NASA's space champ back on Earth

After clocking up 665 days in orbit American astronaut Peggy Whitson has landed back on Earth after a record-setting flight from the ISS.

NASA space champ Peggy Whitson is back on Earth after a record-setting space flight. (AAP)

NASA's all-time space champ Peggy Whitson is back on Earth after a record-breaking flight.

Whitson and two other astronauts, another American and a Russian, landed in Kazakhstan late on Saturday, US time (Sunday AEST). Their Russian Soyuz capsule undocked from the International Space Station just hours earlier.

Altogether, Whitson has spent 665 days in orbit, more than any other American. Her just-concluded mission lasted 288 days. She became the world's oldest spacewoman and most experienced female spacewalker following her launch last November. She also was the first woman to command the space station twice. This was her third flight.

Returning Russian cosmonaut Fyodor Yurchikhin has logged even more time in orbit: 673 days over five missions. Also back on solid ground is US astronaut Jack Fischer after 136 days aloft. The men flew up in April.