Chimps, ‘Pee-Sacks’ and Timid Germans: The Fateful Decisions of Freedom 7

Fifteen minutes after leaving Cape Canaveral, Alan Shepard splashed down in the Atlantic Ocean and is pictured being winched to safety. His mission paled in comparison to Yuri Gagarin's orbital flight, but helped to light the touchpaper for America's drive to land a man on the Moon. Photo Credit: NASA

When Alan Shepard came home on 19 January 1961, he brought exciting news. Earlier that day, he had been privately notified that he would fly the United States’ first manned space mission, a 15-minute suborbital ‘hop’ aboard a Mercury capsule. Shepard would launch from Cape Canaveral in Florida in early March, atop a converted Redstone missile, rise to a maximum altitude of 180 km and splash down in the Atlantic. By this time, the competition between the United States and the Soviet Union had reached its most intense point…and the Russians were clearly in pole position: they had launched the world’s first artificial satellite, the first robotic probe to the Moon and they intended to put a man into space. When Shepard told his wife, Louise, that she had her arms around the first man to conquer the new frontier, her reply was a little sarcastic: “Who let a Russian in here?”

Those words were sadly prophetic, for in April 1961 it was indeed a Soviet cosmonaut, Yuri Gagarin, who first entered space and Shepard missed out on making history by just three weeks. Privately and publicly, he would fume at the lost opportunity, but getting a man into space had always been a close-run race to the finish. Moreover, Gagarin’s flight was an orbital one, whereas that of Shepard was suborbital – a “flea-hop,” as Soviet Premier Nikita Khrushchev scornfully called it – and it would be some months before the United States had the capability to place a man into orbit. Still, had Shepard flown as planned on 6 March 1961, he would have beaten Gagarin into space and some observers have attributed America’s failure to two unlikely characters: an unhappy chimp and a timid German.

Shepard’s tiny Mercury capsule – a cone-shaped craft, barely large enough for a single person to squeeze inside – rolled out from prime contractor McDonnell Aircraft Corporation’s plant in Missouri in December 1960. It was dubbed, rather blandly, ‘Spacecraft No. 7’, and should have been capable of taking him into space almost immediately, although several months of testing, repairs and rework were needed before it could be entrusted with its first human pilot. In the meantime, a chimp would fly a Mercury craft in January 1961, to demonstrate its capabilities with a live passenger, and this harrowing episode would plant the first seeds of doubt in many minds and hammer a nail into the coffin for America’s chances of beating the Russians into space.

The chimp’s name was ‘Ham’. It came from the acronym for the Holloman Aerospace Medical Center, based at Holloman Air Force Base in New Mexico, which prepared him for his mission. Chimps were favoured because of their close approximation to human behaviour and a six-strong colony – four females and two males – arrived at Cape Canaveral in early January 1961. They trained with Mercury mockups in their compound and quickly learned to pull levers and push buttons in the right order, receiving banana pellets or mild electric shocks for doing the right or wrong thing. Twenty-four hours before launch, the six chimps were examined and the frisky and good-humoured Ham was selected as the prime candidate. His flight would clear the way for Shepard’s own mission, five weeks later.


The chimpanzee Ham, pictured before his flight. Named in honour of the Holloman Aerospace Medical Center, where he was trained, the chimp proved that the Mercury spacecraft was habitable for a human pilot. Photo Credit: NASA


Ham’s home for the 16-minute suborbital voyage was a fully-functional Mercury craft, with active environmental controls, live retrorockets, a voice communications device and a specially fabricated landing bag to cushion the water impact and keep the capsule upright in the Atlantic. The chimp’s liftoff was successful, although a fault in the Redstone meant that the capsule overshot its intended altitude and distance; it flew 67 km higher than it should have done and 200 km further downrange. This affected the re-entry positioning and poor Ham experienced six and a half minutes of weightlessness, followed by a peak of 14.7 times the force of normal terrestrial gravity as he plunged back to Earth. He survived, but the capsule’s heat shield skipped on the water, bounced against the base of the craft and punched two holes in its pressure bulkhead. Seawater flooded into the cabin and the “very unhappy” chimp was eventually recovered by the USS Donner.

Post-flight investigation revealed that a faulty fuel valve in the Redstone caused an early depletion of liquid oxygen, triggering an increased propellant consumption rate, a higher thrust and an earlier-than-planned engine shutdown and separation of the capsule. Nonetheless, conservative estimates judged the probability of success with a trained human pilot at 78-84 percent – and Shepard himself thought the odds were much better – and there was confidence that Ham’s problems could be overcome. However, for Wernher von Braun, the German rocket engineer who had spearheaded the development of the Redstone for the US Army, it was not enough.

