Whitson, who grew up on a farm in Iowa, said she was inspired by the US Apollo program that landed men on the moon, but it was not until later, when the first women become astronauts, that she set her sights on joining them.
Along with another American and a Russian, she landed in Kazakhstan shortly after sunrise on Sunday.
It marked the end for the Expedition 52 crew, which had manned the space station together since April.
During her third mission on ISS - extended to nine months after Russian Federation scaled back its deployments - Whitson conducted experiments, including studies of cancerous lung tissue and bone cells.
She said her home in Houston is fine, but many friends and co-workers were not as fortunate.
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More than 400 Hindus from Rakhine have also crossed into Bangladesh, after armed men attacked their village, killing and looting. In 2009, a United Nations spokeswoman even described the Rohingya as "probably the most friendless people in the world".
Back at the space station, NASA astronaut Randy Bresnik, European Space Agency astronaut Paolo Nespoli and Russian cosmonaut Sergey Ryazansky will be the only three crewmembers on board until September 12, when the Expedition 52/53 crewmembers arrive.
Whitson broke the USA record of 534 cumulative days in orbit during the mission. "We will do our utmost to show the same dedication and fortitude every single day that you guys exemplified every single day".
Watch Whitson, Yurchikhin and Fischer's return in real time via NASA's live feed below.
Russia's Soyuz MS-04 spacecraft with three crew members on board is performing a retrograde burn to ensure proper velocity and positioning for a safe landing, a Russian Mission Control center official told TASS on Sunday.
During the change-of-command ceremony, Bresnik took over from Yurchikhin, who presented him with a symbolic "key to the space station".
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More than 800,000 people, often called Dreamers, have participated in the program as of earlier this year, according to U.S. Those benefits came five years ago, when the Obama administration began the DACA program.
"I honestly do think that it is critical that we are continuously breaking records, because that represents us moving forward in exploration", she said. "I love being up here".
During an in-flight interview last Monday, the biochemist said: "I feel great. Having three more months to squeeze is just what I would wish for".
Yurchikhin has spent 673 days in space during five missions, while Fisher has spent 136 days. They had the station to themselves until July 28 when Ryazanskiy, Bresnik and Nespoli arrived.
For the next year or so, the station's six-member crew will feature two cosmonauts and four USOS crew members.
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Watt said he's been moved by watching everyone that has helped out in the crisis so far and is looking forward to pitching in. The team has been practicing at the Cowboys' facility in Frisco, Texas, this week.