Category Escaping the Bonds of Earth

Preparations for the MA-7 mission had begun long before Deke Slayton’s grounding. In mid-November 1961, Spacecraft No. 18 arrived in Hangar S at Cape Canaveral, followed, shortly after the Friendship 7 flight, by its Atlas. Checkout problems with capsule and rocket delayed an original mid-April launch to mid-May. The landing bag switches which had caused problems for John Glenn were rewired so that both had to be closed in order to activate a ‘deployed’ signal. Engineers also determined that the cause of the flight control system glitches lay in the fuel line filters, which were replaced with platinum screens and new, stainless steel fuel lines. Finally, on 28 April 1962, Aurora 7 was attached to its rocket at Pad 14. A simulated flight proved satisfactory, although decisions were made to install an extra barostat in the capsule’s parachute circuitry, fit temperature survey instrumentation and replace flight-control canisters in the launch vehicle. Additional delays were caused by Atlantic Fleet tactical exercises which required participation by the recovery ships and aircraft for several weeks. Other concerns arose following the failure of an Atlas – F missile a few weeks earlier. However, the different engine start-up sequences of the Atlas-F and Carpenter’s own Atlas-D eliminated any doubts over its reliability.

The installation of the extra barostat postponed the mid-May launch attempt and, on the 19th, an effort to get Aurora 7 into space proved fruitless when irregularities were detected in a temperature control device on the Atlas’ flight control system heater. Five days later, however, Carpenter was awakened at 1:15 am and proceeded through the usual pre-flight breakfast ritual, was examined by Bill Douglas, suited – up by Joe Schmitt’s team and departed for Pad 14. He was aboard the capsule by 5:00 am, to enjoy one of the smoothest countdowns in Project Mercury, with only persistent ground fog and cloud and camera-coverage issues complicating matters. During a 45-minute delay past the original 7:00 am launch time, Carpenter sipped cold tea from his squeeze bottle and chatted to his family over the radio. His wife Rene and their four children represented the first astronaut family to journey to the Cape and watch the launch. To avoid media attention, a neighbour provided a private flight to Florida and a car, which Rene drove to the astronauts’ hideaway – nicknamed the Life House – near Pad 14, wearing huge sunglasses, a kerchief over her conspicuous blonde coif and her two daughters hidden under a blanket. The media, anticipating the arrival of a blonde mother of four, instead saw only a well – disguised mother of two. . .

Sixteen seconds after 7:45 am, the Atlas’ engines ignited, prompting all four Carpenter children to abandon the television set and rush onto the beach to watch their father hurtle spaceward. Elsewhere, at the Cape and across the nation, an estimated 40 million viewers watched as America launched its second man into orbit. Carpenter himself would later describe ‘‘surprisingly little vibration, although the engines made a big racket’’ and the swaying of the rocket during the early stages of ascent was definitely noticeable. In his autobiography, he would express surprise, after so many years of flying aircraft and ‘levelling-out’ after an initial climb, to see the capsule’s altimeter climbing continuously as the Atlas shot straight up.

Already, however, the first glitches of what would become a troubled mission

were rearing their heads. Aurora 7’s pitch horizon scanner, responsible for monitoring the horizon to maintain the pitch attitude of the spacecraft, immediately began feeding incorrect data into the automatic control system. When this ‘wrong’ information was analysed by the autopilot, it responded, as designed, by firing the pitch thruster to correct the perceived error – in effect, wasting precious fuel. Forty seconds after the separation of the LES tower, the scanner was 18 degrees in error, indicating a plus-17-degree nose-up attitude, whilst the Atlas’ gyros recorded an actual pitch of minus 0.5 degrees. It had reached 20 degrees in error by the time Carpenter achieved orbit. As the flight wore on, the error persisted and, wrote Carpenter and Stoever, produced ‘‘near-calamitous effects’’ as Aurora 7 neared re­entry.

Sustainer engine cutoff came as a gentle drop in acceleration, with a pair of bangs providing cues that explosive bolts had fired and posigrade rockets had pushed Aurora 7 away from the spent Atlas. The astronaut reported, with clear elation in his voice, ‘‘I am weightless! Starting the fly-by-wire turnaround.” Deciding not to rely on the automatic controls, his use of fly-by-wire smartly turned the capsule around at a fuel expense of just 725 g, as compared to 2.3 kg on Friendship 7. Carpenter would later describe that he felt no angular motion during the turnaround and, in fact, his instruments provided the only evidence that a manoeuvre was being executed. No sensation of speed was apparent, although he was travelling at 28,240 km/h and was soon presented with his first ‘‘arresting’’ view of Earth. Carpenter watched the Atlas’ sustainer tumble into the distance, trailing a stream of ice crystals two or three times longer than the rocket stage itself. As he flew high above the Canaries, he could still see its silvery bulk, tagging along with Aurora 7.

Five and a half minutes into the mission, Capcom Gus Grissom radioed the good news: Carpenter’s orbit was good enough for seven circuits of the globe. The astronaut got to work. ‘‘With the completion of the turnaround manoeuvre,’’ he wrote, ‘‘I pitched the capsule nose down, 34 degrees, to retro attitude, and reported what to me was an astounding sight. From Earth orbit altitude, I had the Moon in the centre of my window, a spent booster tumbling slowly away and looming beneath me the African continent.’’ He pulled his flight plan index cards from beneath Aurora 7’s instrument panel and Velcroed them into place; these would provide him with timing cues for communications with ground stations, when and for how long to use control systems, when to begin and end manoeuvres, what observations to make and when to perform experiments. Minute-by-minute, they mapped out his entire flight. First, he took out the camera, adapted with strips of Velcro – ‘‘the great zero-gravity tamer’’ – to begin photographing Sun-glint on the Atlas sustainer. Next came filters to measure the frequency of light emissions from Earth’s atmospheric airglow, followed by star navigation cards, worldwide orbital and weather charts and bags of food.

Orienting the capsule such that the sustainer was dead-centre in his window, Carpenter reported to the Canaries ground station that he could see ‘‘west of your station, many whirls and vortices of cloud patterns’’. His view of the heavens was somewhat less clear, with the stars too dim to make out against the black sky, although the Moon and terrestrial weather patterns were obvious. Then, 16 minutes after launch, the astronaut noted that his spacecraft’s actual attitude did not seem to be in agreement with what the instruments were telling him. Aware of problems that John Glenn had experienced with his gyro reference system, and cognisant of the fact that he had other work to do, Carpenter dismissed it.

“A thorough check, early in the flight, could have identified the [pitch horizon scanner] malfunction,” he later wrote. “Ground control could have insisted on it, when the first anomalous readings were reported. Such a check would have required anywhere from two to six minutes of intense and continuous attention on the part of the pilot. A simple enough matter, but a prodigious block of time in a science flight – and in fact the very reason [such] checks weren’t included in the flight plan.’’ With so much to do, it would not be until his second orbit that Carpenter would again report problems with the autopilot.

Passing over the ground station at Kano, in north-central Nigeria, Carpenter successfully photographed the Sun for physicists at the Massachusetts Institute of Technology, then, over the Indian Ocean, acquired initial readings for John O’Keefe’s airglow study. However, conditions aboard the spacecraft were becoming uncomfortable, as the cabin temperature increased. Years later, in ‘The Right Stuff’’, Tom Wolfe would describe Aurora 7 as ‘‘a picnic’’ and that its astronaut had ‘‘a grand time’’; Carpenter, however, countered that his lengthy training as Glenn’s backup and shorter-than-normal preparation for his own mission made it anything but a walk in the park. ‘‘To the extent that training creates certain comfort levels with high-performance duties like spaceflight,’’ he wrote, ‘‘then, yes, I was prepared for, and at times may have even enjoyed, some of my duties aboard Aurora 7. But I was deadly earnest about the success of the mission, intent on observing as much as humanly possible, and committed to conducting all the experiments entrusted to me. I made strenuous efforts to adhere to a very crowded flight plan.’’

Admirably, for the first 90 minutes of his mission, Carpenter focused on his Earth-observation tasks, photographing rapid changes in light levels as the spacecraft crossed the ‘terminator’ – the dividing line between the darkened and sunlit sides of Earth – and expressing sheer astonishment as the Sun disappeared below the horizon. ‘‘It’s now nearly dark,’’ he remarked in the flight transcript, ‘‘and I can’t believe where I am!’’ Passing over Muchea in Australia, Carpenter discussed with Capcom Deke Slayton possible ways of establishing attitude control on the dark side of Earth with no moonlight and relayed what reliable visual references he had through the window or the periscope. Pitch attitude was not a problem, thanks to scribe reference marks on Aurora 7’s window, but accomplishing the correct yaw angle was much more difficult and time-consuming.

‘‘At night, when geographic features are less visible, you can establish a zero-yaw attitude by using the star navigation charts, a simplified form of a slide rule,’’ Carpenter wrote. ‘‘The charts show exactly what star should be in the centre of the window at any point in the orbit – by keeping that star at the very centre of your window, you know you’re maintaining zero yaw. But there are troubles even here, for the pilot requires good ‘dark adaption’ to see the stars and dark adaption was difficult during the early flights because of the many light leaks in the cabin.’’ Among the most annoying of these leaks were Aurora 7’s instrument panel lights and, particularly, the glowing rim around the spacecraft’s on-board clock. Carpenter told Slayton that his pressure suit’s temperature was higher than normal, before crossing over the Woomera tracking station, with the intention of observing four flares of a combined one million candlepower, fired from the Great Victoria Desert as a visibility check. To see the flares, Carpenter was required to undertake “a whopping plus-80 degrees yaw manoeuvre and a pitch attitude of minus-80 degrees’’, but, unfortunately, cloud cover was too dense. “No joy on your flares,’’ he told Woomera.

Another aspect of the mission about which no joy was forthcoming was the multi­coloured balloon, which he released an hour and 38 minutes after launch. For a few seconds, the expected ‘confetti spray’ signalled a successful deployment, but it soon became clear that the balloon had not inflated properly. Due to a ruptured seam in its skin, it deployed to a third of its expected size and only two of its five colours – Day-Glo orange and dull aluminium – were visible. Two small, ear-like appendages, each about 15-20 cm long and described as ‘‘sausages’’, emerged on the edges of the partially-inflated sphere. Its movements turned out to be erratic and, although Carpenter succeeded in acquiring a few drag-resistance measurements, the 30 m tether quickly wrapped itself around Aurora 7’s nose. Consequently, the aerodynamic data was of limited use. Carpenter attempted to release the balloon during his third orbit, whilst flying over Cape Canaveral, but it remained close to the spacecraft. There it stayed until retrofire and eventually burned up during re-entry.

By this time, Mission Control was keeping a close eye on Aurora 7’s fuel usage, which, by two hours into the flight, was at the 69-per cent capacity for both its manual and automatic supplies. As Carpenter passed over Nigeria early in his second orbital pass, the manual supply had dropped still further to just 51 per cent. He told the Kano capcom that he felt he had expended additional fuel trying to orient the spacecraft whilst on the dark side and blamed “conflicting requirements of the flight plan’’. During each fly-by-wire manoeuvre, very slight movements of the control stick would activate the small thrusters, whereas bigger movements would initiate larger thrusters. For every accidental flick of his wrist, Carpenter could activate the larger thrusters and would then have to correct them, thus wasting valuable fuel. ‘‘The design problem with the three-axis control stick, as of May 1962,’’ he wrote later, ‘‘meant the pilot had no way of disabling, or locking-out, these high-power thrusters.’’ Subsequent Mercury flights would employ an on-off switch for just that purpose.

The still-unknown problem with the pitch horizon scanner, though, remained. A little over two hours into the mission, the Zanzibar capcom informed Carpenter that, according to the flight plan, he should now be transitioning Aurora 7 from automatic to fly-by-wire controls. The astronaut opposed this, preferring to remain in automatic mode, which was supposedly more economical with fuel consumption. Unfortunately, this proved not to be the case, because the malfunctioning pitch horizon scanner was feeding incorrect information into the autopilot, which, in turn, was guzzling far more fuel than it should. A few minutes later, in communication with a tracking ship in the Indian Ocean, Carpenter reported difficulties with the automatic control mode and switched to fly-by-wire in an effort to diagnose the problem.

