(CNN) NASA Astronaut Christina Koch is returning to Earth after the longest single spaceflight by a woman.

Koch arrived on the International Space Station on March 14 for her spaceflight mission. She is scheduled to return Thursday after 329 days, breaking Peggy Whitson's record of 288 consecutive days in space.

Koch's is the second-longest single spaceflight by any US astronaut, NASA said in a release.

The hatch on the Soyuz MS-13 spacecraft closed Wednesday night as Koch prepared to return.

At 12:50 a.m. ET, the capsule, which will also carry Koch's fellow International Space Station expedition members, will undock. Around 3:18 a.m. ET, the aircraft will begin its deorbit burn. It is scheduled to land near Dzhezkazgan, Kazakhstan, at 4:12 a.m. ET.

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