA days – and more than a decade before each would make an orbital voyage – all seven almost found fame as the first men to inhabit a long-term space station. Yet they were not, insisted their sponsor, the Air Force, ‘astronauts’, but rather ‘aerospace research pilots’, with an agenda that remains largely classified to this day. ‘‘When the manned space programme started,’’ remembered Peterson in a 2002 oral history for NASA, ‘‘the Cold War was in full swing. We were scared to death and there was this feeling that space was the high ground; that is, if you conquered space, you had command of Earth. The idea that the Russians might be ahead of us was pretty frightening, so there was strong public and government support for the manned space programme and an unlimited budget.’’

The most visible example of the seemingly bottomless moneypit available for space exploration during this period was, of course, Project Apollo, but in May 1966, more than $1.5 billion was pledged by President Lyndon Johnson for a space-based outpost known as the Manned Orbiting Laboratory (MOL). Had this actually reached fruition, it would have provided Peterson, his six colleagues and a handful of others with their first space missions and made them the first men ever to launch into the heavens from the United States’ west coast.

Ideas for a military space station can be traced back to June 1959, when preliminary plans were laid for a two-man laboratory to support a range of biomedical, scientific and engineering tasks in the microgravity environment of low – Earth orbit. Within three years, these sketches had crystallised into a formal proposal for three separate cylindrical modules, launched separately atop Titan II boosters and joined together in space to form a triangular structure. Crews would then be ferried to and from MOL using an Air Force variant of NASA’s Gemini spacecraft, launched from Vandenberg Air Force Base in California.

At one stage, it was envisaged that the laboratory may operate in tandem with Dyna-Soar – the reusable winged craft which, in a different life, Neil Armstrong might have flown – but by December 1963 it seemed inevitable that the latter would be cancelled in favour of MOL. Eitherway, the perceived ‘militarisation’ of space caused concern for many observers, including James Haggerty of the Army-Navy – Air Force Journal and Register, who described MOL as ‘‘an ominous harbinger of a reversal in trend, an indication that the services may play a more prominent role in future space exploration at NASA’s expense. ‘‘Whether you label it a development platform, satellite or laboratory, it is clearly intended as a beginning for space station technology,’’ continued Haggerty. ‘‘It is also clearly the intent of this [Johnson] administration that, at least in the initial stages, space station development shall be under military rather than civil cognisance.’’

Moreover, despite its official emphasis on biomedical research and evaluating humanity’s effectiveness in space, President Johnson rather tellingly announced in August 1965 that the ultimate aim of MOL was to ‘‘relate that ability to the defence of America”. The dedication of the outpost to exclusively military activities was further underlined by the head of the Air Force’s aerospace medicine group, Stan White, at a meeting with NASA representatives in May 1966, when he called for greater exploitation by the military of the agency’s biomedical data. This, White argued, would relieve MOL’s pilots of having to conduct such experiments, which the Air Force regarded as a burden to their own research. One of the most important military investigations was reconnaissance and surveillance, employing large optics, powerful cameras and side-looking radar.

It had already been realised from early spy satellites that having trained military observers available in orbit with specialised equipment would permit the real-time selection of ground-based targets and the acquisition of images through gaps in cloud cover. Furthermore, the return and interpretation of Corona reconnaissance satellite images typically took weeks or months, a lapse that the Air Force could not afford. With this in mind, the central element of MOL’s surveillance payload was a telescope dubbed ‘Dorian’, fitted with a 1.8 m-wide mirror and supposedly capable of resolving ground-based objects the size of a softball.

Other surveillance instruments included high-resolution optical and infrared cameras, the side-looking synthetic-aperture radar, built by the Navy, with a resolution of 7.5 m – later cancelled because it was too large and heavy to be easily placed into orbit – and an electronic intelligence antenna. Much of the Dorian hardware, analysts have speculated, was probably later employed on KH-9 Big Bird and KH-11 Kennan reconnaissance satellites and may offer hints that both the CIA and Air Force doubted that MOL would ever fly.