Although a malfunctioning automated navigational system in orbit was tolerable, its satisfactory performance was essential for retrofire to ensure that the spacecraft was properly aligned along the pitch and yaw axes to begin its fiery descent through the atmosphere. “Pitch attitude … must be 34 degrees, nose-down,” wrote Carpenter. “Yaw, the left-right attitude, must be steady at zero degrees, or pointing directly back along flight path. The [autopilot] performs this manoeuvre automatically, and better than any pilot, when the on-board navigational instruments are working properly.” Sadly, on Aurora 7, they were not. The astronaut could align his capsule manually, but with difficulty: by either pointing the nose in a direction that he thought was a zero-degree yaw angle and then watching the terrain pass beneath him (considered near-impossible over featureless terrain or ocean) or use a certain geographical feature or cloud pattern for reference.

“Manual control of the spacecraft yaw attitude using external references,” he wrote later, “has proven to be more difficult and time-consuming than pitch and roll alignment, particularly as external lighting diminishes… Ground terrain drift provided the best daylight reference in yaw. However, a terrestrial reference at night was useful in controlling yaw attitudes only when sufficiently illuminated by moonlight. In the absence of moonlight, the pilot reported that the only satisfactory yaw reference was a known star complex nearer the orbital plane.”

Carpenter had other worries, too. His cabin and pressure suit temperatures were climbing to uncomfortable levels; the former, in fact, peaked at 42°C during his third orbit, while the latter rose to 23.3°C and a “miserable” 71 degrees of humidity. The capcom’s query as to whether the astronaut felt comfortable, having fiddled with his suit’s controls, was greeted with a non-committal “I don’t know”. After the flight, the high cabin temperatures were attributed to the difficulty of achieving high air­flow rates and good circulation, as well as the vulnerability of the spacecraft’s heat exchanger to freezing blockage when high rates of water flow were used. Meanwhile, Carpenter was also required to take frequent blood pressure readings, pop xylose pills for post-flight urinalysis and monitor each of his scientific experiments. He did also manage to eat solid food during the mission: the Pillsbury Company had prepared chocolate, figs and dates with high-protein cereals, whilst Nestle provided some ‘bonbons’, composed of orange peel with almonds, high-protein cereals with almonds and cereals with raisins. These had been processed into particles a couple of centimetres square and were coated with edible glazes. The astronaut sampled them, but found them to crumble badly, leaving pieces floating around the cabin.

He succeeded in shooting photographs of the Sun for the Massachusetts researchers, acquired photometric readings on the star Phecda (more formally, Gamma Ursae Majoris) and his work on the liquid-behaviour experiment showed that capillary action could indeed pump fluids in space. However, he also reported worrying decreases in his fuel, which had hit just 45 per cent in the case of the manual supply. Indeed, Flight Director Chris Kraft, writing in his post-flight report on Aurora 7, would comment that the mission had run smoothly thus far, with the exception of the ‘‘over-expenditure of hydrogen peroxide fuel’’. At this point, Kraft felt that sufficient fuel remained to achieve the retrofire attitude, hold it steady and re-enter the atmosphere with either the automatic or manual control systems.

In his autobiography, Carpenter suggested that Kraft’s frustration with him began to emerge at this point, the flight director having apparently concluded that the astronaut had deliberately ignored a request to conduct an attitude check over Hawaii. Kraft also voiced serious concerns to California capcom Al Shepard that Carpenter was to tightly curb his automatic fuel use prior to retrofire. By this time, Aurora 7 was restricted to long periods of drifting flight, with both automatic and manual fuel quantities now dropping to less than 50 per cent. Years later, Gene Kranz would blame ground controllers for waiting too long before addressing the fuel status and felt that they should have been more dogged and forceful in getting on with the checklists. “A thoroughgoing attitude check, during the first orbit,’’ added Carpenter, “would probably have helped to diagnose the persistent, intermittent and constantly varying malfunction of the pitch horizon scanner. By the third orbit, it was all too late.’’ Whilst drifting, Carpenter beheld one of the most spectacular sights of the mission: his final orbital sunrise, witnessed four hours and 19 minutes after launch, shortly before retrofire. “Stretching away for hundreds of miles to the north and the south,’’ he wrote, sunrise presented “a glittering, iridescent arc’’ of colours, which faded into a purplish-blue and blended into the blackness of space.

This blackness, he would write in his post-flight report, together with brilliant shades of blue and green from the sunlit Earth, were “colours hard to imagine or duplicate because of their wonderful purity. Everywhere the Earth is flecked with white clouds’’. The South Atlantic, he recounted, was 90 per cent cloud-covered, but western Africa was completely clear and Carpenter was granted a stunning view of Lake Chad. He spotted patchy clouds over the Indian Ocean, a fairly clear Pacific and an obscured western half of Baja California. He described the atmospheric airglow layer in detail to Slayton when he came within range of Muchea. “The haze layer is very bright,’’ he reported. “I would say about eight to ten degrees above the real horizon. . . and I would say that the haze layer is about twice as high above the horizon as the bright blue band at sunset is.’’

His long period of drifting flight also meant that he had the opportunity to witness the ‘fireflies’ seen by John Glenn three months earlier. By rapping his knuckles on the inside walls of the spacecraft, he could raise a cloud of them and determined that they came from Aurora 7 itself. ‘‘I can rap the hatch and stir off hundreds of them,’’ he reported. To Carpenter, they appeared more like snowflakes and did not seem to be ‘luminous’, actually varying in size, brightness and colour. Some were grey, some white and one in particular, he said, looked like a helical shaving from a lathe. Carpenter then decided, with only minutes remaining before retrofire, to yaw the spacecraft in order to get a better view with the photometer. Shortly thereafter, he passed over Hawaii, whose capcom told him to reorient Aurora 7, go to autopilot and begin stowing equipment and running through pre – retrofire checklists.

More problems arose. Four hours and 26 minutes after launch, with retrofire barely six minutes away, Carpenter reported that the automatic system did not appear to be working properly and confirmed that the ‘‘emergency retro-sequence is armed and retro manual is armed’’. In his autobiography, he would recount that the autopilot was not holding the spacecraft steady and, indeed, that achieving the correct pitch and yaw attitudes were critical to ensuring that he would descend along a pre-determined re-entry flight path and plop into the waters of the Atlantic, just south-east of Florida. Carpenter promptly switched to the fly-by-wire controls, but forgot to shut off the manual system, which wasted even more fuel. At around the same time, two fuses overheated and the astronaut noticed smoke drifting through the cabin.

Concerned that the critically-timed retrofire would now be delayed by the autopilot malfunction, Carpenter initiated it manually. He fired the rockets three seconds late, but admitted later “at that speed, a lapse of three seconds would make me at least 15 miles ‘long’ in the recovery area”. Although he radioed to Shepard that he felt his spacecraft attitudes were good, privately, Carpenter was not sure and added, almost as an afterthought, that ‘‘the gyros are not quite right’’. Years later, he would describe the difficulty in dividing his attention between two attitude reference systems and attempting to accomplish a perfect retrofire. ‘‘It appears I pretty much nailed the pitch attitude,’’ he wrote, ‘‘but the nose of Aurora 7, while pitched close to the desirable negative 34 degrees, was canted about 25 degrees off to the right, in yaw, at the moment of retrofire. By the end of the retrofire event, I had essentially corrected the error in yaw, which limited the overshoot. But the damage was already done.’’

The 25-degree cant alone would have caused Aurora 7 to miss its planned splashdown point by around 280 km; however, the three-second delay in firing the retrorockets and a thrust decrement – some three per cent below normal – contributed an additional 120 km to the overshoot. On the other hand, if Carpenter had not bypassed the autopilot and manually fired the retrorockets, he could have splashed down even further off-target. At this stage, his fuel supplies were holding at barely 20 per cent for manual and just five per cent for automatic. Carpenter survived re-entry, but experienced a wild ride back through the atmosphere, with Aurora 7 oscillating between plus and minus 30 degrees in pitch and yaw. The astronaut was able to damp out many of these oscillations with the fly-by-wire controls and the post-flight report would commend him as having ‘‘demonstrated an ability to orient the vehicle so as to effect a successful re-entry’’. It provided clear evidence that a human pilot could overcome malfunctioning automatic systems.

Carpenter’s descent and the trapezoidal window offered a spectacular view of Earth, zooming towards him. ‘‘I can make out very small farmland, pastureland below,’’ he reported, some four hours and 37 minutes after launch. ‘‘I see individual fields, rivers, lakes, roads, I think.’’ Five minutes later, Gus Grissom, the Florida capcom, informed him that weather conditions in the anticipated recovery zone were good. By this time, shortly before ionised air surrounding the capsule caused a communications blackout at an altitude of around 22 km, Carpenter began to see the first hints of an intense orange glow as particles from the ablative heat shield formed an enormous ‘wake’ behind him. Then came distinct green flashes, which the astronaut assumed were the ionising beryllium shingles on Aurora 7’s hull. As the re­entry G forces peaked at 11 times their normal terrestrial load, telemetred cardiac readings at Mission Control revealed the substantial physical effort needed by

Carpenter to speak, announce observations and make status reports. His breathing technique, perfected in the Johnsville centrifuge, would come in useful.

Five minutes before splashdown, at an altitude of 7.6 km, he manually deployed the drogue parachute, which steadied the capsule and damped out what he had earlier described as “some pretty good oscillations”. The drogue was soon followed by the main chute, again manually deployed, although Carpenter’s announcements of each milestone over the radio to Grissom fell on deaf ears. The capcom could not hear his transmissions and was forced to broadcast ‘in the blind’ to inform him that his splashdown point would be some 400 km ‘long’ and advise that pararescue forces would arrive on the scene within the hour. A minute before splashdown, Carpenter acknowledged Grissom’s call. The impact with the water, 215 km north-east of Puerto Rico, was not hard, but Aurora 7 was totally submerged for a few seconds. It popped back up and listed sharply, 60 degrees over to one side, before the landing bag filled and began to act as a sea-anchor.

Keen to get out as soon as possible and probably thinking back to Grissom’s own misfortune, Carpenter opted to exit the capsule through the nose, becoming the first and only Mercury astronaut to do so. It took him four minutes and required him to remove the instrument panel from the bulkhead, exposing a narrow egress passage up through the spacecraft’s nose, where the two parachutes had resided. As he squirmed his way through the cramped space, Carpenter decided, in defiance of standard egress procedures, not to deploy his pressure suit’s neck dam. He was already overheating and felt the gently swelling seas would make it unnecessary. Next, still perched in the nose of the capsule, he dropped his life raft into the water, where it quickly inflated and a Search and Rescue and Homing (SARAH) beacon came on automatically. The latter would allow recovery forces to home in on his position.

Preparing himself for a long wait, Carpenter tied the raft to the side of the capsule, deployed his neck dam, said a brief prayer and relaxed. He stretched out on his raft and was joined, he wrote later, by ‘‘a curious, 18-inch-long black fish who wanted nothing more than to visit’’. It was his first physical contact with another living being and his first moment of calm in four hours and 56 minutes since launch.

For those watching the mission from afar, however, there was no relaxation. At Cape Canaveral, CBS anchorman Walter Cronkite played up the drama by describing for his audience Mission Control’s repeated attempts to contact Aurora 7, then highlighted that Carpenter had endured ‘‘half a ton’’ of pressure during re-entry and finally recapped that flight controllers were still ‘‘standing by’’ after losing voice contact with the astronaut. ‘‘While thousands watch and pray,’’ Cronkite told his audience, ‘‘certainly here at Cape Canaveral, the silence is almost intolerable.’’ In Manhattan’s Grand Central Terminal, a hush fell over the crowd gathered before a huge CBS screen, while in the White House a direct telephone link with the Cape had been set up to provide President Kennedy with news. In fact, the SARAH beacon had already given Carpenter’s co-ordinates and his telemetred heartbeat had been clearly heard in Mission Control throughout re-entry. Moreover, his splashdown point was almost exactly where the IBM computers at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, had predicted him to be after factoring-in radar tracking data and the yaw error at the point of retrofire.

Aboard the destroyer John R. Pierce – nicknamed the ‘Fierce Pierce’ – the attitude was quite different thanks to the reception of the strong SARAH signal. ‘‘Believe you me,’’ reported CBS journalist Bill Evenson from aboard the destroyer, ‘‘this bucket of bolts is really rolling now and what a happy crew we’ve got!’’