As the first director of NASA’s Marshall Space Flight Center in Alabama, von Braun was well aware of the rules: no manned flight could take place until all responsible parties felt assured that everything was ready. He refused to give his consent for a piloted flight until another unmanned test of the booster had been completed. Von Braun stood firm and NASA’s senior leadership stood with him. The astronauts and their managers were furious; Chris Kraft, then a flight director, was livid that this “timid German” had fouled their plans from the inside. The delay inevitably postponed the manned mission until at least 25 April; in the meantime, the unmanned Booster Demonstration in late March was perfect and both the Redstone and the Mercury capsule performed admirably.

At the time of Alan Shepard's launch on 5 May 1961, the reliability of American spacegoing rocketry was - in Chris Kraft's opinion - no higher than 60 percent. The bravery and steely nerve of the men who rode these early rockets should never be forgotten. Photo Credit: NASA

Adding fuel to the fire was Jerome Wiesner, recently picked by President John F. Kennedy as his science advisor, who warned that a dead astronaut could have a profound impact on the new administration’s fortunes. Wiesner assembled a panel of experts to assess the situation and make a recommendation. His panel, the President’s Science Advisory Committee (PSAC, disparagingly dubbed ‘pee-sack’ by the astronauts), eventually concluded that the manned mission should fly. Their report landed on President Kennedy’s desk on the afternoon of 12 April 1961…by which time Gagarin had already landed from his historic orbital voyage. Not surprisingly, Wiesner’s panel and von Braun were the targets of much criticism as the United States fell again into second place in the space race.

Yet it is important to consider that space exploration at this time was very much in its infancy. “The reliability of a rocket-propelled system in 1961 was not much better than 60 percent,” Chris Kraft recalled in his NASA oral history, “and you may begin to have a feel for the anxiety all of us were experiencing.” Preparations for the manned flight continued. Shepard and his backup, John Glenn, had averaged 60 hours per week in the Mercury mockup since February, reviewed flight plans and endured dozens of simulated Redstone launches. By March, their training had expanded to include the full ritual of medical examinations and the donning of their space suits. The sense of readiness as March slipped into April was pervasive. At length, a date in early May was selected as the start of America’s human adventure in space and on the 5th Alan Shepard, in the capsule he had named ‘Freedom 7’, made history for his nation.

Many of the events preceding Shepard’s mission were ill-fated – the problems with Ham’s rocket, the concerns of Wernher von Braun and Gagarin’s launch – but ‘fate’ does not necessarily imply misfortune. Two weeks before Shepard flew, President Kennedy secretly authorised the CIA to support 1,500 Cuban exiles, with the intention that they would lead a counter-revolutionary effort to topple Fidel Castro. The abject failure of the ‘Bay of Pigs’ invasion, and the embarrassment that it caused Kennedy, coupled with the shock of Gagarin’s mission, prompted the new president to do something – anything – to restore a measure of credibility to his administration, which was still only four months old.


Despite a decade of frustration after his Freedom 7 flight, Alan Shepard became the only Mercury astronaut to walk on the Moon. If his Freedom 7 flight inspired America to pursue the lunar goal, then his Apollo 14 flight saw that pursuit through to completion. Photo Credit: NASA


On 25 May, that ‘something’ was anounced before a joint session of Congress: a presidential directive to land a man on the Moon, before the end of the decade. Much has been written over the years about Kennedy’s motivation for nailing his colours to the space mast, and it is not difficult to see an ostensibly ‘scientific’ goal on a cynical foundation of political point-scoring and a need to demonstrate American technological might. The extent to which Kennedy really ‘loved’ space exploration is still questioned, with some historians arguing that he wanted to cancel Project Apollo outright, just months before his death, due to its spiralling cost, and others adding that he used the space programme as nothing more than a pawn to surpass the Soviets. Still, the fact remains that without the ‘fateful’ events which preceded Alan Shepard’s mission, it is unlikely that an American astronaut would have been ‘fated’ to plant his bootprints into the dust of the Sea of Tranquillity in July 1969.

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    • Many thanks for your comment, Mr Oberg. It is intriguing to speculate which direction Kennedy might have taken if Shepard had made it into space (though not orbit) ahead of Gagarin. What are your thoughts? Would he have still gone for a man on the Moon?

      Kind regards,


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