Koch's return comes after an advert for a skincare brand ran during an intermission in the American football Super Bowl with a call to "make space for women".
NASA’s Christina Koch returned to Earth safely on Thursday after shattering the spaceflight record for female astronauts with a stay of almost 11 months aboard the International Space Station.
Koch touched down at 0912 GMT on the Kazakh steppe after 328 days in space, along with Luca Parmitano of the European Space Agency and Alexander Skvortsov of the Russian space agency.
Koch was shown seated and smiling broadly after being extracted from the Soyuz descent module in the Roscosmos space agency’s video footage from the landing site.
“I am so overwhelmed and happy right now,” said Koch, who blasted off on March 14 last year.
Parmitano pumped his fists in the air after being lifted into his chair while Skvortsov was shown eating an apple.
Local Kazakhs on horseback were among those to witness the capsule landing in the snow-covered steppe as support crews gathered around the three astronauts, NASA commentator Rob Navias said.
“I’ve never seen this,” Navias exclaimed, reporting that the men stopped to chat with engineering personnel.
Koch, a 41-year-old Michigan-born engineer, on December 28 last year beat the previous record for a single spaceflight by a woman of 289 days, set by NASA veteran Peggy Whitson in 2016-17.
Koch called three-time flyer Whitson, now 60, “a heroine of mine” and a “mentor” in the space programme after she surpassed the record.
She also spoke of her desire to “inspire the next generation of explorers”.
Koch also made history as one half of the first-ever all-woman spacewalk along with NASA counterpart Jessica Meir — her classmate from NASA training — in October last year.
The spacewalk was initially postponed because the space station did not have two suits of the right size for women, leading to allegations of sexism.
Ahead of the three-and-a-half hour journey back to Earth, Koch told NBC on Tuesday that she would “miss microgravity”.
“It’s really fun to be in a place where you can just bounce around between the ceiling and the floor whenever you want,” she said, smiling as she twisted her body around the ISS.
She will now head to NASA headquarters in Houston, via the Kazakh city of Karaganda and Cologne in Germany, where she will undergo medical testing.
Koch’s medical data will be especially valuable to NASA scientists as the agency draws up plans for a long-duration manned mission to Mars.
Koch’s return comes after an advert for a skincare brand ran during an intermission in the American football Super Bowl with a call to “make space for women”.
The advert featured NASA astronaut Nicole Stott and saw the company promise to donate up to USD 500,000 to the non-profit Women Who Code, which works with young women seeking careers in tech and scientific fields.
The first woman in space was Soviet cosmonaut Valentina Tereshkova whose spaceflight in 1963 is still the only solo mission carried out by a woman.
Russia has sent only one woman to the ISS since expeditions began in 2000 — Yelena Serova whose mission launched in 2014.
Both Tereshkova and Serova are now lawmakers in the Russian parliament, where they represent the ruling United Russia party.
Unlike Koch, whose ISS stay was extended, Parmitano and Skvortsov were rounding off regular half-year missions.
Parmitano handed over command of the ISS to Roscosmos’s Oleg Skripochka on Tuesday.
The 43-year-old Italian posted regular shots of the Earth while aboard, highlighting the plight of the Amazon rainforest and describing the Alps as “like a spinal column, never bending to time”.
Four male cosmonauts have spent a year or longer in space as part of a single mission with Russian Valery Polyakov’s 437 days the overall record.
Scott Kelly holds the record for a NASA astronaut, posting 340 days at the ISS before he returned home in 2016.