For the ‘aerospace research pilots’ selected to travel to the outpost, there were also doubts, but in Hank Hartsfield’s mind they centred on budgetary matters, as more money was siphoned away from MOL to finance the escalating conflict in Vietnam. Every year, with depressing predictability, Hartsfield recalled, the project would have its funding cut and be forced to lay off contractors, placing MOL further and further behind schedule. . . and doubling its cost. In fact, by the time Stanley White’s team met with NASA at Brooks Air Force Base in Texas to discuss the sharing of biomedical data, MOL had already guzzled $2.2 billion of taxpayers’ money. The station, in its final configuration, was quite different from the three – module triangular structure planned in 1962: it took the form of a 12 m-long cylinder, powered by solar arrays or fuel cells, and comprised a transfer tunnel from the Gemini spacecraft, a laboratory divided into ‘working’ and ‘living’ quarters and an equipment section filled with oxygen and other tanks. One early plan actually called for a tunnel in the base of the laboratory, extending to an aft docking collar, which would enable two MOLs to be linked together in orbit. Such plans were never realised and had vanished from the Air Force’s radar long before the project was cancelled in June 1969.

An interesting aspect of MOL was that the Gemini would have been attached ‘backwards’ to the outpost: rather than docking ‘nose-first’, as Apollo did with Skylab, it was through a hatch in the base that crews would have passed to reach their 30-day home in orbit. Gemini was very cramped and enabling pilots to unstrap, turn around and get through a 60 cm-wide hatch behind them would have been tricky. As a result, the Air Force tilted the seats slightly apart, as well as completely redesigning the spacecraft’s instrument displays. However, it was not the size of the Gemini that caused concern; rather, it was the hatch in its heat shield – the very component upon which the crew’s lives would depend during their fiery re-entry through the atmosphere.

The spacecraft and its pilots would have ridden into orbit already attached to MOL, neatly sidestepping the complications of rendezvous or docking, but at the end of their two-to-four-week mission, after closing the hatch, they would have had to hope that the tiniest – yet potentially deadliest – gap around the edge of the heat shield would not admit hot gases and tear the Gemini apart. As a result, it was decided to attach a MOL mockup, built from the propellant tank of a Titan II rocket, to NASA’s Gemini 2 spacecraft and launch them on an unmanned test of the new hatch. On 3 November 1966, the unusual combo lifted-off from Pad 40 at Cape Canaveral and instantly made history as Gemini 2 became the first ‘used’ spacecraft to be refurbished and reflown. Originally launched in January 1965, it had been modified by the Air Force with a MOL-specification hatch in its base. Following a 33-minute suborbital flight, it separated from the MOL mockup and began its fiery plunge to Earth. ‘‘It came through with flying colours,’’ exulted Hartsfield. ‘‘There was no heating problem or any burn-through. It proved the concept.’’

However, one of the key objectives of MOL was that it would operate in polar orbit, which would have resulted in higher-energy re-entries; consequently, the heat shield’s diameter was increased to stick out from the base of the Gemini. Other changes from the standard NASA version of the spacecraft were that its OAMS thrusters were removed and its orientation managed instead by several forward – mounted reaction-control thrusters. Unlike the ‘civilian’ Gemini, designed to operate for periods of up to a fortnight with two men aboard, the systems of the Air Force variant were intended for longer-term, untended ‘storage’.

After reaching orbit, the men’s first task would be to shutdown the spacecraft and begin their long mission aboard MOL. They would reawaken the slumbering Gemini’s systems just before re-entry, undock from the outpost and commence their descent. To this end, the spacecraft had only a 14-hour ‘loiter’ capability in its thrusters and life-support systems after separating from MOL. Naturally, the two groups of astronauts – NASA and Air Force – prepared in similar ways to fly different versions of the same machine and Hartsfield later provided some insight into his first experience as a trainee spacefarer. ‘‘We got some of the routine survival training,’’ he said. ‘‘We’d had water survival [and] we’d gone down to Panama for jungle survival. We were getting that kind of training to get ready to go, because we were going to fly out of Vandenberg into a high-inclination orbit, which meant you covered a pretty good piece of the world. If you had to abort, you could almost go anywhere – jungle or polar regions.’’