It was a Lockheed P2V Neptune, one of the same breed of patrol aircraft that Carpenter had flown a decade earlier in Korea, which finally greeted him. The astronaut signalled the pilot with a hand mirror and was acknowledged when the Neptune began circling his position. Shorty Powers, upon hearing the news, announced that ‘‘a gentleman by the name of Carpenter was seen seated comfortably in his life raft’’. One hour and seven minutes after splashdown, at 1:48 pm Eastern Standard Time, Airman First Class John Heitsch and Sergeant Ray McClure from an SC-54 transport aircraft joined the astronaut in the water, opened their rafts and tethered them together. Carpenter offered them some of his food rations, which were politely declined. Eventually, the astronaut was picked up by the Intrepid, originally earmarked as the prime recovery ship, but delayed in its arrival by Aurora 7’s 400 km overshoot. The Fierce Pierce, meanwhile, successfully recovered the spacecraft itself and delivered it, on 28 May, to Roosevelt Roads in Puerto Rico.

Carpenter, meanwhile, was hot and wet after almost an hour on his back on the launch pad, followed by five hours in space and more than an hour in the Atlantic. Soon after boarding the rescue helicopter, he borrowed a pocket knife, cut a hole in the sock of his pressure suit and let his sweat and seawater drain out of the makeshift toe hole. Army physician Richard Rink asked Carpenter how he felt. In true Mercury Seven fashion, perfectly demonstrative of the ‘right stuff’ about which Tom Wolfe would later write, America’s fourth man in space replied simply: ‘‘Fine’’.

By the middle of 1963, shortly after Faith 7, Shepard’s chances of commanding the first Gemini looked bright. Then his career and health, figuratively and literally, started spinning. Years earlier, just after being selected as one of the Mercury Seven, he had complained about feeling light-headed during a game of golf; every time he attempted to swing the club, he felt that he was about to fall over. It was an isolated, peculiar incident, which did not resurface again until the summer of 1963. It came with a vengeance, usually striking him in the mornings and taking the form of a loud metallic ringing in his ears, coupled with feelings of intense dizziness and nausea. At first, Shepard dealt with the problem himself: he saw a private physician, who prescribed diuretics and vitamins such as niacin, which had little effect. It did not stop Slayton from assigning him to command Gemini 3 and, indeed, Shepard and Stafford completed the first six weeks of their training, visiting McDonnell’s St Louis plant in Missouri to watch their spacecraft being built.

He told no one in the astronaut corps of the problem. However, very soon, it became impossible to conceal. An episode of dizziness whilst delivering a lecture in Houston forced him to admit his concerns to Slayton, who sent him to the astronauts’ physician, Chuck Berry, for tests. In May 1963, unknown to everyone else in the corps, Shepard was temporarily grounded. The diagnosis was that fluids were regularly building up in the semicircular canals of his inner ear, affecting his sense of balance and causing vertigo, nausea, hearing loss and intense aural ringing. Although the incidents were intermittent, they proved sufficiently unpredictable and severe to render him ineligible to fly Gemini 3.

Known as Meniere’s Disease, the ailment was a recognised but somewhat vague condition. Indeed, formal criteria to define it would not be established by the American Academy of Otolaryngology-Head and Neck Surgery until 1972. The academy’s criteria would describe exactly the conditions suffered by Shepard:

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fluctuating, progressive deafness – he would be virtually deaf in one ear by 1968 – together with episodic spells of vertigo, tinnitus and periodic swings of remission and exacerbation. Nowadays, it can be treated through vestibular training, stress reduction, hearing aids, low-sodium diets and medication for the nausea, vertigo and inner-ear pressure: such as antihistamines, anticholinergics, steroids and diuretics. In mid-1963, however, the physicians who examined Shepard had next to no idea what caused it, some speculating that it was a ‘psychosomatic’ affliction. Moreover, there was no cure.

His removal from flight status was temporarily revoked in August, with the prescription of diuretics and pills to increase blood circulation, in the 20 per cent hope that the condition would clear up on its own. This allowed Shepard to be internally assigned to Gemini 3, but when the early diagnosis was confirmed and no sign of improvement was forthcoming, he was formally grounded in October, after only six weeks of training with Stafford. During those weeks, the men had spent some time in the Gemini simulator, but little more. Not only was Shepard barred from spaceflight, but, like Deke Slayton, he also could not fly NASA jets unless accompanied by another pilot. Subsequent examinations revealed that he also suffered from mild glaucoma – a symptom of chronic hyperactivity – and a small lump was discovered on his thyroid. It was surgically removed in January 1964 and, the press announced, ‘‘would have no impact on his status in the space programme’’. In reality, Shepard had been effectively grounded for months by that point.

Ironically, at the same time, John Glenn, who had resigned from NASA after being told that his chances of flying again were slim, suffered damage to his own vestibular system. Glenn’s friendship with Attorney-General Bobby Kennedy had led to the first inkling of a political career and, after leaving the astronaut corps in January 1964, he announced his candidacy to run for the Senate in his home state of Ohio. A few weeks later, he slipped and cracked his head on the bathtub in his apartment, resulting in mild concussion and, more seriously, swelling in his inner ear, which produced similar symptoms to Meniere’s Disease. Glenn spent several weeks in a San Antonio hospital, virtually immobile, and was forced to withdraw from the Senate race in March.

Elsewhere, at the Rice Hotel in downtown Houston, Shepard pulled Stafford aside one evening that same March and asked him if Slayton had mentioned anything about the Gemini 3 assignment. No, Stafford replied, and could only listen open-mouthed as his former crewmate told him about the dizziness, the vertigo, the Meniere’s diagnosis. . . and the bombshell that Shepard was grounded. In his autobiography, Stafford recalled fearing for his own place on Gemini 3, and, indeed, in mid-April, the crew changes were announced. Slayton moved Gus Grissom up from the command slot on Gemini V to lead Shepard’s old mission and replaced him with Gordo Cooper, who had established himself as capable of enduring a long – duration flight on Faith 7. Unluckily for Stafford, however, Slayton felt that John Young was a better personality match with Grissom and designated him as Gemini 3’s new pilot. He had nothing against Stafford, of course, simply revealing in his autobiography that ‘‘Tom was probably our strongest guy in rendezvous, so it made sense to point him at [Gemini VI], the first rendezvous mission’’.

Stafford learned of his removal from the Gemini 3 prime crew from one of the flight surgeons, Duane Ross, who told him that he was now on Gus Grissom’s backup team, paired with Wally Schirra. Grissom’s original pilot, Frank Borman, would be “held for later’’ and another mission. In his biography of Grissom, Ray Boomhower cited fellow astronaut Gene Cernan as remarking that Grissom’s and Borman’s egos – both of them were strong-headed leaders – were too large to fit one mission. Indeed, in an April 1999 oral history for NASA, Borman hinted that he “went over to [Grissom’s] house to talk to him about it … and after that I was scrubbed from the flight’’. Borman, eventually, would command his own Gemini. Meanwhile, on 13 April 1964, the four-man unit for Gemini 3 set to work. Only days earlier, the first unmanned test to assess the compatibility of the spacecraft and its launch vehicle had proven a remarkable success. It came after almost three years of technical and managerial difficulties and a development programme laced with problems.

To this day, Gherman Stepanovich Titov remains the youngest person ever to have flown into space, a record he has held for almost five decades. On 6 August 1961, he was just a month shy of his 26th birthday. Born on 11 September 1935, he was named Gherman – an unusual name for a Russian – by his father, in honour of a favourite Pushkin character from ‘The Queen of Spades’. Titov’s own love of literature, though, went far beyond the inspiration for his name: in his cosmonaut days, he was well-known for quoting long reams of poetry or fragments from stories or novels. Jamie Doran and Piers Bizony have hinted that, in the “egalitarian workers’ and peasants’ paradise’’ that was the old Soviet Union, this may have harmed his chances of becoming the first man in space. Unlike Pushkin, whose liberal views and influence on generations of Russian rebels led the Bolsheviks to consider him an opponent to bourgeois literature, Titov’s pride, love of poetry and reading and a ‘‘suspicion of class’’ bestowed on him by his learned father made him somewhat less appealing to Nikita Khrushchev’s regime than Yuri Gagarin.

His breakthrough to reach the hallowed ranks of the first cosmonaut team in March 1960 came about through his excellence as a MiG fighter pilot. Titov had entered the Ninth Military Air School at Kustanai in Kazakhstan in 1953, transferring to the Stalingrad Higher Air Force School two years later, where he commenced military flight training. Following qualification, in September 1957 he was attached to two different Air Guard regiments in the Leningrad Military District and subsequently became a Soviet Air Force pilot in the Second Leningrad Aviation Region. His selection as a cosmonaut, he would recall more than three decades later, was almost a fluke, with the answers he gave to the physicians and psychologists bordering on arrogance. He seemed non-committal in his interviews even when the subject of ‘‘flying sputniks’’ in orbit was broached. However, he said, ‘‘I was curious about how it would be to fly a sputnik and I was told that I had been called to Moscow. I went to Moscow and I was enrolled into the cosmonauts’ team’’.

Titov’s selection was lucky in another way, too. At the age of 14, he had crashed his bicycle and shattered his wrist. Instead of revealing the injury to his parents, he nursed it secretly, unwilling to show any sign of weakness, particularly as he had already signed up for elementary training at aviation school. During his time as a cadet, fearful that his injury would be discovered, Titov bluffed them by performing early-morning exercises on a set of parallel bars, until his damaged wrist appeared as good as the other. When he underwent intensive X-rays for the cosmonaut selection in 1960, the medical staff found nothing amiss. Only years after his Vostok 2 flight, when they learned of the injury, did they tell him that his recruitment would never have been sanctioned if they had known.

As Kennedy battled through the closing months of his election campaign, NASA battled with similar tenacity and vigour to launch the first man into space. Many in the United States, however, were already echoing Louise Shepard’s sentiment that the Soviets remained in pole position to accomplish the historic feat. Project Mercury, Time magazine told its readers in September I960, “is not far behind, but it will be at least nine months before a US astronaut will enter orbit’’. ‘Orbit’ would prove the pivotal point, for neither America’s first man in space, nor even its second, would achieve orbit – they would experience little more than 15-minute suborbital arcs over the Atlantic Ocean, into space and back down – and the nation’s first piloted circuit of the globe would not come until February 1962. Still, in the weeks after Kennedy’s inauguration, Al Shepard and John Glenn were dividing their time between Langley Research Center in Virginia and the swamp-fringed Cape Canaveral launch site in Florida, familiarising themselves with ‘Spacecraft No. 7’: the vehicle which, since October of the previous year, had been earmarked for the first mission.

Unlike the huge spherical Vostok which had ferried Yuri Gagarin into space, the Mercury capsule was a cone-shaped machine, 1.9 m across the blunt, ablative heat shield at its base and 2.9 m tall, with a total habitable volume of just 1.6 m3 and an approximate weight at launch of 1,930 kg. The idea that a blunt cone was the most suitable shape to prevent a rocket-carried warhead from burning up in the atmosphere had arisen in the early Fifties, thanks to the work of NACA engineers Julian Allen and Al Eggers. Attached to its nose was a cylindrical parachute compartment and at its base a cylindrical package of three retrorockets. Its cramped nature prompted the astronauts to smirk that, far from ‘flying’ the spacecraft they actually ‘wore’ it. ‘‘You get in with a shoehorn,’’ added McDonnell’s pad leader Guenter Wendt, ‘‘and get out with a can opener!’’ During the early stages of ascent, capsule and astronaut would be protected by a pylon-like, solid-fuelled Launch Escape System (LES), capable of whisking them away from an exploding or malfunctioning rocket. This measured 5.15 m tall and produced 23,580 kg of thrust. Under normal circumstances, however, it was intended that the LES would be jettisoned shortly after the burnout of the rocket, although many engineers doubted its effectiveness and felt that a catastrophic failure would give an astronaut little chance of survival.

The Mercury capsule was equipped with attitude-control thrusters to enable yaw, pitch and roll exercises, but was incapable of actually changing its orbit. The three solid-fuelled retrorockets provided an ability to return to Earth, firing in sequence at five-second staggered intervals, in a ‘ripple’ fashion, although one was sufficient to complete this task if the others failed. To guard against temperatures as high as 5,200°C at its base during re-entry, a heat shield composed of fibreglass, bonded with a modified phenolic resin, was employed. By charring, melting and peeling off, taking heat with it, this ‘ablative’ material would protect the structure of the spacecraft from the high heat flux of hypersonic re-entry into the atmosphere. It was first tested atop an Atlas rocket in September 1959, surviving re-entry in remarkably good condition. The heat shield was not, in fact, an integral part of the spacecraft, but was held in place by a series of hooks. Between it and the base of the capsule was a folded rubber-and-glass-resin ‘landing bag’, 1.2 m deep, which would unfold and fill with air shortly before splashdown in the ocean. This would act as an absorber,

softening the shock of landing from 45 G to 15 G, before filling with water to provide a kind of ‘sea-anchor’.

