“Tired of Apologising”: The Flight of Aurora 7

Five weeks before launch, Scott Carpenter and his backup, Wally Schirra (back to camera), undertake emergency water egress training for the mission. By his own admission, Schirra was furious to have been skipped for Carpenter, having trained for several months as Deke Slayton's backup. Photo Credit: NASA

Fifty years ago, this week, America launched its second man into orbit. That man should have been Deke Slayton, but a heart murmur had grounded him, not in favour of his backup, Wally Schirra, but in favour of John Glenn’s backup, Scott Carpenter. The theory was that the second orbital voyage would essentially repeat Glenn’s achievement (five hours and three orbits) and it made sense to fly Carpenter and keep Schirra for a subsequent mission. Schirra learned of the change in assignment during an impromptu gathering at the Carpenters’ home…and what should have been the most exhilarating moment of Scott Carpenter’s life turned instead into an ordeal. Slayton was angry at having lost his mission and Schirra was indignant at having been skipped in the pecking order, to such an extent that Carpenter felt he was spending more time apologising than training. One evening, Carpenter told his wife, Rene: “Damn it! I’m tired of apologising. This is my flight now!” The flight would prove highly successful in many ways, highly controversial in others, and, it is said, would deny Carpenter the chance of ever flying into space again.

Wally Schirra felt no bitterness towards Carpenter, but in his autobiography, Schirra’s Space, he acknowledged that “the system was rotten”. In Schirra’s mind, Carpenter had been through test pilot school, but was a multi-engine aviator and communications officer…not a fighter pilot. Yet Carpenter had many impressive credentials. In a December 1960 ‘peer vote’ for who they felt should be the first American man in space, John Glenn placed Carpenter at the top of his list. During the selection process for Project Mercury, Carpenter once blew into a tube of mercury for three minutes – far longer than anyone else – and showed himself capable of enduring the centrifuge at 18 G, using explosive ‘grunting’ to breathe.

When he was named as pilot of the seventh Mercury-Atlas mission (MA-7) in March 1962, Carpenter decided to call his craft ‘Aurora 7’. “I think of Project Mercury and the open manner in which we are conducting it for the benefit of all as a light in the sky,” he wrote later. “Aurora also means ‘dawn’ – and, in this case, the dawn of a new age. The Seven, of course, stands for the original seven astronauts.” By now, the suffix had become commonplace and, coincidentally, ‘Aurora’ also happened to be the name of one of two streets bordering Carpenter’s boyhood home in Boulder, Colorado.

A few days after his mission, Scott Carpenter was honoured as Boulder's newest hero, with a triumphant parade through the city. Photo Credit: NASA

Owing to the ‘experimental’ nature of Friendship 7 – “for all its first-time danger,” wrote Carpenter and his daughter Kris Stoever in For Spacious Skies, “MA-6 had been designed to answer the simple question: Could it be done?” – the next mission would encompass more engineering tasks and scientific activities, including observations, photography and extensive manoeuvring. Deke Slayton, when the flight was still his to fly, had expressed consternation at the sheer volume of tests and experiments. “Everybody and his brother came out of the woodwork,” he wrote. “One guy wanted me to release a balloon to measure air drag. Another guy had some ground observations I was supposed to make. I had my hands full trying to resist it.” From 16 March 1962, Carpenter found that the scientific demands of were his to handle: they included combined yaw-roll manoeuvres to study orbital sunrises, use of terrestrial landmarks and stars for navigational reference and flying in an inverted, head-towards-Earth attitude to determine the effect of ‘Earth-up/sky-down’ orientation on the pilot’s abilities.

Delayed from 19 May 1962, the launch was rescheduled for the 24th. Carpenter was awakened at 1:15 am EST and proceeded through the usual pre-flight rituals: breakfast, a medical examination and suiting-up. He was aboard Aurora 7 by 5:00 am, to enjoy one of the smoothest countdowns yet experienced 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. In fact, his wife Rene and their four children represented the first astronaut family to journey to Cape Canaveral to watch the launch in person. To avoid media attention, a neighbour had provided a private flight to Florida and a non-descript car, which Rene drove to the astronauts’ hideaway 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 out onto the beach to watch their father’s launch. Elsewhere, an estimated 40 million viewers watched as America launched its second man into orbit. Carpenter 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 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.

Amidst smoke and flame and an unearthly roar, the Atlas rocket blasts Scott Carpenter into orbit on 24 May 1962. Photo Credit: NASA

Already, however, the first glitches of what would become a troubled mission were rearing their heads. Aurora 7’s pitch horizon scanner – meant to monitor 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 a perceived error; thereby wasting precious fuel. Forty seconds after the separation of the escape tower, the scanner was 18 degrees in error. It had reached 20 degrees in error by the time Carpenter achieved orbit. As the flight wore on, the error persisted and produced “near-calamitous effects”.

For now, the euphoria of being in space overtook the astronaut. “I am weightless!” he cried. Deciding not to rely on the automatic controls, Carpenter’s use of fly-by-wire smartly turned the capsule around at a fuel expense of just 725 grams, as compared to 2.3 kg on Friendship 7. No sensation of speed was apparent, although he was now travelling at 28,240 km/h and soon received his first “arresting” view of Earth.

