Russian cosmonaut Anton Shkaplerov, followed by Samantha Cristoforetti, of the European Space Agency, and Expedition 43 commander Terry Virts, of NASA, were carried and put on semi-reclined chairs a few minutes later for a breath of fresh air under a setting sun.

A smiling Virts showed a "thumbs-up" sign as a medical worker checked his pulse and blood pressure. "Everything worked by the second, step by step, the guys were great," Shkaplerov said.

The return of the crew from the $100 billion, 15-nation ISS had been delayed for a month after a rocket failed to deliver a Progress cargo craft on April 28. It harmlessly fell into the Pacific Ocean in early May.

Virts said before departing from the ISS that the extra month in space amounted to "bonus days" for the crew. Their mission had been extended to minimise the amount of time the station would be half-staffed.

The crew's departure left Russian cosmonauts Gennady Padalka and Mikhail Kornienko and NASA astronaut Scott Kelly on their own until at least July 23, when cosmonaut Oleg Kononenko, NASA's Kjell Lindgren and Japan's Kimiya Yui are due to launch.