Mercury was the brainchild of NACA aerodynamicist Max Faget, adapted from Allen and Eggers’ blunt-cone design, and received the go-ahead on 7 October 1958, only six days after NASA’s birth. The name arose from that of the fleet-footed messenger of Roman mythology and, wrote Loyd Swenson in ‘This New Ocean’, a seminal 1966 work on Project Mercury, ‘‘seemed too rich in symbolic associations to be denied. The esteemed Theodore von Karman had chosen to speak of Mercury, as had Lucian of Samosata, in terms of the ‘re-entry’ problem and the safe return of man to Earth’’. By mid-January 1958, McDonnell had been awarded the $18.3 million contract to build the spacecraft, beating Grumman, which was heavily loaded with conceptual naval projects at the time. Faget’s original design for a ballistic capsule envisaged that it would re-enter the atmosphere at an attitude 180 degrees from that of launch, such that the G forces would be imposed on the front of the body under acceleration and deceleration; in effect, its ‘tail’ during launch would become its ‘nose’ during the journey back to Earth. Initial sketches from late 1957 revealed a squat, domed body with a nearly flat heat shield, the former slightly recessed from the perimeter of the latter, leaving a narrow ‘lip’ to deflect airflow and minimise heat transfer. However, this configuration proved dynamically unstable at subsonic speeds, so Faget’s group lengthened the capsule and removed the heat shield lip.

By March of the following year, the design resembled an elongated cone, which provided dynamic stability, but hypersonic wind tunnel tests showed that too much heat would be transferred by turbulent convection. Further, engineers could not figure out how to incorporate parachutes into the upper part of the nosecone, prompting its redesign into a rounded shape with a short cylinder attached to the top. Heat-transfer concerns, however, remained, and it was not until the late summer that the design, incorporating maximum stability, relatively low heating and a suitable parachute compartment, had been finalised. Faget’s team argued that by launching the capsule on a ballistic trajectory, its automatic stabilisation, guidance and control equipment could be minimised and the only manoeuvre it would be required to make would be to fire the retrorockets to decelerate and dip into the atmosphere for aerodynamic drag. In fact, added Faget, even that manoeuvre did not need to be too precise to accomplish a successful recovery.

In theory, Spacecraft No. 7 – the seventh of 20 Mercury capsules built by McDonnell – should have been capable of flying Shepard almost immediately, but after delivery to Cape Canaveral on 9 December 1960, it became necessary to implement 21 weeks’ worth of unexpected tests, repairs and rework. Additionally, the landing bag, beneath the heat shield, which would cushion its splashdown in the Atlantic Ocean, had to be installed and communications hardware checked. Its reaction-control system needed attention, whilst damaged and corroded hydrogen peroxide fuel lines required replacement and a variety of other obstacles surrounded equipment, minor structural defects and even the need to install a manual bilge pump to remove seawater. The need for the latter had been compounded by the successful, though harrowing, flight of a chimpanzee named Ham. He had been launched atop a Redstone in late January, but his capsule had suffered a multitude of niggling malfunctions. Firstly, a faulty valve had fed too much fuel into the rocket’s engine, causing Ham to fly too high and too far, whereupon the tanks ran dry, the spacecraft separated too early and re-entered the atmosphere too fast and at the wrong angle. Temperatures soared and a glitch ‘rewarded’ Ham not with banana pellets for pulling the right levers and pushing the right buttons, but with electric shocks. At the end of the mission, with the capsule filling with seawater and about to sink, ‘‘a very pissed-off chimp’’ was safely fished from the Atlantic by the recovery forces.

Wernher von Braun, whose team had designed and built the Redstone, feared that Shepard’s mission, then scheduled for March, could be similarly affected and opted for one final unmanned launch. The astronaut, however, pushed NASA officials and even von Braun himself to go ahead with his mission, regardless of the risk, feeling that he could handle and overcome any Ham-type problems. The German stood firm, though, and a nervous NASA stood beside him.

‘‘We were furious,’’ remembered Chris Kraft. ‘‘We had timid doctors harping at us from the outside world and now we had a timid German fouling our plans from the inside.’’ Furthermore, Jerome Wiesner, recently picked by President Kennedy as his science advisor, warned of the harm a dead astronaut could cause the new administration and pressed for another test flight. In addition, having inherited chairmanship of the President’s Science Advisory Committee (PSAC), he convened a panel of experts to assess the situation and recommend whether or not to proceed with Shepard’s launch. After viewing astronauts ‘flying’ in the simulators, whirling in the MASTIF and pulling up to 16 G in the centrifuge, the panel concluded that the manned mission should proceed. Their report, ironically, landed on Kennedy’s desk on the afternoon of 12 April 1961.

By this point, Shepard’s launch had already been postponed until the end of the month and, despite the crushing disappointment of Vostok 1, both he and Glenn continued to train feverishly, rehearsing every second of the 15-minute ‘up-and – down’ mission that would arc 188 km into space and back to Earth, splashing into the Atlantic some 200 km downrange of the Cape. It would be a suborbital ‘hop’: the Redstone, capable of accelerating to around 3,500 km/h, lacked the impulse to deliver Shepard into orbit – an Earth-girdling flight would have to await the Atlas – but the mission would prove to the world that the United States was in the game. Today, wrote Chris Kraft in his foreword to Neal Thompson’s biography of Shepard, it is easy to dismiss it and, when placed alongside Vostok 1, it was insignificant, but in the spring of 1961 it captivated not only America, but the world. ‘‘Add to this the fact that the reliability of a rocket-propelled system in 1961 was not much better than 60 per cent,’’ wrote Kraft, ‘‘and you may begin to have a feel for the anxiety all of us were experiencing.’’

The Redstone itself was a direct descendant of the infamous V-2, used by Nazi Germany with such devastating effect in the Second World War, and had been employed as a medium-range ballistic missile to conduct the United States’ first live nuclear tests during Operation Hardtack in August 1958. It remained operational within the Army until 1964, gaining a reputation as the service’s workhorse and, as a non-military launcher, as ‘Old Reliable’. Initial production, under the auspices of prime contractor Chrysler, had gotten underway at the Michigan Ordnance Missile Plant in Warren, Michigan, in 1952. Meanwhile, the Rocketdyne division of North American Aviation built its Model A-7 engine, Ford Instrument Company supplied its guidance and control systems and Reynolds Metals Company fabricated its fuselage. As a weapon, it could be armed with an atomic warhead with a yield of 500 kilotons of TNT or a 3.75 megaton thermonuclear warhead and, indeed, batteries of Redstones were stationed in West Germany until as late as 1964.

A direct outgrowth of the Redstone was the Jupiter-C intermediate-range ballistic missile, which, some observers believe, could have beaten Sputnik 1 by orbiting an artificial satellite in August 1956, had the political will been there. President Eisenhower’s administration, however, preferred to launch America’s first satellite atop a civilian rocket named Vanguard, rather than with a modified military weapon, and the chance was lost. The Vanguard failed spectacularly in December 1957, exploding on the pad, but less than two months later a Jupiter-C successfully lofted the United States’ first satellite, Explorer 1, into space.

A number of modifications were incorporated into the Redstone from 1959 onwards to complete the metamorphosis from a warhead-laden weapon to a man­rated launch vehicle; its reliability as a tactical missile, though high, was inadequate for an astronaut. Since redesigning it to provide the required assurances could have meant implementing a totally new, expensive and lengthy development programme, it was decided instead to adapt the existing model with only the changes needed for a manned flight. In January 1959, the Army Ballistic Missile Agency (ABMA) received the go-ahead to convert the rocket and, two months later, the Space Task Group requested the implementation of an effective abort system. By June, ABMA had submitted its response and, throughout the remainder of the year and into 1960, the design was finalised and implemented: an automatic system, capable of shutting down the Redstone’s engine and transmitting separation abort signals to the Mercury capsule and its attached LES tower. Had the rocket veered off-course, a range safety officer at the Cape would have had little option but to remotely destroy it. However, a three-second delay existed between the transmission of the abort command and the actual destruction of the Redstone, offering a hair’s breadth of time for the capsule to be pulled clear of the conflagration.

It had long been recognised that some emergencies could develop too rapidly for a mission to be manually aborted and, moreover, the astronaut’s own performance under the dynamic conditions of a launch were not known. During their analysis of this problem, ABMA engineers studied 60 Redstone flights, identifying a huge number of components which could conceivably fail. It would be impractical to accommodate them all. However, the study did find that many malfunctions – loss of attitude control and velocity, a lack of proper combustion chamber pressure in the engine or perhaps power supply problems – led to similar results, thus permitting the inclusion of relatively few abort sensors.

Constructed from aluminium alloy, the single-stage Redstone measured 25.4 m long and weighed 3,720 kg. Ignition of its engine was initiated from the ground and liftoff occurred when approximately 85 per cent of its rated thrust had been achieved. During ascent, carbon jet vanes in the exhaust of its propellant unit, coupled with air rudders, served to control its attitude and stability. Its Model A-7 engine, fuelled by a mixture of ethyl alcohol and liquid oxygen, together with a hydrogen peroxide-fed turbopump, yielded 35,380 kg of thrust and was essentially the same as that used by the military Redstone, although a number of improvements had been implemented for efficiency and safety. The Jupiter-C’s use of a highly-toxic propellant mixture called hydyne had been ruled out in favour of alcohol, although the use of the latter was more erosive of the jet vanes. Engine operations continued until the Redstone had reached a pre-determined velocity, at which stage an integrating accelerometer emitted a signal to initiate shutdown by closing off the hydrogen peroxide, liquid oxygen and fuel valves. As pressures in the thrust chamber decreased, a timer started in the Mercury capsule which triggered its separation from the tip of the Redstone.

Other modifications included lengthened tanks, the walls of which were thickened to handle the increased loads of the capsule and heavier propellant haul, and changes were made to increase the reliability of critical electronic components in the Redstone’s instrument section. Indeed, the entire layout of this section was extensively revamped to accommodate new control and abort systems. The elongated propellant tanks and increased payload weight, however, meant that the rocket tended to become more unstable in the supersonic region of flight, around 90 seconds after liftoff, and necessitated the inclusion of 310 kg of steel ballast. Stringers were also added to the inner skin of the Redstone’s aft section to support the weight of the Mercury capsule. The overall ‘burn time’ of the engine for suborbital launches was shortened by 20 seconds to 143.5 seconds in total, prompting the addition of heat-resistant stainless steel shields for the stabilising fins. Additionally, nitrogen-gas purging equipment was added to the tail to prevent an explosive mixture from accumulating in the engine compartment whilst the Redstone sat on the pad.

The first three unmanned test flights evaluated each of these modifications and the combined performance of both the rocket and the capsule under real mission conditions. The first, named Mercury-Redstone 1 (MR-1), was intended to put the abort system fully through its paces, in addition to achieving the kind of velocities – around Mach 6.0 – that the suborbital astronaut would experience and demonstrating the ability of the capsule to separate satisfactorily from the rocket. A launch attempt on 7 November 1960 was scrubbed due to low hydrogen peroxide pressures in the capsule’s thrusters and was rescheduled for the 21st. At 8:59 that morning, ignition occurred on time, but as the Redstone made to leave the pad, a shutdown signal was initiated. The thrust buildup was sufficient for the rocket to rise 10 cm, before it settled back onto its pedestal. However, the shutdown signal had caused the LES tower to fire, producing huge clouds of smoke which momentarily hid the Redstone from view. Flight Director Chris Kraft, watching the proceedings, was astonished by the tremendous acceleration, thinking it to be the actual liftoff. . . ‘‘but then the smoke cleared and the missile was still there!’’ Wally Schirra described the fiasco as ‘‘a memorable day, especially for someone who likes sick jokes’’.

The rocket swayed slightly, but remained upright and did not explode. Worryingly, though, the LES – which shot 1.2 km high and landed 360 m from

the pad – had not pulled the Mercury capsule clear of the Redstone and, as the shocked flight controllers watched, the drogue parachute popped out of its nose, followed by the main canopy and lastly, accompanied by a green cloud of marker dye, an auxiliary chute. All three fluttered pathetically down onto the pad. The rocket, meanwhile, was left alone as its liquid oxygen and high-pressure nitrogen were drained, its fuel and hydrogen peroxide tanks emptied, its circuits deactivated and its destruct arming devices removed. (Initial suggestions to relieve the pressurised propellant tanks by shooting holes in them with a rifle, thankfully, were squashed.)

