Vande Hei boarded the Russia Soyuz MS-19 spacecraft on Wednesday with Russian cosmonauts Anton Shkaplerov and Pyotr Dubrov.
The trip is an example of increasing rare US-Russian cooperation after the Russian invasion of Ukraine and Western retaliatory sanctions severed many of the ties between the two.
The spacecraft undocked from the ISS at 3:21 a.m. ET and was on its way back to Earth at the time of publication.
Vande Hei’s record-breaking achievement was marred by raised tensions between Russia and the US.
A heavily edited video aired by the State-Owned RIA Novosti and shared by NASA Watch on March 5 hinted at the possibility that Russia could refuse to return Vande Hei to Earth, stranding him in orbit.
It showed Russian cosmonauts seemingly waving goodbye at Vande Hei before boarding a shuttle departing from the ISS.
Rogozin, however, said on March 11 that Vande Hei would come back to Earth as planned, and dismissed what he called “hysterical” news reports suggesting otherwise, per Space.com. NASA also confirmed the return would proceed as normal.
Vande Hei’s trip broke the longest spaceflight record previously set by Kelly in 2016 by 15 days. During his trip, he studied muscle loss in space, kidney health, and fire safety among other topics, as shown in a tweet below.
Roscosmos cosmonaut Anton Shkaplerov handed over command of the ISS to NASA astronaut Tom Marshburn on Tuesday in a collegial ceremony, during which he said the crew “worked together very hard.”
“We worked very hard, like one crew, and we did not have problems,” he said.