When NASA astronaut Jeff Williams returned to Earth from the International Space Station on Sept. 6, he had been in space for 172 days. Adding those days to his three previous space flights, Williams has spent a total of 534 days off the planet, the longest for a NASA astronaut. The previous record holder, Scott Kelly, logged a three-flight total of 520 days.
Above: Jeff Williams monitors bowling ball-sized internal satellites known as SPHERES (Synchronized Position Hold, Engage, Reorient, Experimental Satellites) during a maintenance run in the International Space Station's Japanese Kibo Laboratory Module on June 30, 2016.
During his 172 days in orbit as Expedition 48 commander, Williams and others conducted hundreds of experiments and technology demonstrations.
Here, Williams works with NASA astronaut Kate Rubins, unseen, as they successfully installed a new international docking adapter on Aug. 19, 2016 during a five-hour and 58-minute spacewalk. The adapter will enable future crew vehicles from Boeing and SpaceX to dock at the station.
During his time on the space station, Williams dazzled those back on Earth with stunning images he posted to Twitter. Here, Williams captured the brilliant lights of an aurora on June 24, 2016, from the cupola, a seven-windowed dome that offers panoramic views of Earth.
The Soyuz TMA-19M capsule carrying Williams, Russian cosmonauts Alexey Ovchinin and Oleg Skripochka descends beneath a parachute near the town of Zhezkazgan, Kazakhstan, on Sept. 7, 2016.
From left, Jeff Williams and cosmonauts Alexey Ovchinin and Oleg Skripochka are viewed through the open hatch of the Soyuz capsule after landing.