• The crew launched Sept. 21, 2022 for what was to be a six-month mission before a coolant leak in their return craft lengthened their stay aboard the space station.
• Rubio and his Russian companions landed Wednesday morning in a remote area of Kazakhstan after having spent 371 in space.
• Before Rubio's mission, NASA astronaut Mark Vande Hei was the American who had spent the most consecutive days in space, having returned to Earth in 2022 after 355.

NASA astronaut Frank Rubio didn't set out to break any spaceflight records when he and two Russian cosmonauts launched aboard a rocket more than a year ago bound for the International Space Station.

The mission was only meant to last six months. But that was before a piece of space junk pierced the explorers' original capsule late last year, requiring a new Soyuz spacecraft to be rushed up to them for their return journey to Earth.

Ultimately, Rubio would spend 371 days in space before his mission came to an end, according to NASA. Rubio and his Russian companions — Sergey Prokopyev and Dmitri Petelin — landed Wednesday morning in a remote area of Kazakhstan in the replacement Soyuz capsule that had only reached them aboard the space station two weeks ago.

It might not have been Rubio's intention, but his lengthy and unanticipated stay in space helped him make history: The 47-year-old astronaut now holds the American record for the longest spaceflight, surpassing the previous endurance record set in 2022 by more than two weeks.

“It’s good to be home,” Rubio said after being pulled from the capsule, according to the Associated Press.

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Expedition to space station intended to last six months

When Rubio and the two cosmonauts launched Sept. 21, 2022 from the Baikonur Cosmodrome in Kazakhstan, they thought they'd return to Earth the following March aboard the same spacecraft.

But that was not to be.

A coolant leak in the Russian MS-22 Soyuz was detected in December while it was docked at the space station, meaning the trio would require a new ride home. NASA and Russian space agency Roscosmos later determined that a micrometeoroid had damaged the craft's radiator, causing coolant to spew into space for hours.

Engineers worried that without cooling, the capsule’s electronics and any occupants could overheat to dangerous levels. Instead, the craft returned home empty while NASA and Roscosmos in February sent up a replacement spacecraft to the stranded crew, delaying the arrival of a new team of astronauts to relieve them.

Since launching from Kazakhstan last September, Rubio and his crew logged more than 157 million miles and orbited Earth 5,963 times, NASA said. After undocking from the space station in the Soyuz craft at 3:54 a.m. Eastern Time this morning, the trio landed on schedule at 7.17 a.m. on the steppe of Kazakhstan, southeast of the town of Dzhezkazgan, according to the space agency.

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Who held the previous American spaceflight record?

Rubio's stay in space was 16 days longer than Mark Vande Hei's time aboard the International Space Station.

Vande Hei returned to Earth in March 2022 after 355 days in space, which was at the time the record for the longest continuous spaceflight by an American.

However, it's Russian cosmonaut Valeri Polyakov whose 437 consecutive days spent in space in the mid-1990s remains the world record. Polyakov's milestone mission occurred between 1994 and 1995 aboard the Russian space station Mir, according to Astronomy.com.

Who is Frank Rubio?

An Army doctor and helicopter pilot, Rubio joined NASA in 2017.

Before joining the space program, Rubio served in the U.S. Army flying combat missions in a Blackhawk helicopter during deployments to Bosnia, Afghanistan, and Iraq. In 2010, Rubio earned a doctorate in medicine and remains a board-certified family physician and flight surgeon.

A native of Los Angeles, Rubio resides in Miami, Florida with his family.

Rubio's year-long expedition to the International Space Station was his first mission to space.

Making the most out of his time aboard the space station, Rubio worked on numerous science projects, including studying how bacteria adapt to spaceflight and how future astonauts can exercise and best maintain physical health. He also conducted three spacewalks surpassing 21 hours.

The investigations may prove invaluable for future missions, but in a September interview with Vande Hei shared by NASA, Rubio said that his proudest moment was to have the opportunity to fly with 28 different people aboard the space station.

"Every one of them have just been great crewmates, very special people and they hold special places now because I've been able to share this experience with them," Rubio said. "That's the memory that I'll hold most dear forever."

Now that he's landed, Rubio and his Russian companions Prokopyev and Petelin were to be flown from the landing site to Karaganda, Kazakhstan. From there, the American astronaut was to board a NASA plane back to Houston — a trip that this time won't be delayed.

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Contributing: The Associated Press

Eric Lagatta covers breaking and trending news for USA TODAY. Reach him at [email protected]