American astronaut Jeff Williams, alongside Oleg Skripochka and Alexey Ovchinin of Russia's space agency Roscosmos, safely returned home after accomplishing a 170-day mission aboard the International Space Station.

Williams, 58, now holds the US record for having spent the longest cumulative time in orbit. Aside from the mission whom he underwent with the Russian cosmonauts, he previously had four spaceflight missions. The retired Army colonel now has a total of 534 days, 2 hours and 48 minutes outside the Earth, beating the previous record of Astronaut Scott Kelyy, NBC News noted.

According to NASA's news release, commander of Expedition 48 Williams and cosmonauts Ovchinin and Skripochka landed their Soyuz TMA-20M spacecraft in Kazakhstan at 9:13 p.m. EDT. The Expedition 48 trio, who spent an estimated three hours flying back, was carried to a medical tent before being transported by a helicopter to Karaganda.

"The crewmembers' state of health is normal. The space travelers who have returned to Earth will undergo a medical check-up, after which Aleksey Ovchinin and Oleg Skripochka will be brought to Star City by plane, while Jeffrey Williams will take a flight to the US," Russia's Mission Control Center (MCC) told RIA Novosti, as quoted by RT.

Williams, the release added, has played a great role during his stay off the planet as he had undergone four missions. These included spacewalks with fellow NASA astronaut Kate Rubins to connect the first International Docking Adapter and to retrieve a spare thermal control radiator and install two new high-definition cameras.

He also helped carry out experiments that explored many fields of science aimed to human advancement. Williams, whose first flight in space was in 2000, is now 17th on the list of the world's most experienced astronauts and cosmonauts, Space Flight Now reports.

In an interview with CBS, Williams said that with or without the record, he still feels honored to be part of the International Space Station.

"What comes to mind is just the honor of being part of the International Space Station from the beginning all the way through the assembly to now, and working with this great team," he said. "I would say the partnership has never been stronger than it is today.