“The press had a field day,” Kraft recalled later. “It wasn’t just a funny scene on the pad. It was tragic and America’s space programme took another beating in the newspapers and in Congress.’’ Time magazine bemoaned ‘Lead-Footed Mercury’ and ridiculed Wernher von Braun for downplaying the MR-1 fiasco, although a New York Times journalist urged President-elect Kennedy to persevere.

Investigators would find that the shutdown had been triggered by a ‘sneak’ circuit, created when two electrical connectors in a two-pronged booster tail plug separated in the wrong order. And why did the capsule fail to separate along with the LES? According to NASA’s investigation report, it was because the G load sensing requirements had not been met. Ordinarily, after an engine cutoff, a ten-second timer was initiated and, upon its expiration, was supposed to separate the capsule if acceleration was less than 0.25 G. However, MR-1 had settled back onto the pad before the timer expired and the G-switch, sensing 1 G of acceleration, blocked the separation signal. On-board barostats, meanwhile, properly sensed that the rocket’s altitude was less than 3 km and therefore activated the parachutes. ‘‘Once we realised that the capsule had made the best of a confusing situation and had gone on to perform its duties just as it would have on a normal flight,’’ John Glenn said later, ‘‘we were rather proud of it.’’ However, to avoid a recurrence, a ‘ground strap’ was added to maintain grounding of the vehicle during all umbilical disconnections and changes to the electrical network distributor prevented a cutoff signal from jettisoning future LES towers prior to 130 seconds after liftoff.

The undamaged spacecraft would be recycled and reused on the MR-1A flight just four weeks later. Despite some difficulties with a leakage in the capsule’s high – pressure nitrogen line and a faulty solenoid valve in its hydrogen peroxide system, the mission was launched successfully at 11:15 am on 19 December. Thankfully, the abort system performed as advertised, although a malfunction of the velocity integrator caused the Redstone’s velocity cutoff to occur 78 m/sec higher than planned, thus boosting the capsule 9.6 km above its intended 205 km altitude. Accelerations during re-entry were correspondingly more severe and high tail winds during the final portion of the flight led to MR-1A splashing into the Atlantic 32 km further downrange than anticipated. The source of the velocity integrator problem was traced to excessive torque against the pivot of the accelerometer, caused by electrical wires; five of these were replaced and a softer wire material was implemented. This solved the problem, as the chimpanzee Ham’s MR-2 flight at the end of the following month would demonstrate.

Ham was not the first animal to have been launched by the United States. A pair of Rhesus monkeys, nicknamed ‘Sam’ and ‘Miss Sam’, from the School of Aviation

Medicine in San Antonio, Texas, had been launched atop Little Joe rockets in December 1959 and January I960, respectively. Although neither of their Mercury capsules reached space (Sam achieved an altitude of 88 km, Miss Sam of 15 km), their flights demonstrated that living creatures could survive a launch and return alive. Unfortunately, the flights of the Rhesus monkeys and chimpanzees, though significant, would offer an excuse for some test pilots to heap further ridicule on the Mercury Seven. When asked if he was interested in riding a capsule into orbit, Chuck Yeager had laughed. “It doesn’t really require a pilot,” he said, “and, besides, you’d have to sweep the monkey shit off the seat before you could sit down!’’

Ham – the name was an acronym for the Holloman Aerospace Medical Center, based at Holloman Air Force Base in New Mexico, which prepared him for his mission – was launched at 11:54 am on 31 January 1961. Chosen specifically because of their close approximation to human behaviour, a colony of six chimpanzees, four female and two male, accompanied by 20 medical specialists and handlers from Holloman, had arrived at Cape Canaveral’s Hangar S a few weeks earlier. The chimps were split into two groups to prevent the spread of any contagion and were led through training exercises with the help of Mercury capsule mockups in their compounds. By the end of the month, each of the chimps was somewhat bored, but nevertheless an expert at pulling levels and pushing buttons in the right order, receiving either banana pellets or mild electric shocks for doing the right (or wrong) thing. The day before launch, James Henry of the Space Task Group and Holloman veterinarian John Mosely examined the six chimps and settled on a particularly frisky and good-humoured male as the prime candidate, with a female as his backup. Both were put on low-residue diets, instrumented with biosensors and, early on the 31st, outfitted in their space suits, placed in their contoured couches and taken to the launch pad. With 90 minutes to go, Ham, described as “still active and spirited’’, was inserted inside the MR-2 capsule.

His home for the 16-minute mission boasted a number of significant innovations, including an environmental control system, live retrorockets, a voice communica­tions device and the accordion-like pneumatic landing bag. The latter was attached to the heat shield and shortly before splashdown, the pair would drop 1.2 m, filling with air to help cushion MR-2’s impact. In the water, the deflated landing bag and heat shield were intended to serve as an anchor, keeping the spacecraft upright.

Ham’s liftoff was successful, although his Mercury capsule, programmed to travel 183 km into space and 468 km downrange of the Cape, actually flew 67 km higher and 200 km further downrange than intended. The chimp experienced six and a half minutes of weightlessness and endured 14.7 times the force of normal terrestrial gravity at one point during his re-entry. He survived and seemed to be in good spirits, despite having to wait for several hours before being picked up by the dock landing ship Donner. After splashdown, his heat shield had skipped on the water, bounced against the capsule’s base and punched two holes in the pressure bulkhead. As MR-2 capsized, the open cabin pressure relief valve let in yet more seawater. By the time he was rescued, it was estimated that there was around 360 kg of seawater inside the capsule. Ham, however, seemed in good cheer, gobbling down a pair of apples and half an orange on the recovery ship’s deck.

Post-flight analysis would reveal that the Redstone’s mixture ratio servo control valve failed in its full-open position, causing early depletion of the liquid oxygen supply; consequently, the propellant consumption rate increased, the turbopump ran faster and led to higher thrust, an earlier-than-scheduled engine shutdown and the inadvertent ‘abort’ of the MR-2 spacecraft. Nonetheless, the basic controllability and habitability of Mercury was deemed a success. In the wake of Ham’s flight, the reliability of the booster-capsule combination was reassessed, culminating in an estimated probability of success at somewhere between 78 and 84 per cent. However, many components had been designed to parameters which exceeded those demanded by the Space Task Group and launch operations personnel had devised their own methods which were more conducive to flight success. Taking this into account, the overall reliability of the system was judged at 88 per cent for launch and 98 per cent for the survival of the astronaut. These assurances were confirmed by one final test prior to Shepard’s mission – the Mercury-Redstone Booster Development (MR-BD) flight, launched at 12:30 pm on 24 March.

Although it was doubtful that any of the problems experienced on either MR-1A or MR-2 would have endangered Shepard, had he been aboard, the Space Task Group’s scrupulous attention to reliability meant that all significant outstanding modifications to the Redstone had to be dealt with. Von Braun also invoked one of the original ground rules, which insisted that no manned flight would be attempted until all responsible parties felt assured that everything was ready. Shepard’s mission was fatefully postponed until 25 April. The MR-BD test, meanwhile, was perfect: the Redstone flew flawlessly, with its thruster control servo valve’s closed position adjusted to 25 per cent open and flight sequencer timer changes prevented a recurrence of the problems on Ham’s flight. Control manoeuvres were executed to evaluate the effect of higher-than-normal angles of attack, confirming that the Redstone could withstand additional aerodynamic loads. No attempt was made to separate rocket and capsule and they splashed down together, some eight and a half minutes after launch, before sinking to the bottom of the Atlantic. The success of MR-BD had cleared the way for MR-3 – the first manned mission – to launch.

To help them prepare more effectively for the flight, Shepard and Glenn had, since February, been using a pair of McDonnell-built Mercury simulators for 55-60 hours per week. They went through flight plans together and, indeed, Shepard ‘flew’ more than 120 simulated Redstone launches during this period. As February wore into March, the training became yet more exacting: both men even went through the ritual of their pre-flight medical examinations, just as they would on launch morning, and were instrumented with biosensors and outfitted in their silver pressure suits. A week after Gagarin’s mission, on 19 April, Shepard sat in the actual capsule, atop its Redstone, on Pad 5 at the Cape, with the hatch open, meticulously plodding through each of the procedures he would follow.

By this time, he had nicknamed his tiny spacecraft ‘Freedom 7’ – not, as some observers would hint, in honour of the seven Mercury astronauts, but rather to reflect its status as the seventh capsule off the McDonnell production line. According to assistant flight director Gene Kranz, the name was adopted during the final Freedom 7 training exercises. On later missions, each member of the Mercury Seven

would suffix their own spacecraft with the number as something of a good-luck charm.

By now, the launch was officially scheduled for 7:00 am on 2 May and, in late April NASA timetabled a full dress rehearsal, with Gordo Cooper standing in for Shepard. He duly suited-up, rode the transport van out to the base of Pad 5 and jokingly bawled “I don’t want to go! Please don’t send me!” before being shoved into the elevator. The assembled journalists, apparently, did not appreciate Cooper’s gallows humour and the following morning’s newspapers even went so far as to criticise NASA for its astronaut’s inappropriate horseplay at such a tense moment. Meanwhile, Shepard checked out of a Holiday Inn where he had been staying with his wife, dropped her at the airport and drove to the astronaut quarters in the three – story Hangar S at the Cape. Since they were still required to maintain the official ‘secret’ that the first American in space could be any one of them, Shepard, Grissom and Glenn shared the same air-conditioned quarters, which had been specially decorated for them by their nurse, Dee O’Hara.

The heavens opened to heavy rain and storms early on 2 May, as the trio arose and ate a breakfast of bacon-wrapped filet mignon and scrambled eggs, together with orange juice and coffee. Since defecation in the spacecraft was, at best, difficult, such ‘low-residue’ launch-morning diets had been enforced by NASA. (Indeed, the astronauts’ lawyer and agent, Leo D’Orsey, when told about the diet, had exclaimed ‘‘No shit?’’ Shepard responded with a grin, ‘‘Exactly!’’)

The intention was that the public ‘final choice’ of who was to fly would be made that morning, with some officials even suggesting bringing all three men out of their quarters wearing hoods to keep the charade going until one of them boarded the Pad 5 elevator. Shepard, wrote Neal Thompson, opposed this lunacy and opted instead to emerge from Hangar S in his pressure suit and wade through the teeming journalists. It made little difference: the rain was so bad that the launch was scrubbed, although not before the identity of America’s first astronaut became known to the newsmen. ‘‘An alert reporter standing by the hangar door,’’ wrote Gene Kranz, ‘‘had seen him and broke the story. The secret was out.’’

Originally planned as a 48-hour postponement, it was soon realised that an attempt early on 4 May would be impossible, so foul was the weather. However, at 8:30 that night, the two-part, ten-hour-long countdown began for a launch the following morning. The stunted nature of this countdown owed itself to past experience, which showed that it was preferable to run it in two short segments to permit the launch crews responsible for both Freedom 7 and the Redstone to be adequately rested and ready. A built-in hold of some 15 hours was called when the clock hit T-6 hours and 30 minutes, during which time various pyrotechnics were installed into the capsule and the hydrogen peroxide system to feed Freedom 7’s thrusters was serviced. The countdown resumed at 11:30 pm and proceeded smoothly until another hour-long built-in hold at T-2 hours and 20 minutes, intended to check that all preparations had been made before Shepard’s departure for the launch pad.

The situation within Mission Control, Deke Slayton recounted, was far from fine. Slayton had been stationed throughout Aurora 7’s flight at the capcom’s mike at the Muchea tracking site in Australia, which he described as ‘‘a good place to be, all things considered’’. Flight Director Chris Kraft and many other mission controllers were furious, accusing Carpenter of having recklessly endangered himself during a botched re-entry. Their anger was exacerbated when, aboard the recovery ship, the astronaut off-handedly remarked that ‘‘I didn’t know where I was… and they didn’t know where I was, either’’. Retrofire controller John Llewelyn is said to have retorted: ‘‘Bullshit! That son-of-a-bitch is damned lucky to be alive!’’