Even three decades later, both he and Don Peterson were reluctant to talk much about their specific tasks and restricted their descriptions to ‘generic’ issues. ‘‘Of course,’’ recalled Peterson, ‘‘we were flying a capsule in those days, so we were going to land in the water. The Earth is two-thirds water and you might come down someplace that you hadn’t planned, [so] you had to be able to stay afloat and alive maybe for several days until [the Air Force] could get to you. Finding people in those days wasn’t nearly as good as it is now.’’

To this day, it is unclear which MOL missions Hartsfield or Peterson would have flown, although the first – targeted for February 1972 at the time of the project’s cancellation – would have been conducted, appropriately, by two Air Force pilots: Jim Taylor and Al Crews. Further two-man teams would then have been despatched at nine-month intervals for roughly 30-day orbital stays until the fifth and final manned mission in February 1975. At least one MOL flight, it was expected, would carry two naval officers, probably Bob Crippen and Dick Truly. The pilots, like the project itself, were supposed to be highly classified. However, there was a problem. One of them, Bob Lawrence, would have become the first African-American spacefarer when MOL finally flew and, naturally, the media grew to recognise him. “The rest of us were unknowns,’’ said Don Peterson, “and f could travel on false IDs and nobody had any idea who f was. But [the Air Force] worried because [the press] knew him on sight and it becomes much harder to run a secret programme when one of your guys is a high interest to the media.’’

Tragically, Lawrence died in an aircraft crash in 1967, two years before MOL was cancelled. Both Peterson and Hartsfield are convinced that, had he lived, he would have gone on to join NASA and probably would have flown the Shuttle…

After unstrapping and curling and twisting themselves around and through the hatch in the base of their Gemini, the MOL crews would first have drifted along a tunnel surrounded by cryogenic storage tanks for helium, hydrogen and oxygen to supply the station’s atmosphere and fuel cells. fndeed, following the Apollo 1 disaster in January 1967, it was intended that MOL would have an atmosphere of 31 per cent helium and 69 per cent oxygen, pressurised at 0.34 bars, to reduce the risk of fire or detrimental medical effects on the pilots. The only adverse effect, it seemed, would have been some unusual chatter from the crew as they climbed to orbit: after breathing pure oxygen into their space suits, helium would also have been steadily pumped into the Gemini to better acclimatise them to the MOL environment. One can imagine that there would have been a few light-hearted smirks and chuckles among flight controllers as they listened in to the squeaky voices of two high-on – helium space explorers. . .

After entering the outpost, and floating between the cryogenic storage tanks, the crew would have found themselves in its pressurised section. This was organised into two ‘stories’, each furnished with eight bays nicknamed ‘the birdcage’. Providing further hints as to the kind of work the men would have done, these bays would have contained biochemical test consoles, an experiment airlock, a glovebox for liquids handling, a motion chair on rails, a physiology console to monitor their health and an Earth-facing viewport.

By the end of the Sixties, however, with a launch seemingly getting closer, the reality was that MOL was drifting further into oblivion. Members of the workforce complained that, no matter how hard they worked, the project always appeared to be at least a year away from launch. ‘‘General Bleymaier was the commander,’’ recalled Don Peterson, ‘‘and he finally went to [President Richard] Nixon and said ‘Either fund this programme or kill it, because we’re burning time and money and we’re not making progress because we don’t have enough funds’.’’ After cuts to the number of technical personnel, followed by woefully inadequate budgetary allocations, Nixon finally cancelled MOL on 10 June 1969 to save an unspent $1.5 billion of its estimated total price tag. The Outer Space Treaty, signed two years earlier, had already imposed enough restrictions on the Air Force to effectively demilitarise many of their proposed activities in Earth orbit and the Vietnam conflict continued to soak up more funds.

By now, MOL had swallowed close to three billion dollars, without even a single, full-scale unmanned flight. For the pilots, its cancellation was devastating. ‘‘We all thought it was going to come to fruition,’’ said Bo Bobko in a 2002 oral history. ‘‘It was a surprise that it was just cancelled one day. I can remember I had a classmate from the Air Force Academy [who] had come to the MOL programme and it was his first day and they called everybody down to the auditorium and [told us that it had] been cancelled.’’

