Expedition 55 began with the undocking of the Soyuz MS-06 spacecraft from the International Space Station (ISS) on February 27, 2018. Expedition 54 commander, Alexander Misurkin (RSA), and flight engineers Joseph Acaba (NASA) and Mark Vande Hei (NASA) returned to Earth, leaving behind Expedition 55 commander Anton Shkaplerov (RSA), and flight engineers Scott Tingle (NASA) and Norishige Kanai (JAXA).
The Expedition 55 crew was later expanded to six with the arrival of crewmates Andrew Feustel (NASA), Oleg Artemyev (RSA), and Richard Arnold (NASA). Launch occurred on March 21, 2018 with arrival at the ISS two days later.
In addition to operating and maintaining the station, crewmembers performed hundreds of technological demonstrations and science research experiments. The crew received tons of supplies from visiting resupply vehicles and performed several challenging spacewalks. Also, Ricky Arnold participated in several dozen educational events, continuing the Year of Education begun by Joe Acaba.