Kraft, apparently, was considerably more caustic. In his autobiography, he wrote of Carpenter’s ‘‘cavalier dismissal of a life-threatening problem’’ – the failure of the spacecraft’s navigational instruments – and troublesome re-entry and swore that the astronaut would never fly again. Carpenter was never assigned another mission, not even in a backup role. After a month-long tour in the Navy’s Sealab-II underwater habitat, off the coast of La Jolla, California, he would resign from NASA early in 1967. Some have seen Carpenter’s mistakes and omissions and his forgetting to do certain critical tasks as evidence that the early Mercury flights were simply too overloaded with experiments and manoeuvres and, further, that Mission Control was at least partly to blame for failing to identify the pitch horizon scanner malfunction for what it was. Tom Wolfe, for his part, later wrote that any speculation that Carpenter had panicked made no sense “in light of the telemetred data concerning his heart rate and his respiratory rate”.

Psychologist Bob Voas weighed in with his own judgement: “The astronaut’s eye on the horizon was the only adequate check of the automated gyro system,’’ he told Carpenter and Kris Stoever. “With its malfunctioning gyros, the spacecraft could not have maintained adequate control during retrofire. Mercury Control may have viewed the manually controlled re-entry as sloppy, but the spacecraft came back in one piece and the world accepted the flight for what it was: another success.’’

Aurora 7, though harrowing, was certainly viewed as a success by Carpenter’s family and hundreds of thousands of residents of his home state, Colorado. In Denver, a 300,000-strong crowd cheered the nation’s newest astronaut son in their own ticker-tape parade. The city of Boulder declared 29 May as ‘Scott Carpenter Day’, sponsored its biggest-ever celebration and the University of Colorado named the astronaut its most accomplished graduate. Years earlier, Carpenter’s own father, a research chemist, had achieved the same accolade from the same institution. In the case of the younger Carpenter, however, it also came with the formal conferring of his engineering degree, which he completed in 1949, save for a final examination in thermodynamics. The university granted the degree on the grounds that his “subsequent training as an astronaut has more than made up for the deficiency in the subject of heat transfer’’.

Carpenter’s flight brought Project Mercury to another crossroads. In August 1961, the question had been whether to eliminate further Redstone missions in favour of moving towards the Atlas. Now, nine months later, discussion within NASA centred on whether enough had been learned from the three-orbit flights of Friendship 7 and Aurora 7 to justify a still-longer venture. Speaking before the Exchange Club in Hampton, Virginia, NASA engineer Joe Dodson pointed out that the lessons derived from Glenn and Carpenter were pleasing and speculation arose that a day-long mission, to rival that of Gherman Titov in Vostok 2, could be attempted as early as 1963. Indeed, many congressional observers supported a flight to surpass Titov. The debate ended on 27 June, barely five weeks after Carpenter’s re-entry, when NASA Headquarters announced that Wally Schirra would fly Mercury-Atlas 8, possibly as early as September, and attempt up to six circuits of the globe.

Perhaps in reference to the same engineering influence with which Slayton’s Delta 7 had been named, Schirra chose to call his capsule ‘Sigma 7’. ‘‘Sigma, a Greek symbol for the sum of the element of an equation,’’ wrote Schirra in his 1988 autobiography, ‘‘stands for engineering excellence. That was my goal – engineering excellence. I would not settle for less.’’ Nor, indeed, would the ground team, who prepared Sigma 7 for launch with such tenacity and engineering precision. . . and even humorously placed a car key on the capsule’s control stick and stowed a carefully-wrapped steak sandwich in Schirra’s ditty bag. The astronaut sought to honour them, too, during his mission. ‘‘All these little things do really help to make you realise that there are a lot of other people interested in what you’re doing,” he said later. “We know this inherently, but these visible examples of it do mean a lot.’’ The mission would double the number of orbits achieved by Glenn and Carpenter, lasting around nine hours, and as a consequence the Sigma 7 capsule required 20 modifications to provide more consumables. “I think probably the best part of my Mercury mission,’’ Schirra wrote later, “was naming it Sigma 7. Naming it the sum of engineering effort, I wanted to prove that it was a team of people working together to make this vehicle go. That’s why I talk so wildly about knowing the engineers, how they were brothers and buddies… and all of them were! That’s what I saw as the ultimate on that mission, was that [it was] an engineering test flight, where we weren’t going to look around for fireflies. We weren’t going to look for the lights of Perth. We weren’t going to give prayers to the peasants below. We were going to make this thing work like a vehicle!’’

The vehicle which Grissom and Young would fly, and which would demonstrate many of the techniques needed for missions to the Moon, represented a stopgap effort to bridge the gulf between Projects Mercury and Apollo. On 7 December 1961, Bob Gilruth announced in Houston the approval of a $530 million project to use a large Mercury capsule for a series of two-man flights, launched atop the Air Force’s Titan II rocket, to practice rendezvous and spacewalking. It was originally dubbed ‘Mercury Mark II’ or ‘Advanced Mercury’, but the project name ‘Gemini’, with its nod toward ‘the twins’ of classical Greek lore, was suggested by Alex Nagy of NASA Headquarters. Nagy won a bottle of scotch for his trouble and the name was officially announced on 3 January 1962.

Until that time, Project Mercury remained the United States’ only approved manned spacecraft, although plans were afoot to develop it further, and two concepts in particular emerged: one for a temporary orbital station, housing two or more men for several weeks or months, and another for a manoeuvrable vehicle with sufficient aerodynamic ‘lift’ to adjust its flight in the atmosphere. In its 1960 budget request to Congress, NASA asked for $300,000 to study ways of transforming Mercury into a long-duration laboratory, a million dollars to explore methods of making it manoeuvrable and a further three million to investigate rendezvous techniques. ‘‘These modest sums,’’ wrote Barton Hacker and James Grimwood in their 1977 tome ‘On the Shoulders of Titans’, ‘‘signalled no great commitment. When NASA ran into budget problems, this effort was simply shelved and the money diverted to more pressing needs.’’

Still, the Space Task Group was interested in novel ways of controlling the landing of manned capsules and their attention was drawn to a technique devised by NACA engineer Francis Rogallo more than a decade earlier. He had worked on a flexible ‘kite’, with a lifting surface draped from an inflated fabric frame, which had the effect of producing more lift than drag; not as much, admittedly, as a conventional rigid wing, but it had the benefit of being foldable and lightweight. Early in 1959, Rogallo explained his concept to Gilruth, who was sufficiently impressed to implement further study of a follow-on, manoeuvrable Mercury spacecraft which could touch down precisely on land, thereby saving the cost of a naval recovery force. Other suggestions included a two-man Mercury capable of remaining aloft for three days, the addition of a 3 m cylinder at the back of the capsule to support two-week missions or even installing cabling to link the spacecraft to the booster, rotating them and providing experimental artificial gravity.

Unfortunately, with initial steps to develop Project Apollo, plans for advanced Mercury capsules were turned down by NASA Administrator Keith Glennan’s budget analysis team in May I960. Plans at the time amounted to achieving manned suborbital flight before the year’s end and an orbital mission thereafter. These would be followed by an unmanned flight to Venus or Mars by 1962, a controlled robotic landing on the Moon, an unmanned circumlunar mission around 1964 and eventually crewed space stations and circumlunar flights by 1967. Manned landings on the Moon, it was expected, would be a longer-term goal for the Seventies. Of course, this plan would change dramatically with John Kennedy’s speech to Congress in May 1961, but was limited at the time by the weight-lifting capacity of existing rockets and the widely-held assumption that lunar missions would be launched directly from Earth atop very large boosters.

The shift in climate from flying circumlunar missions to actual Moon landings began early in 1961, when George Low, head of manned spaceflight in NASA’s Office of Space Flight Programs, advocated Earth-orbit and lunar-orbit rendezvous techniques at the quarterly meeting of the Space Exploration Program Council. In February, he submitted a report to Bob Seamans, NASA’s newly-appointed associate administrator, stressing that orbital operations and large boosters would be needed, but that developing rendezvous techniques “could allow us to develop a capability for the manned lunar mission in less time than by any other means’’. By the end of that month, NASA Headquarters had taken greater notice and the possibilities of orbital rendezvous assumed centre stage in congressional hearings for the agency’s budget. The House Committee on Science and Astronautics also expressed an interest, scheduling a special hearing on the subject for May and recommending that NASA be awarded the full $8 million it had requested for rendezvous research. The Bureau of the Budget had previously cut this rendezvous spending down to just $2 million, but the committee’s inputs eventually led to NASA getting the funding it needed.

Elsewhere, Jim Chamberlin, an aeronautical engineer working for Toronto-based AVRO Aircraft Inc., joined the Space Task Group and was assigned by Bob Gilruth to oversee the development of an advanced Mercury capsule. Chamberlin seized the opportunity to effectively design a completely new spacecraft, retaining only the proven aerodynamic bell-like shape. In March 1961, at a weekend retreat in Wallops Island, Virginia, he described his plans to Gilruth and NASA’s head of spaceflight programs, Abe Silverstein, sketching out an ambitious machine with its equipment located outside the crew compartment in a self-contained module that would be far easier to install and test. One of Chamberlin’s suggestions was that the advanced

Mercury could be enlisted for circumlunar missions. Although Silverstein dismissed this lunar possibility, he and Gilruth expressed interest in the design itself and on 14 April the Space Task Group and McDonnell signed an amendment to the original Mercury contract, which provided for the procurement of long-lead-time items for six additional capsules. These items would then be used in support of what was now being dubbed ‘Mercury Mark II’.

McDonnell’s early efforts involved making no alterations to the shape of the spacecraft or its thermal protection system, but simply moving retrorockets and recovery equipment into modular subassemblies and, in Chamberlin’s words, creating ‘‘a more reliable, more workable, more practical capsule’’. It would transform, effectively, from an experimental machine into an operational one. By June 1961, when Chamberlin revealed his Mercury Mark II design, some members of the Space Task Group were taken aback: not only did it fulfil the key requirements of extending the spacecraft’s orbital lifetime and making it easier to test, but it essentially involved the repackaging and relocation of virtually every subsystem. This was needed, Chamberlin reasoned, because most of Mercury’s components were inside the cabin, meaning that equipment had to be disturbed in order to reach and fix one malfunctioning device. As it stood, Mercury could do its job, but was far from being a convenient and serviceable spacecraft. Chamberlin’s design allowed for any malfunctioning unit to be removed and tended, without the need to tamper with anything else. ‘‘If one system goes haywire,’’ said Gus Grissom, ‘‘you take it out and plug in a new one.’’

It also tackled the problem of Mercury’s sequencing system, in which many of its operations were automated for safety, by relying for the first time on pilot control; this, too, contributed to a far simpler machine. Chamberlin also advocated the inclusion of an ejection seat and eliminated the need for a Mercury-type escape tower, which he felt contributed hundreds of kilograms of weight to the capsule and argued that its extreme complexity made it inherently dangerous. Moreover, Mercury abort modes were automated, which could terminate a mission in some circumstances where such action may not be necessary. Flying an advanced Mercury with an ejection seat eliminated the option of using the Atlas – the seat could not push the pilots to safety quickly enough in the event that the rocket’s volatile liquid oxygen and RP-1 hydrocarbon mixture exploded. In its stead, Chamberlin suggested the Titan II, which the Martin Company had been developing for the Air Force as an intercontinental ballistic missile.

Martin had already proposed the Titan II as a candidate for lunar missions and, although both Seamans and Silverstein doubted its usefulness, they were sufficiently interested to ask Gilruth to explore ways in which it could be used for other manned projects. Two and a half times more powerful than the Atlas, the Titan seemed, to Chamberlin, perfect for lofting a correspondingly heavier Mercury capsule. The rocket was fed by hydrazine and unsymmetrical dimethyl hydrazine, together with an oxidiser of nitrogen tetroxide. In a catastrophic failure, an ejection seat would be able to outrun the fireball of these less-explosive chemicals. This combination of ‘hypergolics’, capable of spontaneously igniting upon contact, meant that the Titan needed no ignition system and, since they could be held at normal temperatures,

A Gemini-Titan launch. Note the absence of an escape tower; Gemini crews, aboard their conspicuous black-and-white spacecraft, relied instead upon an ejection system. Privately, many astronauts doubted its usefulness.

required no cryogenic storage or special handling facilities. Self-igniting propellants were intrinsically safer and easier to control than the violently-reactive cryogen used by the Atlas.