Hank Hartsfield, who was travelling to Huntington Beach in California, was also astonished, particularly in light of the work accomplished thus far. ‘‘The crew quarters were built, the training building was built, the pad was 90 per cent complete,’’ he remembered. ‘‘It broke our hearts when it got cancelled. I won’t forget the day. I was on my way to a meeting, listening to the news and they announced the cancellation. When I got to [prime contractor] Douglas and walked in, it was like walking into a morgue. It caught them completely by surprise. They heard it on the radio, like I did, or they came to work and found they didn’t have a job. It was massive layoffs. People were getting pink slips almost immediately on the contractor force. . . a very unhappy day.’’

For the Air Force pilots, the next step seemed to be to volunteer for Vietnam, although they were excluded from flying in combat. ‘‘We had a two-year duty and travel restriction,’’ said Hartsfield, ‘‘because of the classified things we’d been exposed to. We couldn’t be put in an environment where we could get captured.’’ Several of the MOL pilots did return to active duty, but seven – Hartsfield, Peterson, Bobko, Crippen, Truly, Overmyer and Fullerton – were hired in September 1969 as NASA’s seventh group of astronauts. After a wait of more than a decade, each flew at least one Shuttle mission and, in Crippen’s case, as many as four. In fact, the final irony of MOL seems to be that, had Challenger not exploded in January 1986, Crippen would have commanded Shuttle mission STS-62A – the first-ever manned space launch from the United States’ west coast, just as he had been trained to do almost two decades earlier. . .

When Bill Anders joined NASA in October 1963, he stood out: among the Fourteen, six astronaut candidates lacked test-piloting credentials, and he was one of these apparent ‘outsiders’. As a child, he had never had aspirations of becoming a test pilot, but rather wanted to follow in the footsteps of his father, Arthur Anders, and become a career naval officer. William Alison Anders was born in Hong Kong on 17 October 1933 and, in his youth, was an active Boy Scout, receiving its second-highest rank. He earned a bachelor’s degree from the Naval Academy in 1955, but opted for a commission in the Air Force, serving as a fighter pilot in an all-weather interceptor squadron in Iceland.

Anders’ decision to move away from naval service was made in part by the extraordinary number of fatal accidents he saw as a midshipman: one aircraft, for example, landed on the carrier, missed the arresting net, hit a line of parked jets, careered off the deck and plunged into the sea. Anders accepted the risks of his new­found love of aviation, but preferred to face such risks in air-to-air combat, rather than whilst attempting to land. After Iceland, Anders’ next step, with 1,500 hours in his flight logbook, was to apply for test pilot school. He was rejected, on the basis that the school was ‘‘pushing academics’’ and desired him to earn an advanced degree.

With test pilot school still at the back of his mind, Anders enrolled in the Air Force Institute of Technology at Wright-Patterson Air Force Base in Dayton, Ohio, graduating with a master’s degree in nuclear engineering in 1962. He had wanted to study astronautical engineering, but places were full, although Anders simulta­neously took night school classes in aeronautics at Ohio State University. Upon receipt of his master’s qualification, Anders again tried for test pilot school, only to learn that it was not recruiting students, and he moved instead to become a T-33 instructor pilot at Kirtland Air Force Base in Albuquerque, New Mexico.

The following year, 1963, proved life-changing for Anders. He again applied for test pilot school, only to learn that now, under the new commandant, Chuck Yeager, it was looking for candidates with more flying experience. Unperturbed, he submitted his application and in June, whilst waiting to hear of the outcome, he learned that NASA were recruiting for its new class of astronauts. Test piloting qualifications, it turned out, were no longer mandatory and Anders had everything that the space agency needed: he was younger than 35, had an advanced degree and his logbook had now expanded to more than the 2,000 required hours.

