By Irene Klotz

CAPE CANAVERAL, Fla (Reuters) - NASA astronaut Peggy Whitson left the International Space Station on Saturday, wrapping up a career-total 665 days in orbit, a U.S. record, as she and two crewmates headed for a parachute landing in Kazakhstan.

Whitson, 57, ends an extended stay of more than nine months aboard the station, a $100 billion research laboratory that flies about 250 miles (400 km) above Earth.

"I feel great,” the biochemist said during an inflight interview on Monday. “I love working up here. It’s one of the most gratifying jobs I’ve ever had.”

During her third mission aboard the station Whitson spent much of her time on experiments, including studies of cancerous lung tissue and bone cells. She also completed four spacewalks, adding to her six previous outings, to set a record for the most time spent spacewalking by a woman.

Two crewmates who launched with Whitson in November returned to Earth three months ago. She stayed aboard to fill a vacancy after Russia scaled down its station staff from three to two cosmonauts.

Whitson returns to Earth with Jack Fischer, also with the National Aeronautics and Space Administration, and Russian cosmonaut Fyodor Yurchikhin, who arrived in June. The crew’s Russian Soyuz capsule was expected to make a parachute touchdown in Kazakhstan at 9:22 p.m. EDT Saturday (0122 GMT Sunday).

"I’m looking forward to seeing friends and family,” Whitson said during another interview. “But the thing I’ve been thinking about the most, kind of been fantasizing about a little bit, are foods that I want to make, vegetables that I want to sauté, things that I’ve missed up here.”

In April, Whitson broke the 534-day U.S. record for cumulative time in space. Only seven Russian men have logged more time, including Gennady Padalka, the world record-holder with 878 days in orbit.

Whitson, who grew up on a farm in Iowa, said she was inspired by the U.S. Apollo program that landed men on the moon and she was selected as an astronaut in 1996. She was the first woman to command the space station and also the first woman and first non-pilot to serve as chief of the NASA Astronaut Corps.

“I am working on paying forward some of the advice and mentoring that I received on my journey, in hopes that one day those young people will do the same and look back on a life in which they leapt at the opportunities and broke their own records," she said.

(Reporting by Irene Klotz; Editing by Bill Trott)