In any case, Chamberlin reasoned that because the Titan II was two and a half times more powerful than the Atlas, it would be possible to relax the constraints on the spacecraft’s weight. His decision to incorporate an enlarged overhead mechanical hatch in his modified Mercury, primarily as a means of emergency escape, soon expanded to fill another important requirement for lunar missions: the ability to conduct extravehicular activity (EVA), or spacewalking. Meanwhile, efforts to develop Francis Rogallo’s paraglider as a recovery system were gathering pace. The Space Task Group, however, which met with Rogallo and his team in the early months of 1961, felt that too much work had still to be completed before such an experimental device could be committed to a manned spacecraft. Questions were posed over its deployment characteristics, how it was to be packaged and whether the pilot’s view would be good enough to fly and land with it. They advised gathering at least six months’ worth of data before making a decision on whether or not to award actual development contracts. In May 1961, three $100,000 studies were authorised to design an effective paraglider and identify its problems.

Despite the changes to the launch vehicle, the escape system, the hatch, the packaging of components and the recovery operations, Chamberlin’s new spacecraft still resembled the bell-like Mercury capsule and, in its earliest form, was not expected to remain aloft for much longer than a day. Little interest was shown towards developing it further. Then, in July, the Space Task Group began looking at a so-called ‘Hermes Plan’, which envisaged a greatly expanded Mercury Mark II along the lines of that proposed by Chamberlin and, that same month, McDonnell’s Walter Burke outlined three possible forms of an advanced spacecraft. The first simply cut hatches in the side of the capsule to improve access to components, the second – valued at $91.3 million – adhered closely to Chamberlin’s proposal, whilst a third, $103.5 million suggestion envisaged a Mercury carrying not one pilot, but two.

This was not an entirely novel idea, having been brought to the table and quickly rejected in January 1959, but returned to the fore now that the capsule seemed likely to be extensively redesigned. ‘‘If we’re going to go to all this trouble to redesign Mercury,’’ said Max Faget, father of the spacecraft, ‘‘why not make it a multi-place spacecraft in the process?’’ In truth, Faget had already approached McDonnell several months earlier with a similar suggestion. Late in July 1961, Silverstein, Gilruth and several astronauts visited St Louis to view quarter-scale models of four basic spacecraft configurations, together with a full-size, wood-and-plastic mockup of a two-man Mercury, which Wally Schirra clambered inside. His first comment: ‘‘You finally found a place for a left-handed astronaut!’’

Humour aside, the visit proved pivotal, convincing Silverstein that Mercury should be extensively upgraded into a two-man machine. This decision was accompanied by President Kennedy’s commitment to a lunar landing before 1970, which prompted significant changes: the Space Task Group, based at the Langley Research Center in Virginia and originally devoted exclusively to Project Mercury, would be superseded by a Manned Spacecraft Center (MSC), to be situated near

Houston, Texas, as part of a much wider, far more complex and infinitely more expensive effort to land a man on the Moon. Rendezvous provided a means of achieving this goal far sooner than a direct-ascent method and the growing conviction throughout the summer and autumn of 1961 that rendezvous needed to be utilised in some form would provide a framework for what would become Project Gemini.

With the approval of the new project came more emphasis on the Titan II as its launch vehicle. Even though the contract with the Air Force to build the rocket had been signed scarcely a year earlier, Martin’s James Decker proposed that NASA purchase nine Titans for a bargain price of $48 million, the first of which could be ready to fly by early 1963. Among the modifications needed to make it suitable for the Mercury Mark II were lengthened second-stage propellant tanks to increase its payload by 300 kg. Also, the risk of first-stage ‘hardover’ – a malfunction in its guidance system which could drive the gimballed engines to their extreme positions, thereby subjecting the Titan to massive dynamic overloads – could lead to the rocket breaking up before the astronauts could react. A second first-stage guidance system was added to erase this risk.

At the same time, if rendezvous was on the agenda, a rendezvous target was needed and, in August 1961, Chamberlin made his first contact with the Lockheed Missile and Space Company in Sunnyvale, California, with a view to using its highly – successful Agena-B rocket stage. Like the Titan, the Agena ran on storable hypergolics – unsymmetrical dimethyl hydrazine with an oxidiser of inhibiting red fuming nitric acid – and had a ‘dual-burn’ capability; in effect, it could be fired, shut down, then fired again. It also had the potential for the Mercury Mark II, after docking with it, to demonstrate advanced manoeuvres.

The growing importance of rendezvous, docking and manoeuvring was such that the new spacecraft was beginning to change into a new project in its own right and another question that it would be pressed to answer would be the effect of long-term missions on the human body. A journey across the 400,000 km gulf to the Moon and back was expected to require a flight lasting almost two weeks and Mercury Mark II might not only be able to demonstrate that such missions were survivable, but also could evaluate advanced technologies such as electricity-generating fuel cells and more stable attitude-control propellants than hydrogen peroxide. The astronauts, too, would need their own ‘modifications’, in the form of improved space suits to support longer missions.

Ten Mercury Mark II flights, the first in March 1963 and the last in September 1964, would be launched every two months to fly men for up to seven days and animal passengers for as long as two weeks. Investigation of the Van Allen radiation belts around Earth was a second major objective and, indeed, the first flight would be an unmanned test to ensure that the Titan and Mark II were compatible and to boost the capsule to an apogee of 1,400 km. Controlled landings would be the third goal, to be accomplished on each manned mission, most likely with the aid of a paraglider, and rendezvous and docking stood fourth. Later flights would require dual launches of the Titan II and the Agena-B, such that the Mark II could rendezvous and dock. The hope was also there that, if the spacecraft achieved all of its objectives without problems, particularly the long-duration aspect, a Mark II could be launched to dock with a liquid hydrogen-fuelled Centaur stage and boosted onto a circumlunar trajectory. Some short-lived plans even envisaged a manned around-the-Moon mission as early as May 1964. Although they did not get far beyond the drawing boards, one of Chamberlin’s ideas included launching a Mark II atop a Saturn C-3 rocket and placing a manned craft on the lunar surface. Such a landing could, he suggested, be achieved late in 1966.

By the end of October 1961, however, greater emphasis had been placed on developing rendezvous techniques and flying long-duration sorties; Van Allen studies, animal flights and lunar missions were gone. There would be a dozen Mark IIs: an unmanned precursor, followed by an 18-orbit manned mission, a series of extended-duration flights of up to 14 days and, later, rendezvous and docking exercises. Two weeks after NASA formally announced its intention to proceed with Mercury Mark II, on 22 December 1961, James McDonnell signed the contract for its development, agreeing that his company would provide full-scale spacecraft mockups within six months and a mockup of the Agena-B target adaptor by October 1962. By the following March, read the provisions of the contract, McDonnell would supply the first flightworthy spacecraft, with others to follow at 60-day intervals until 12 had been delivered. In effect, this contract replaced the earlier one to procure long-lead-time items for extra Mercury capsules.

It was shortly after the awarding of the main contract that McDonnell began to subcontract out several systems which would prove instrumental in demonstrating the capabilities of the new spacecraft, by now known as ‘Gemini’. One of these was the Orbit Attitude and Manoeuvring System (OAMS), which not only allowed the astronauts to ‘steer’ their spacecraft, but also helped them to station-keep and push away from the second stage of the Titan II. It comprised 16 small engines, fed by hypergolic mixtures of monomethyl hydrazine and nitrogen tetroxide. Each engine was mounted in a fixed position and ran at a fixed thrust level. Eight of them were rated at 11 kg of thrust and provided attitude control. These fired in pairs, permitting the Gemini to roll, pitch and yaw. The remaining eight were ‘translational’ thrusters, each capable of 45 kg of thrust, and were oriented in pairs to fire forward, backward, up/down and left/right. This would form the ‘manoeuvring’ component of the system, although the thrust level of the two forward-firing engines was reduced to 38 kg in July 1962. The re-entry controls, developed by the same subcontractor, North American Aviation’s Rocketdyne Division of Canoga Park, California, consisted of two independent rings of eight 11 kg thrusters located in the nose of the Gemini, forward of the crew cabin. After the main manoeuvring system had effected retrofire, either ring could control the attitude of the spacecraft during re-entry. By the end of May, all major subcontractors had been selected to begin work.

Meanwhile, efforts to secure the Titan II and Agena required Bob Seamans and Assistant Secretary of Defense John Rubel to agree that the Air Force would act in the capacity of a contractor to NASA, whilst at the same time allowing the former ‘‘to acquire useful design, development and operational experience”. The Los Angeles-based Space Systems Division of the Air Force Systems Command would handle the development of the Titan and Agena for Mark II operations and, early in January 1962, NASA issued formal instructions for work on the rockets to begin. Adapting the Titan to handle the spacecraft proved more complex than originally expected, since it required new or modified systems to ensure the astronauts’ safety during the countdown and ascent. By the beginning of March, Lockheed had also started work on the development of a more advanced Agena-D, with an engine capable of being fired more than twice, which would be boosted into orbit atop an Atlas. Unlike the Agena-B, this new version boasted a radar transponder, a forward docking adaptor and an improved attitude-control system. At this time, the first – unmanned – launch of Gemini had slipped from May to August 1963, although the three inaugural flights would be spaced out at just six-week intervals.

Elsewhere, the contract for the paraglider, intended to guide Gemini to a touchdown on land, was awarded to North American on 20 November 1961, but its real future seemed less assured. Chamberlin had defended it vigorously, but Max Faget’s engineering directorate within the newly-established MSC in Houston was cool to the idea, considering its reliability as lower than having main and backup parachutes. Faget instead advocated a steerable parachute, together with landing rockets to cushion the touchdown. Others, including Chris Kraft, felt that neither the paraglider nor the ejection seats were reliable and posed enormous practical obstacles to safety. The paraglider was not aided by North American’s slow progress on its development, which had been unavoidable as Gemini grew from little more than a modified Mercury into an entirely new – and bigger – spacecraft. North American planned free flights of a half-size paraglider for May 1962, although this was delayed because backup parachutes were needed to avoid losing the costly test vehicle. Initial plans called for the first unmanned Gemini to land with ordinary parachutes and the second (manned) flight to utilise the paraglider, although by mid – June it became clear that it would not be available until the third mission. Still, a maiden launch in August 1963 did not seem unreasonable.

However, as 1962 wore on, it was apparent that project costs would be far higher than anticipated. Modification of the Titan II, for example, had climbed from $113 million to $164 million, owing to a multitude of changes to ‘man-rate’ it. These included a fully redundant malfunction-detection system, backup flight controls, an electrical network with backup circuits for guidance, engine shutdown and staging and new launch tracking hardware. Costs of developing the Agena-D similarly increased from $88 million to $106 million and the Gemini spacecraft itself ballooned from $240.5 million to $391.6 million. This cost hike came as a huge surprise, yet it encompassed McDonnell’s enlarged view of what should be included in the project: from ‘realistic’ flight simulators and trainers in Houston and at Cape Canaveral to structural mockups for static and dynamic tests and even the development of an extra spacecraft and docking adaptor for an extended series of unmanned orbital missions (dubbed ‘Project Orbit’) ‘‘to investigate potential problems and to evaluate engineering changes’’. When the Office of Space Flight submitted its Project Gemini review to Administrator Jim Webb in May 1962, the cost of the overall programme had climbed markedly from $529 million to $744 million – and continued to grow.

The half-size emergency parachute experienced difficulties of its own. In a series

of drop tests at the Naval Parachute Facility in El Centro, California, between May and July, four failures led to an extensive redesign and placed it and the paraglider two months behind schedule. Its full-size counterpart also suffered problems and, despite some successes, all three parachutes failed during a November 1962 test and the test vehicle was destroyed when it hit the ground. Although these woes did not directly affect its potential performance, they did introduce worries. Early tests of a half-sized paraglider at Edwards Air Force Base in mid-August had failed to deploy properly after being towed to altitude by helicopter and in two subsequent attempts it was released too soon and landed too hard. A fourth try failed to deploy and a short circuit cancelled a fifth. By the end of September, even Jim Chamberlin was losing patience and ordered North American to halt all tests until it could spell out how it intended to correct the problematic electronics and pyrotechnics. After rework, the half-scale paraglider was shipped back to Edwards and, on 23 October, sailed through a perfect flight, finally demonstrating its stability.

Even the development of the Titan II rocket presented problems. In its first flight on 16 March 1962, it began to experience longitudinal vibrations, occurring 11 times per second for about half a minute. Although these did not pose a problem for the Titan, they would pose a risk for the astronauts, who would be exposed to two and a half times normal gravity and might not be able to react properly to an emergency. The vibrations, nicknamed ‘pogo’, partially disappeared thanks to higher pressure in the rocket’s first-stage fuel tank – perhaps, engineers speculated, it was caused by oscillating pressure in propellant lines – and Martin suggested installing a surge – suppression standpipe in the oxidiser line of later Titan IIs.