When he was called to interview, Anders stressed his nuclear engineering work, aware that flights to the Moon would surely require an understanding of radiation hazards in cislunar space. That October, he was picked as one of the Fourteen… and, ironically, received a letter rejecting him from test pilot school! In his early years as an astronaut, Anders supervised Apollo’s environmental controls and his performance as the capcom during the Gemini VIII emergency in March 1966 quite possibly contributed to his assignment as Neil Armstrong’s pilot on the Gemini XI backup crew. By the end of that year, Anders had drawn his first actual flight assignment: to Frank Borman’s E mission, during which he hoped to get the opportunity to test-fly the lunar module in high Earth orbit. All that changed in August 1968 when Anders became a part of history: one of the first human explorers to visit the Moon.

In a strange kind of way, Neil Armstrong’s work during his first couple of years as an astronaut had helped pave the way for the selection of Dave Scott, his 33-year-old colleague aboard Gemini VIII. Deke Slayton had given Armstrong responsibility for mission operations and training and entrusted him to devise a system which would identify how many astronauts would be needed at any given time. It was this schematic, wrote James Hansen in his biography of Armstrong, that ‘‘allowed Slayton to determine when additional astronauts needed to be brought in. . . culminating in Houston’s announcement in June 1963 that NASA was looking for a new class of astronauts’’.

Slayton’s decision, he recounted, ‘‘was based on planning documents that were starting to arrive from [NASA] Headquarters’’. The 1962 astronaut intake, together with the remaining members of the Mercury Seven who were still on flight status, barely provided enough seats for Project Gemini. Early predictions for Apollo envisaged at least 12 missions in Earth and lunar orbit before a landing on the Moon could be attempted. That required Slayton to accept ‘‘a minimum of ten new astronauts in 1963 and… as many as twenty”. Fourteen newbies duly arrived in Houston in October of that year.

Although the selection criteria changed slightly – a more rigid upper age limit of 34 and the elimination of the need for the new astronauts to be test pilots being the main differences – David Randolph Scott still fitted perfectly into the classic mould of a spacefarer. Tall, athletic and with a middle name honouring the Air Force base on which he was born, it has often been said that it was no accident that Scott was the first of the 1963 group of astronauts to fly into space… and eventually would become the first of his class to command a mission. “In some circles,” noted Andy Chaikin in his book about Project Apollo, “there was a joke that if NASA ever came out with an astronaut recruiting poster, Dave Scott should be on it.” Further, Chaikin added, even astronauts who did not get on with Scott placed him at the top.

Despite the near-disaster which befell it, Gemini VIII marked the only mission in which the entire crew would one day set foot on the Moon; Armstrong as the first man to tread its dusty surface at the Sea of Tranquility and Scott in command of Apollo 15 in July 1971.

Scott was born on Randolph Air Force Base in San Antonio, Texas, on 6 June 1932, the son of an Air Force officer and progeny of a strict, frugal military family who instilled in him the virtues of personal discipline and devotion to setting and achieving ambitious life goals. In his autobiography, jointly co-authored with cosmonaut Alexei Leonov, Scott recalled watching Jenny biplanes soaring over Randolph as a three-year-old boy and was fascinated that aboard one of them was his father, Army Air Corps flier Tom Scott. From that tender age, the young Scott set his sights on someday becoming a pilot.

With a military father, the family moved many times during his childhood, from Texas to Indiana, abroad to the Philippines and, in 1939, back to the United States. Scott’s father was posted overseas after Pearl Harbour to support the war effort and the young boy developed an interest in model aircraft. Then, when his father returned at the end of the conflict, Scott received his first flying lesson.

Despite a desire to study at West Point, Scott won a swimming scholarship to read mechanical engineering at the University of Michigan in 1949. After a year in Michigan, he was summoned for a physical at West Point, passed and headed to upstate New York to begin preparations for a military career. In his autobiography, Scott would credit his four years at West Point – plus his own upbringing – as “the most valuable and formative… of my life’’.

Ultimately, in 1954, he graduated fifth in his class and opted to join the Air Force, receiving initial flight training at Marana Air Force Base in Tucson, Arizona. He subsequently moved to Texas to begin working on high-performance jets, followed by gunnery preparation and assignment to a fighter squadron in Utrecht, Holland. Whilst in Europe, Scott flew F-86 Sabre and F-100 Super Sabre jets under a variety of weather conditions and, in October 1956, when Soviet tanks rolled into Budapest, his squadron was placed on high alert for the first time.