Five and a half minutes into the mission, Carpenter received notification that his orbit was good enough for up to seven orbits. He quickly got to work. “With the completion of the turnaround manoeuvre,” he wrote later, “I pitched the capsule nose down, 34 degrees, to retro attitude, and reported what to me was an astounding sight. 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 out his flight plan index cards and Velcroed them into place; these would provide him with timing cues for communication 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 flight.

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 experienced with his gyro reference system, and cognisant of the fact that he had much other work to do, Carpenter dismissed it.

The stunning grandeur of a cloud-bedecked Earth, viewed by Scott Carpenter and his hand-held camera. Photo Credit: NASA

“A thorough [automatic stabilisation and control system] check, early in the flight, could have identified the [horizon pitch 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 capsule’s autopilot.

Passing over the ground station at Kano, in north-central Nigeria, Carpenter successfully photographed the Sun for MIT physicists, then, over the Indian Ocean, acquired initial readings for a study of atmospheric ‘airglow’. However, conditions aboard the spacecraft were becoming uncomfortable, as cabin temperatures increased. Years later, in The Right Stuff, Tom Wolfe described Aurora 7 as “a picnic” and noted that its astronaut had “a grand time”; Carpenter, however, countered that his shorter-than-normal preparation for his 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’ 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 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 attitude was 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 later. “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 clock. Carpenter noticed that his space suit temperature was higher than normal, but there was little time to ponder it further, as he passed over Australia’s Great Victoria Desert and prepared to observe four flares of a combined one million candlepower. Unfortunately, the cloud cover was too dense and he saw nothing.

Scott Carpenter's Earth observations were aided significantly by the presence of a large trapezoid window, clearly visible in this pre-launch image as the astronaut inspects his spacecraft. Photo Credit: NASA

Another aspect of the mission about which no joy was forthcoming was a multi-coloured balloon, which he released 100 minutes after launch. For a few seconds, the expected ‘confetti spray’ signalled a successful deployment, but is soon became clear that the balloon had not inflated properly: due to a ruptured seam in its skin, it deployed to about a third of its expected diameter and only two of its five colours – Day-Glo orange and dull aluminium – were visible. Two small, ear-like appendages, described as “sausages”, emerged on the edges of the partially-inflated sphere. Its movement was erratic and, although Carpenter succeeded in acquiring a few measurements, the tether quickly wrapped itself around Aurora 7’s nose. Consequently, the aerodynamic data was of limited use. Carpenter attempted to release the balloon, 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-percent capacity for 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 percent. He felt he had expended additional fuel trying to orient the spacecraft 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 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,” he wrote later, “meant the pilot had no way of disabling, or locking-out, these high-power thrusters.” Subsequent Mercury flights had an on-off switch for just that purpose.

The still-unknown glitch with the horizon pitch scanner remained. Two hours into the mission, Carpenter was informed that he should now be transitioning Aurora 7 from automatic to fly-by-wire control. The astronaut opposed this, preferring to remain in automatic mode, which was supposedly more thrifty with fuel consumption. Unfortunately, this was not the case, because the malfunctioning pitch horizon scanner was feeding incorrect information into the autopilot, which, in turn, was guzzling more fuel than it should. A few minutes later, Carpenter reported difficulties with the automatic control mode and switched to fly-by-wire in an effort to diagnose the problem.

Carpenter trains in the Air Lubricated Free Attitude (ALFA) simulator at Langley Air Force Base, Virginia. Photo Credit: NASA

Although a malfunctioning automated navigation system was tolerable, it was essential for retrofire to ensure that the spacecraft was properly aligned, along the pitch and yaw axes, to commence 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. Carpenter 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, then watching the terrain pass beneath him or use a certain geographical feature or cloud pattern for reference. However, this was nearly impossible over featureless terrain or stretches of ocean.

Carpenter had other worries, too. His cabin and pressure suit temperatures were climbing to uncomfortable levels; the former, in fact, peaked at 42 degrees Celsius and the latter rose to 23.3 degrees Celsius and a “miserable” 71 degrees of humidity. A query from the ground as to whether the astronaut felt comfortable 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 air-flow rates and good circulation, as well 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 pills for post-flight urinalysis and monitor his scientific experiments. He also managed to eat solid food during the mission: the Pillsbury Company had prepared chocolate, figs and dates with high-protein cereals, whilst Nestlé provided bonbons, composed of orange peel with almonds, high-protein cereals with almonds and cereals with raisins. These was 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.

Despite the fuel usage problems, Flight Director Chris Kraft commented in his post-flight report that, so far, Aurora 7 had run smoothly. He felt that sufficient fuel remained to achieve the proper retrofire attitude, hold it and successfully re-enter the atmosphere with either the automatic or manual controls. It was from this period onwards that the mission’s fortunes would change markedly and so too, it is said, would many attitudes towards the performance of Scott Carpenter himself.

The final part of this article will appear on Tuesday.

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