Valentina Tereshkova is a familiar name: The first woman in space launched as the pilot of Vostok 6 on June 16, 1963. But she wasn’t the only woman the Soviet Union trained to fly in space. There were five women vying for the spot Tereshkova eventually occupied, and more might have followed in her footsteps had the Vostok program not been phased out.

The impetus to launch a female cosmonaut was political in nature. After beating the Americans with the first satellite and man in orbit, putting a woman in space was just another first the Soviet Union could lord over their Western counterparts. The idea was approved at the end of 1961 by the Central Committee of the Communist Party. Meeting this deadline meant taking in a new class of female cosmonaut candidates.

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The search for qualified women began much in the same way the search for qualified men had years before: deciding what backgrounds and skills were most desired and finding those who fit the bill. Officials looked at women involved with the military, acrobatics, sports involving flying, sky-diving, and even those familiar with parachute jumping (the Soviet Vostok spacecraft has cosmonauts eject and land after returning from orbit). There were also practical considerations, like the size of the spacecraft. Female candidates had to fit inside the cramped cabin. As a reference point Yuri Gagarin, the first man in space, was just five feet two inches. America’s first man in space, Alan Shepard, was a relatively gigantic five feet eleven inches.

Fifty-eight women’s files eventually reached Nikolai Kamanin, the head of the cosmonaut training center, midway through January 1962. He was somewhat unimpressed by the caliber of candidates, but also knew that the high automation inside the Vostok spacecraft would lighten the load on the pilot. Kamanin narrowed the female candidate pool to 23 women, then cut another five after they failed to pass the medical examination.

The remaining 18 women were split into two groups of nine and subjected to extensive interviews and medical examinations. Eleven women made it past this stage, but only five were ultimately selected to being training for spaceflight: Tatyana Kuznetsova, Valentina Ponomareva, Irina Solovyova, Valentina Tereshkova, and Zhanna Yorkina. Kuznetsova dropped out of training, leaving four women fighting for the role of pilot on Vostok 6, a tandem flight with the twin Vostok 5 spacecraft.

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The women received a somewhat frosty reception from their male counterparts upon arrival at the cosmonaut training facility. Many of the men felt women should be anywhere near an airplane let alone a spacecraft. They were unconvinced launching a women into orbit had any intrinsic value, arguing that a potential mother’s life shouldn’t be put at risk. The dangerous work should be left to the men.

But the male cosmonauts slowly started changing their tune when the women got into training. The female candidates demonstrated equivalent aptitude for the job as the men, earning their respect as they went through tests in the centrifuge and altitude chamber. In some cases outperforming the men; Tereshkova emerged from a long-duration isolation test in better spirits than some of her male counterparts had.

There was an unmistakable change in attitude of some men, too, as they started to see the women as attractive women. As relative veterans, the men would offer the women advice during particularly complex or difficult tests. Cosmonaut Andrian Nikolayev, the pilot of Vostok 3, was often seen in the test area while Tereshkova was in training. They eventually married and their daughter, Elena Andrianovna Nikolaeva-Tereshkova, was the first person born to two people who had been in space.

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While the women were training and vying for the prized spot on Vostok 6, the whole Soviet spaceflight program was changing. The Vostok spacecraft was quickly reaching its technical limits, threatening to become obsolete. Chief Designer Sergei Korolev was pushing to launch the new Soyuz spacecraft, the one that would could rendezvous, docking, and eventually make circumlunar flights, but the program was falling behind.

Between December of 1962 and July of 1963, Korolev came up with a plan to extend Vostok’s usefulness. He focused on a handful of research and development missions with dogs and humans. He wanted to push a mission to 11 days in orbit and push the spacecraft’s orbital altitude to nearly 800 miles; these conditions were more indicative of the stresses associated with a science mission or a flight to the moon.

These missions would also serve as a testbed for more daring goals like spacewalks. A dog would be the first living being to leave the safety of a spacecraft in orbit, followed by a man on a later flight. These extended goals demanded changes to the spacecraft, including a better parachute-based landing system and some capacity for cosmonauts to perform EVAs.

In May of 1963, Kamanin gathered the female cosmonauts together and announced that Valentina Tereshkova would be the pilot of Vostok 6. She was well qualified and had the right pedigree; it was the obvious choice. The remaining women, he promised, would fly on later missions. And they might have had a spot in the extended Vostok missions. Though no missions were ever planned, the rough schedule at the time would have had Vostok 7 be a 30-day animal flight, Vostok 8 an 8-day manned mission, and Vostok 9/10 a 10-day tandem flight.

By the time Tereshkova was given her flight assignment these missions were unlikely to ever see the launch pad. Either Korolev or Soviet Premier Nikita Khrushchev (accounts vary) wanted to fast-track a spacecraft that could compete with the American’s Gemini. The extended Vostok missions were cancelled and the spacecraft overhauled into the Voskhod spacecraft, one that could hold multiple cosmonauts and allow one to step out for a spacewalk. The female cosmonaut class did fit into the Voskhod and Soyuz plans. It was 19 years before another woman would fly in space.

Sources: “The First Soviet Cosmonaut Team” by Colin Burgess and Rex Hall; “The Rocket Men” by Rex Hall and David Shayler.