Three years later, as the Mercury Seven were introduced to the world’s media, Scott watched from afar with scepticism; why, he wondered, were they abandoning

such promising military careers? His own focus was upon gaining an advanced degree in aeronautics from Massachusetts Institute of Technology (MIT) and achieving admission to test pilot school. His work at MIT, he later wrote, “was like trying to drink water from a high-pressure fire hydrant… Compared to the hard grind of MIT, the five or six years I had spent flying fighter jets felt like playing.” He and his wife, Lurton, also had a newborn daughter, Tracy.

As part of his master’s degree, Scott was introduced to the new field of ‘astronautics’ – “my first exposure to space’’ – and his dissertation focused upon the mathematical application of guidance techniques and celestial navigation. This undoubtedly proved of benefit during Projects Gemini and Apollo, both of which depended heavily upon rendezvous and docking. Scott passed his final exams shortly after John Glenn’s Friendship 7 mission, hoping for reassignment to test pilot school… only to be detailed instead as a professor of aeronautics and astronautics at the Air Force Academy. Fortunately, a conversation with a sympathetic superior officer led to a change of orders and Scott reported to the Experimental Test Pilot School at Edwards Air Force Base in California.

Graduation was followed, in mid-1963, by the lengthy application process to join NASA’s astronaut corps. In his autobiography, Scott recalled undergoing cardiograms, running on treadmills and enduring hypoxia evaluations, in which he was starved of oxygen to assess his physical response. The psychologists were especially difficult to please. When asked about his MIT days and how he had liked Boston, Scott replied that he found New Englanders cold, aloof and ‘‘a little hard to get to know’’ … only to discover that the stone-faced psychologist was a born-and – raised Bostoner!

It obviously had little adverse impact on his application, however, and in October 1963 Scott and 13 other candidates – Edwin ‘Buzz’ Aldrin, Bill Anders, Charlie Bassett, Al Bean, Gene Cernan, Roger Chaffee, Mike Collins, Walt Cunningham, Donn Eisele, Ted Freeman, Dick Gordon, Rusty Schweickart and Clifton ‘C. C.’ Williams – were notified of their assignment to NASA. Of these, eight were test pilots, whom Slayton intended to use ‘‘for the more immediately difficult work’’ as solo command module pilots for the Apollo missions, while the others represented a mixture of operational military fliers, engineers or researchers. The latter, added Slayton, ‘‘would get their chance, too, but on the development end of things’’. The excitement of the accelerating lunar effort, Scott wrote, was palpable, even in the wake of President John Kennedy’s assassination a few weeks later.

The new astronauts worked together surprisingly well, with the Air Force pilots kidding their Navy counterparts that they couldn’t bring their jets down without a thump. In return, the naval aviators retorted that the Air Force fliers needed far too much runway on which to land. Despite the steadily burgeoning number of astronauts, they were still offered deals on cars, small Life magazine contracts and ‘‘the banks all wanted to have our accounts’’. Unlike the Mercury Seven, however, their privacy was better respected and their wives and children were pestered less by journalists from other publications.

After initial training, Scott was assigned guidance and navigation as his area of responsibility and in June 1965 served as one of the backup capcoms for Gemini IV and America’s first spacewalk. Less than three months later, at the end of August, Deke Slayton caught up with him for “a word’’. Now that Gemini V was over, Slayton said, Neil Armstrong was free from his backup duties and would be teamed with Scott for Gemini VIII, scheduled for March 1966. The mission, Slayton added, would involve a lengthy, two-hour EVA for Scott. The boy from Randolph Air Force Base could not have been more delighted.

Not long after his return from Gemini IX-A, astronaut Gene Cernan was summoned to Deke Slayton’s office and posed an unusual question.

‘‘Geno, how soon can you be ready to fly again?’’

‘‘Just say the word, Deke. When?’’

