Soviet-Russian cosmonaut Valentina Tereshkova, the world’s first woman into space, celebrated her 81st birthday last month. Valentina was launched into space on June 16, 1963, aboard the space capsule Vostok 6, and nearly 55 years after her first (and the only) space mission, Tereshkova still holds the record of being the only woman in the world to have completed a solo space mission.

According to Space.com, Tereshkova was born in 1937 in Maslennikovo village, about 277 kilometers (roughly 172 miles) from Moscow. Her father was a soldier in the Soviet Army. Following the death of her father during the World War II, Tereshkova left her school and started working at a textile factory to support her family. However, she continued her education through correspondence courses and later joined the Yaroslavl Air Sports Club to learn parachute jumping.

Tereshkova was inspired by Yuri Gagarin’s historic space mission in 1961 and decided to apply for the cosmonaut program. On February 16, 1962, she was selected, along with four other experienced parachutists, for the Soviet Union’s first all-female cosmonaut training program.

According to Sputnik News, her intense training included courses on spacecraft engineering, rocketry, parachute jumping, weightlessness, isolation, and more. Although she was not top ranked in the group, her dedication, family background, and overall performance ensured that she was selected for the space mission. Of the five women in her group, only Tereshkova went into space.

Valentina Tereshkova is the first woman to have flown in space, having been selected from more than 400 applicants and five finalists to pilot Vostok 6 on 16 June 1963. #ladiesfirst #girlpower pic.twitter.com/1oxec8eMRZ — Interesting Stuff (@namelesstv) April 5, 2018

The Central Committee of the Communist Party had already approved Soviet rocket scientist Sergei Korolyov’s idea of a dual space mission. The plan was to launch two separate space capsules (one having a female cosmonaut onboard) into space. On June 14, 1963, cosmonaut Valeriy Bykovsky was launched into space aboard the Vostok 5 spacecraft. Two days later, Vostok 6 with Tereshkova onboard, also lifted off. During this space mission, two spacecraft came within 5 km (roughly 3 miles) of each other while being in two different orbits. Tereshkova’s call sign during the mission was “Chaika,” the Russian word for Seagul. Throughout the mission, Yuri Gagarin and Korolyov kept in touch with Tereshkova.

This is the story of Valentina Tereshkova — the first woman in space pic.twitter.com/IJf8UvxmsE — Business Insider (@businessinsider) April 5, 2018

Tereshkova spent 70 hours and 41 minutes in space and orbited the Earth 48 times before successfully landing in Altai, southern Siberia. Tereshkova, for her achievement, received the title Hero of the Soviet Union as well as the honorary title of major-general of aviation. She was also honored with the Order of Lenin.

“Once you’ve been in space, you appreciate how small and fragile the Earth is,” Tereshkova said after her successful space mission.