Human beings cannot survive in the vacuum of space, and sustained orbital spaceflight is not yet achievable.
Yuri Gagarin completed a full orbit of Earth on April 12, 1961 - while many of this cohort were still in school. Alan Shepard became the first American in space on May 5, 1961.
What changed?
In the years before Sputnik, human spaceflight wasn’t considered impossible so much as it was considered very far off. Rockets capable of reaching orbit were only beginning to be built. The biological consequences of sustained weightlessness were genuinely unknown, would cardiovascular function collapse without gravity to work against? Would the vestibular system fail? Could a person swallow at all in freefall? The questions were real, the answers absent, and spaceflight remained an engineering challenge without a clear timeline.
The Soviet space programme didn’t wait for all the answers.
On April 12, 1961, Yuri Gagarin climbed into a spherical capsule 2.3 metres across atop a modified R-7 ballistic missile at the Baikonur Cosmodrome in Kazakhstan. One hundred and eight minutes later, after completing a single orbit of Earth at roughly 27,400 kilometres per hour, he parachuted from the capsule at 7,000 metres altitude and landed in a field near the Volga River. He was 27 years old. He had just become the first human being in space.
The Vostok 1 mission answered the basic question, a human being could survive orbital spaceflight, but it immediately raised harder ones. Gagarin had been largely a passenger; the capsule was almost entirely automated, partly because Soviet engineers weren’t certain whether a person in weightlessness could reliably control a spacecraft. Manual controls were aboard, but locked behind a combination seal, the code given to Gagarin in a sealed envelope before launch, and, by some accounts, quietly told to him verbally as well. The mission lasted 108 minutes. The effects of longer stays, bone density loss, muscle atrophy, fluid redistribution, radiation accumulation, would take years of subsequent flights to characterise.
Still, April 12, 1961 was the end of one era and the start of another. The day before, sustained human spaceflight was a distant projection. The day after, it was accomplished fact. When Alan Shepard made the first American spaceflight on May 5, the race was unmistakably underway. President Kennedy announced the goal of a Moon landing before the decade was out just twenty days later. Gagarin’s 108 minutes set in motion a chain of events that ended, eight years afterward, with humans walking on another world.