“Right now. Would you be willing to jump from backup to prime? Fly [Gemini] XII with Lovell?”

The year 1966 had certainly been a dramatic one for Cernan. When it began, he and Tom Stafford confidently looked forward to flying Gemini XII – the last manned mission in the series – themselves. Then, with awful suddenness, the deaths of Elliot See and Charlie Bassett in February pushed them from backup to prime crew on Gemini IX. Following his return from his first spaceflight, Cernan had been given a ‘dead-end’ slot, with Gordo Cooper, to back up Jim Lovell and Buzz Aldrin on Gemini XII. Now, with barely two-thirds of the year gone, Slayton was offering to break his own crew-rotation system, bumping Aldrin from the mission. Cernan’s first question to Slayton was a simple one. Why?

The reason was the Astronaut Manoeuvring Unit (AMU) – the Air Force-built rocket armchair which Cernan was originally detailed to test in June 1966 – whose military sponsors were pushing strongly to fly again on Gemini’s last mission. Without giving much away, Slayton told Cernan simply that he was the best man to fly the AMU, which was probably true, but a number of contributory factors centred on Buzz Aldrin himself: a man of mathematical and engineering genius, the first astronaut to possess a doctorate, an unquestioned expert in the field of space rendezvous. . . and a constant worry to Slayton. Aldrin had already raised eyebrows during Gemini IX-A, specifically those of Bob Gilruth and Chris Kraft, when he advocated having Cernan cut the lanyards of The Blob. Although not an outrageous suggestion, Slayton acquiesced, Aldrin’s advice was a little too adventurous in light of NASA’s limited EVA expertise.

Gilruth, Kraft and Slayton were not the only ones with worries about Aldrin. In his autobiography, Cernan hinted strongly that Aldrin’s intelligence was tempered by a seeming inability to stick to one topic: he had a tendency to fly off at tangents and drastically re-engineer everything, at a time when NASA had little time to do so. Astronauts and their wives would roll their eyes when Aldrin collared them, even over coffee, and engaged them in hours-long discussions of the intricacies of celestial navigation and mechanics. Coupled with reports of his performance in the Gemini simulators, it was Slayton’s judgement that the AMU test flight should be entrusted to Cernan, rather than Aldrin.

In his own defence, Aldrin would blame the decision on problems experienced by both Cernan and Dick Gordon on their EVAs: exhaustion, fogged-up visors and a difficulty in performing even simple tasks. ‘‘An urgent meeting of senior officials concerned with the Gemini XII EVA,’’ Aldrin wrote, ‘‘was held at the end of September and… they decided arbitrarily that I stood a poor chance of putting the innovative AMU backpack to good use. They felt the risks outweighed the benefits.’’

Despite the risks to his colleague’s career, Cernan accepted Slayton’s invitation on the spot – ‘‘when Deke asked if you would take a mission, there was only one answer’’ – and would have flown Gemini XII had not the decision been made that an AMU test was too risky. Gemini XII’s EVAs would focus instead on less dramatic evaluations of a spacewalker’s performance outside the pressurised confines of his spacecraft. Edwin Eugene Aldrin Jr, nicknamed ‘Dr Rendezvous’ behind his back, retained his place on the mission. Born in Glen Ridge, New Jersey on 20 January 1930, the son of an Army Air Corps pilot and a mother whose maiden name, propitiously, happened to be ‘Moon’, Aldrin’s development, even into adulthood, was very much guided by his father.

Naturally, in light of his father’s career, the man who would someday fly Gemini XII and become the second person to walk on the Moon was brought up with aviation in his blood. He first flew aboard an aircraft with his father in 1932, when he was barely two years old. (As a child, he earned the nickname ‘Buzz’ from his young sister, who, unable to pronounce ‘brother’, called him her ‘buzzer’.) Graduation was followed by enrolment in a military ‘poop school’ – aimed at preparing him for the Naval Academy at Annapolis – although Aldrin sought the Military Academy at West Point. Despite his father’s outspoken preference for the Navy, which he considered ‘‘took care of its people better’’, his son persisted and eventually won his reluctant approval.