Escalating costs and a spending cap limited to $660 million for 1963 eventually led to the realisation that Gemini could only go ahead with the cancellation of the paraglider, Agena and perhaps all rendezvous hardware. Surprisingly, in the subsequent rescoping of the project to take account of budget limitations, the paraglider survived almost untouched and the spacecraft itself retained most of its original features, although the Titan II testing programme was drastically reduced and the decision as to whether the Agena had a role in the project remained fluid for some months. These difficulties conspired to delay the first unmanned mission to December 1963, followed by a piloted flight three months later.

Meanwhile, development of the paraglider continued to be mired with problems. After its October 1962 success, North American refitted the half-scale test vehicle and shipped it back to Edwards for a late November flight. Minor electrical problems postponed the attempt and, when it eventually flew on 10 December, its performance was disappointing: the capsule tumbled from the helicopter, fouled the stabilising drogue parachute and the inflation of the paraglider wing only made matters worse. When the capsule spun down past 1,600 m – the minimum recovery altitude – a radio command detached the wing and allowed it to descend on its emergency parachute. Another try a few weeks later was worse still: it did not tumble this time, but the paraglider storage can was late in separating. The capsule was falling too fast when the wing started to inflate and its membrane tore. Moreover, a faulty squib switch meant the main parachute failed to deploy and the capsule crashed. Despite reporting that five distinct failures had been identified and repaired,

North American’s paraglider was about to breathe its last. Chamberlin gave the project a final chance, but another attempt to deploy a half-scale wing on 11 March

1963 concluded dismally when the storage can failed to separate. The emergency parachute then failed and the paraglider, figuratively and literally, ended its days as a heap of smouldering wreckage.

For the Titan II, the key problem was overcoming its ‘pogo’ oscillations and Martin duly installed a surge-suppression standpipe. However, a test flight on 6 December 1962 actually worsened the pogo effect and, indeed, induced such violent shaking that the first-stage engines shut down too early. Two weeks later, another rocket with no standpipes and increased fuel-tank pressures launched successfully and exhibited lessened pogo levels. A third launch on 10 January 1963 produced similarly encouraging results and the G forces to which it would have exposed a human crew were only slightly higher than those tolerated by Mercury pilots. On the other hand, in this case, the Titan’s second-stage thrust was half of what it should have been, suggesting that its engines had difficulty reaching a steady burn after the shock of ignition. This ‘combustion instability’ proved somewhat more complex than the pogo obstacle and led to a decision in March 1963 to increase the number of unmanned tests and reduce the total of manned flights to ten. To make matters worse, on 8 March, Gemini project cost estimates topped a billion dollars. Days later, Bob Gilruth relieved Chamberlin of his duties and replaced him with Charles Mathews.

Among Mathews’ earliest moves was to insert an unmanned mission in place of one of the manned flights, largely in response to the ongoing Titan II problems. Scheduled for December 1963, the new mission would demonstrate the Titan as Gemini’s launch vehicle. After the upper stage had achieved orbit, a ‘boilerplate’ spacecraft would remain attached and the entire assembly would be left to fall back into the atmosphere. An unmanned suborbital flight with a real spacecraft in July

1964 would then show the ability of the spacecraft to support manned missions. On this plan, the first manned mission, Gemini 3, would come in October 1964. Originally intended as a day-long, 18-orbit mission, Gemini 3 would be reduced by nervous managers to around three orbits – or five hours – and would test the spacecraft’s systems. Earlier plans to fly a Rendezvous Evaluation Pod (REP) on the first manned mission were rescheduled for Gemini IV, which would run for seven days in January 1965. The new schedule implemented three-month gaps between each manned mission, in response to concerns that equipment checkouts and astronaut training required more time. Gemini V would then conduct the first rendezvous and Gemini VI would attempt a 14-day mission, to mimic the length of a full-duration lunar landing expedition. Subsequent flights would last three days apiece, each consolidating and extending rendezvous and spacewalking expertise.

Interestingly, Mathews’ plan did not entirely omit the paraglider, but pushed its maiden flight back to Gemini VII, with parachutes supporting earlier missions. The plan was approved at the end of April 1963. Although paraglider tests in May and June satisfactorily proved its stabilising parachutes, a final drop on 30 July suffered a total failure and crashed. By the year’s end, the paraglider was itself being challenged by the concept of the ‘parasail’, a flexible gliding parachute which offered a quick

and relatively cheap device to achieve a touchdown on land. It could be ready, McDonnell told NASA Headquarters in September 1963, in time for Gemini VII and at a cost of just $15.7 million. It was ruled out, partly due to lack of funds, but chiefly because the paraglider’s vocal supporters objected to giving up on an effort that had already consumed much time and work and was almost ready for flight testing. However, the paraglider itself was on the wane: its landing system programme was stripped of all objectives, save that it would prove the ‘technical feasibility’ of the concept. Parachutes would support most of the Gemini missions, with the paraglider possibly used for the last three. Although Bob Gilruth insisted that it might still fly on Gemini if its tests were successful, the first mutterings of cancellation had reared their heads.

Meanwhile, the Titan Il’s woes continued. A launch on 29 May 1963, carrying pogo-suppression devices for both oxidiser and fuel, burst into flames during liftoff, pitched over and broke up. Although the pogo devices themselves were absolved from blame in the incident, the flight was too brief for their effectiveness to be judged. Three weeks later, a military test of the missile from a silo at Vandenberg Air Force Base in California, although trouble-free during first-stage ascent, with pogo levels within acceptable limits, exhibited faltering second-stage thrust. Had a Gemini crew been aboard, it would have been an abortive mission. The Air Force now shifted its focus to ensuring that the Titan worked as a missile, first, before committing it as a Gemini launch vehicle, and some within NASA even came to doubt that it was the right rocket for the job.

In fact, concerns were so high that the space agency even considered adding yet another unmanned Gemini flight to test the Titan, pushing the total number of missions to 13. Designated ‘Gemini 1A’, it would be slotted in, sometime around April 1964, between the first and second unmanned launches and, like Gemini 1, would consist of a ‘boilerplate’ capsule equipped with instrumentation to examine the performance of the rocket. It would only fly, however, if the unmanned Gemini 1 failed to meet all of its objectives. Although the Gemini 1A hardware was delivered in September 1963, the extra mission had been cancelled by February of the following year, thanks to improved prospects for the Titan II. Despite the fact that two launches in August and September 1963 had gone wrong due to short circuits and guidance malfunctions and the effects of pogo were higher than expected, circumstances improved as the year drew to a close. A Titan launch on 1 November, equipped with standpipes for its oxidiser lines and mechanical accumulators on its fuel lines, reduced pogo effects well below the limit demanded by NASA. Moreover, in the next five months, the rocket would score an impressive and unbroken chain of successes, enough to ‘man-rate’ it in time for Gemini 1.

For all of these problems, the development of the spacecraft itself was going relatively well. Key problem areas remained the fuel cells, propulsion and the ejection seats. McDonnell had already subcontracted to General Electric to build the cells and the first serious development problem of preventing oxygen leakage through its ion-exchange membrane was soon resolved. However, resolution of this problem produced another: test units working over long periods showed degraded performance, apparently due to contamination of the membrane by metal ions from the fibreglass wicks responsible for removing water from the cell. Leakages in the tubes which fed hydrogen to the cells created another obstacle. General Electric replaced the fibreglass wicks with Dacron cloth and an alloy of titanium-palladium replaced the pure titanium tubing, although these developmental headaches pushed the project further behind schedule. NASA was sufficiently concerned to request McDonnell to conduct an evaluation of batteries to be used on Gemini 3, the first manned mission in October 1964, with fuel cells aboard, but only used for flight qualification purposes.

Ongoing problems with the fuel cells, it was realised, could restrict Gemini missions to only a few days under battery power alone. In November 1963, Charles Mathews issued instructions to adapt the electrical system to house batteries or fuel cells and, within weeks, the decision to fly Gemini 3 on batteries was official. Nonetheless, the unmanned Gemini 2 would be equipped with both systems to qualify them. A month later, Mathews decided that Gemini IV – the proposed seven – day mission – should also utilise batteries, which would have a corresponding impact on its duration, shortening it by almost half. Eventually, it would be Gemini V that would first demonstrate the use of fuel cells in space on a week-long flight, with mixed success.

The ejection seats were another concern; so much so, in fact, that the MSC even considered replacing them with an escape tower, akin to that used during Project Mercury. Simulated ‘off-the-pad ejection’, or ‘sope’, tests had been suspended late in 1962 until all components were ready. During one test, the overhead hatch failed to open and the seat shot straight through the 5 cm-thick hull, prompting John Young to remark: ‘‘That’s one hell of a headache… but a short one!’’

Ultimately, the escape system involved a balloon-parachute hybrid, known as a ‘ballute’, which would prevent the astronaut from spinning during freefall if he had to eject from an altitude higher than the 2,000 m at which his personal parachute was supposed to open. The first tests in February 1963 were disappointing: the ballutes failed to inflate and the personal parachute did not deploy correctly, although managers felt that the problem was a dynamic one, caused by the relationship between the rocket motor’s thrust vector and the shifting centre of gravity of the man-seat combination. By May, sope testing resumed and met with greater success and, the following month, dual-seat ejections were demonstrated. Nonetheless, rising costs and unending technical problems, involving the spacecraft, the Titan, the paraglider and even the Agena-D, had conspired to delay the first unmanned Gemini launch until the spring of 1964.

For the paraglider, which experienced yet more failures in December 1963 and February 1964, the end was in sight. Indeed, NASA’s public stance was now that a land touchdown was riskier than an already-proven ocean splashdown, although the Air Force, which was planning its own version of Gemini in conjunction with an orbital laboratory, kept the concept alive for a time. However, the military was not keen to commit funding to the paraglider until it had first been satisfactorily demonstrated by NASA. After yet another test failure on 22 April 1964, William Schneider, Gemini’s project chief at NASA Headquarters, officially announced that no more money would be spent on the paraglider. Ironically, its cancellation was actually followed by several wing-deployment successes. North American even invested its own cash in further development work and, in December, a pilot flew with the helicopter-towed vehicle and guided it to a safe landing. It was, however, too late for it to be reinstated into Gemini.

Of course, the design of the capsule itself had long since been finalised. In fact, the re-entry capsule was comparable in size to the Mercury spacecraft. A broad conical adaptor at its base, which would be shed following retrofire, held the propulsion and long-term power and life-support systems. The capsule, wrote Neal Thompson in his biography of Al Shepard, was “like a snug little sports car”. The white-coloured adaptor was 2.28 m high and 3 m wide at its base and was itself split in two: an equipment section for fuel and propulsion and a retrorocket to support re-entry. Both segments were isolated from each other by means of a fibreglass honeycomb blast shield. The crew cabin, meanwhile, was a truncated, titanium – and-nickel-alloy cone, measuring 2.28 m wide at its base and 98.2 cm at its apex and topped by a short cylinder for re-entry controls and parachutes. In total, the cabin was 3.45 m high and, when mounted on the adaptor, the full Gemini stood 5.73 m tall. Inside, conditions were cramped. The Gemini’s total pressurised volume was little more than 2.25 m3 – “like sitting sideways in a phone booth,’’ John Young said years later – and its outward-opening hatches were positioned directly above each astronaut’s head. Each man was provided with a small, forward-facing window. The spacecraft was equipped with horizon sensors and an inertial reference system and the command pilot flew using a pair of hand – controllers, one for translation, the other for orientation, whilst referring to an ‘artificial horizon’ display.

Key to its manoeuvrability were the 16 OAMS thrusters, spaced around the capsule, and power, at least before the first demonstration of fuel cells, came from three silver-zinc batteries. During preparations for re-entry, the equipment section of the adaptor would be jettisoned, exposing the retrorocket package, whose four motors would initiate the Gemini’s return to Earth. After retrofire, the package would itself be released, leaving the crew cabin, protected by an ablative heatshield and radiative shingles, to withstand the intense heat of re-entry. The centre of mass was deliberately offset to generate aerodynamic lift during re-entry and rolling the capsule using the thrusters on the nose enabled the trajectory to be controlled to aim for a specific geographic position. A parachute-aided descent would finally bring the capsule gently into the Atlantic or Pacific.