Williams has spent a total of 362 days in space. Astronaut Scott Kelly holds the current American record for cumulative days in orbit: 534. Kelly racked up that total after spending a year aboard the station participating in experiments to see how humans react to long-duration spaceflight.

NASA expects Williams to break Kelly's record before returning to Earth with Skripochka and Ovchinin in September. Williams will tie Kelly's 534-day total on September 6.

Of Williams' Russian crewmates, only Skripochka has flown before, participating in Expeditions 25 and 26 in 2010 and 2011. Ovchinin, a rookie, will be in command of the trio's Soyuz TMA-20M spacecraft. The vehicle will dock with the station's space-facing Poisk module, which was left empty by the departure of the one-year crew on March 1.

Starting next week, the ISS is scheduled to receive two cargo spacecraft in nine days. On March 22, an Orbital ATK Cygnus freighter launches from Cape Canaveral aboard a United Launch Alliance Atlas V. And on March 31, a Russian Progress resupply ship will lift off from Baikonur. A SpaceX Dragon could also launch next month, but a NASA spokesperson said the date was still under review.

There are no spacewalks planned for Expedition 47. A second Dragon spacecraft will carry a new International Docking Adapter to the station as early as summer, and require a spacewalk for installation.