When Aldrin graduated third in his class from West Point in 1951, his father’s immediate reaction was a question: who had finished first and second? He was not accepted for a coveted Rhodes postgraduate scholarship and instead entered the Air Force, earning his pilot’s wings later that same year after initial training in Bryan, Texas. During the conflict in Korea, Aldrin was attached to the 51st Fighter Wing, flying F-86 Sabres, and by the time hostilities ended in the summer of 1953 he had no fewer than 66 combat missions in his military logbook. Just a month before the end of the war, one of Aldrin’s gun-camera photographs – a Russian pilot ejecting from his stricken MiG – ended up in Life magazine.

In total, Aldrin returned from Korea having shot down three MiGs. Back in the United States, he became a gunnery instructor at Nellis Air Force Base in Nevada and in 1955 was accepted into Squadron Officer School in Montgomery, Alabama. At around the same time, he met and married Joan Archer and shortly thereafter became the father of a son, James. Professionally, his military career prospered: he was assigned as an aide to General Don Zimmerman, the dean of the new Air Force Academy, then moved to Germany in 1956, flying the F-100 Super Sabre as part of the 36th Fighter-Day Wing, stationed in Bitburg. During this time, he became a father twice more: to Janice and Andrew.

Before pursuing his next ambition of test pilot school, Aldrin, like his Bitburg flying comrade Ed White, sought to gain further education and was accepted into the Massachusetts Institute of Technology on military detachment for a doctorate of science degree in astronautics. His 259-page ScD thesis, completed in 1963, just months before his selection as an astronaut, was entitled ‘Line of Sight Guidance Techniques for Manned Orbital Rendezvous’. He chose the topic, he later wrote, because he felt it would have practical applications for the Air Force and aeronautics, although it also drew the attention of NASA, which was by now looking at lunar-orbital rendezvous for its Apollo effort.

Aldrin dedicated his thesis to future efforts in human exploration, wistfully remarking ‘‘if only I could join them in their exciting endeavours’’. By this time, of course, his application for the 1963 astronaut class was already being processed; he had tried to gain admission the previous year, seeking a waiver for his lack of test – piloting experience, but this time achieved success. A concern about his liver function, thanks to a bout of infectious hepatitis, did not prevent Aldrin from becoming one of the 14 astronauts named to the world that October.

Assigned to work on mission planning, his early days saw him focusing his attention on rendezvous and re-entry techniques… and, gradually, as each Gemini crew was named, he became increasingly frustrated that he was receiving no flight assignment. At one stage, he even approached Deke Slayton to stress his confidence in his own abilities – that his qualifications and understanding of orbital rendezvous far exceeded those of anyone else in the office – and was politely told that his comments would be noted.

Shortly thereafter, in early 1966, Aldrin and Jim Lovell were assigned as the backup team for Gemini X. His heart sank. Taking into account Slayton’s three – flight rotation system for backup-to-prime crews, there would be no Gemini XIII to which Aldrin and Lovell could aspire. It was, in effect, a ‘dead-end’ assignment. “Apparently, petitioning Deke – an arrogant gesture by ‘Dr Rendezvous’ – had not been well-received by the stick-and-rudder guys in the Astronaut Office,’’ Aldrin wrote. ‘‘By being direct and honest rather than political, I’d shafted myself.’’ All that changed on the last day of February, when See and Bassett were killed and their Gemini IX backups were pushed into prime position. In mid-March, Lovell and Aldrin were named as the new Gemini IX backups, with a formally-unannounced (but anticipated) future assignment as the prime Gemini XII crew.

For Aldrin, whose Nassau Bay backyard bordered that of the Bassetts, it was a devastating way to receive his long-desired flight assignment. Three weeks after the accident, he and Joan visited Jeannie Bassett to tell her the news. ‘‘I felt terrible,’’ he wrote, ‘‘as if I had somehow robbed Charlie Bassett of an honour he deserved.’’ Jeannie responded with quiet dignity and characteristic grace: her husband, she explained, felt that Aldrin ‘‘should have been on that flight all along. . . I know he’d be pleased’’.