The first woman in space has revealed that the Soviet authorities thought it was "too dangerous" to send more female cosmonauts into orbit.
Valentina Tereshkova told BBC News that she protested, writing a letter to the central communist party committee.
It took the authorities 19 years to send another woman into space.
Ms Tereshkova was speaking at the launch of an exhibition about the Soviet space programme at the Science Museum.
She told me: "On Earth, men and women are taking the same risks. Why shouldn't we be taking the same risks in space?"
"We had been preparing for another female flight but it was (the head of the space programme) Sergei Korolev's decision not to risk women's lives because one of the women in the space corps already had a family."
I asked her whether she and the five other trained female cosmonauts disagreed with the decision.
"We were against that decision," she told me firmly. "We wrote to the central party committee disagreeing with the decision."
But history shows it was to no avail. The Soviet Union did not send another woman into space for 19 years, Svetlana Savitskaya, who became the first woman to fly on the Soviet Space station Salyut 7.
There is speculation that she was sent into space because the USSR was aware that the US was preparing to send their first woman into space - Sally Ride.
The revelation is at odds with what the Soviet leader at the time, Nikita Khrushchev, said in a speech at Red Square whilst standing beside Valentina Tereshkova on her return from space.
In it, he mocked the US for its sexual discrimination.
"The bourgeoisie always claim that women are the weaker sex. Now here you can see a typical Soviet woman who in the eyes of the bourgeoisie is weak," he said.
"Look at what she has shown to America's astronauts. She has shown them who is who!"
For Premier Khrushchev, Ms Tereshkova's flight was intended to be a clear signal of equal rights for women under his communist regime.
While in space, Ms Tereshkova spoke directly with Khrushchev, reporting that "all systems are working perfectly" and that she felt "excellent".
He replied: "Valentina, I am very happy and proud that a girl from the Soviet Union is the first woman to fly into space and to operate such cutting-edge equipment".
Ms Tereshkova became the first woman to go into space on 16 June 1963. She completed 48 orbits of the Earth in a trip that lasted almost three days.
Her call signal was "Seagull", and she shouted this joyful message as her Vostok-6 Spacecraft blasted off: "Hey sky, take off your hat, I'm on my way!"
It was at the height of the space race between the US and the Soviet Union. Each country had sent up six astronauts each in an effort to demonstrate national superiority to the rest of the world.
Fifty-two years later, Valentina Tereshkova's capsule is on display at the Science Museum, in an exhibition about the Soviet era of space exploration in the 1960s.
At the opening of the exhibition, she gazed at it lovingly and said she would miss it while it is on display in London - away from the astronaut training facility in Star City near Moscow.
"I reunite with it every day. I never stopped reuniting with this module. Not for a minute, not for an hour, not for a day," she said.
"Every time I meet it, I stroke it and say 'hello my darling' and then go back to work."
In the West, Valentina Tereshkova is one of the forgotten heroes of the space age. At first glorified and portrayed as a symbol of the social enlightenment that communism offered, and then left behind in the great era of Soviet space exploration.
For her own part, she is modest about her own achievement.
"One cannot deny the great role women have played in the world community. My flight was yet another impetus to continue this female contribution," she told me at the Science Museum.
And she issued a message to young women who wanted to follow in her footsteps: "Work hard and you will get there. I am very jealous of you!"
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Cosmonauts: Birth of the Space Age opens to the public at the Science Museum tomorrow