After half a year living on the International Space Station, three astronauts safely returned to Earth on Sunday aboard a Russian-built space capsule.

The Soyuz spacecraft landed in the Central Asian steppes of Kazakhstan at 4:14 a.m. ET, returning NASA astronaut Don Pettit, Russian cosmonaut Oleg Kononenko and Dutch astronaut Andre Kuipers to their home planet.

"Everything is good, we feel great," Kononenko radioed Russia's Mission Control Center just before landing.

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The spacefliers undocked from the space station several hours earlier in their Soyuz TMA-03M spacecraft to begin the journey home. They landed upright under a blue sky dotted with some white clouds in Kazakhstan, where the local time was Sunday afternoon. Live video tracked the Soyuz's descent at the end of its parachute, right down to the ground.

Veterans return from frontier
Pettit, Kononenko and Kuipers arrived at the orbiting outpost in December 2011. All three had flown previous missions to the space station, making them a crew of veteran spacefliers.

In a blog post describing his final day in space, Pettit reflected on the impact of his months-long mission, and encouraged humanity to keep pushing the boundaries of space exploration.

"On Earth, the frontiers opened slowly," Pettit wrote. "The technology of sailing was known and advanced for over a thousand years before the Earth was circumnavigated. Such bold acts require the technology, the will, and the audacity to explore. Sometimes you have one, but not the others. I only hope that my small efforts here, perhaps adding one grain of sand to the beach of knowledge, will help enable a generation of people in the future to call space 'home.'" [Landing Photos: Soyuz Capsule Returns 3 Astronauts Home]

Throughout their mission, Pettit and Kuipers shared stunning photos of Earth from space with the public through Twitter and the Flickr photo-sharing site. Pettit also regularly updated his blog with accounts of his experiences on the space station, including several poems in tribute to life in space.

Pettit kept a journal as a fun way to document his scientific activities on the orbiting outpost. For instance, Pettit wrote blog updates using the persona of a zucchini plant when he experimented with growing different kinds of plants in microgravity.

On Friday, Pettit wrote a poem called "Last Day in Space," touching upon his memories of the mission, the experiences that moved him, and his anticipation over seeing his wife and children again soon.

Milestone mission
Pettit, Kononenko and Kuipers made up half of the station's Expedition 31 crew. During their stay at the orbiting laboratory, the spacefliers rolled out the welcome mat for the first commercial spacecraft to visit the station.

SpaceX's unmanned Dragon capsule was launched to the International Space Station on a test flight to demonstrate the spacecraft's ability to carry cargo to and from low-Earth orbit. As Dragon approached the station, Pettit and Kuipers used the outpost's robotic arm to pluck it from space and manually park it to the complex.

Sergey Remezov  /  AFP - Getty Images

The Soyuz TMA-03M capsule lands near the town of Dzhezkazgan on July 1, 2012.

The successful test flight lays the groundwork for NASA to use commercial spaceships to ferry cargo — and one day, astronauts — to the space station. SpaceX holds a $1.6 billion contract with the agency for 12 unmanned cargo delivery flights.

Kononenko served as commander of Expedition 31 during his stay, but passed the torch to fellow Russian cosmonaut Gennady Padalka during a change-of-command ceremony Saturday.

The departure of Pettit, Kononenko and Kuipers leaves only three residents occupying the space station until three new crewmembers launch to the complex on July 14. Padalka, NASA astronaut Joe Acaba and Russian cosmonaut Sergei Revin will remain aboard the orbiting outpost until September.

Russian space station flight controllers radioed Padalka and his Expedition 32 crew after Sunday's landing to let the spacefliers know their comrades were back on Earth and in good health.

"Good to hear," Padalka radioed back. "Another mission completed."

This report was supplemented by msnbc.com. Follow Denise Chow on Twitter  @denisechow, or Space.com  @Spacedotcom. We're also on  Facebook and  Google+.

• Photos: Space Station's Expedition 31 Mission
• Stunning Photos: Earth from Space by Astronaut André Kuipers
• Photos: Exquisite Star Trails Captured by Astronaut Don Pettit