Originally NASA Astronaut Jeanette Epps was assigned as flight engineer for Expeditions 56 and 57, becoming the first African American space station crew member[7] and the 15th African American to fly in space, but on January 16, 2018, NASA announced that Epps had been replaced by her backup Serena M. Auñón-Chancellor with no announced explanation as to why.[8][9]
Feustel and Arnold installed new high-definition cameras near IDA 2 mated to the front end of the station's Harmony module. The additions will provide enhanced views during the final phase of approach and docking of the SpaceX Crew Dragon and Boeing CST 100 Starliner commercial crew spacecraft that will soon begin launching from American soil.
The astronauts also swapped out a camera assembly on the starboard truss of the station used to film NASA TV and closed an aperture door on the CATS experiment outside the Japanese Kibo module in preparation for disposal on SpaceX CRS 15 and replacement by its successor, ECOSTRESS. Get aheads involved relocating an adjustable grapple bar to the S1 Truss and securing the Flex Hose Rotary Coupler in preparation for replacement on the next spacewalk. During the spacewalk Feustel beat Jerry Ross, his STS 125 crewmate Dr. John Grunsfeld, Fyoder Yurchikhin, and Peggy Whitson to become third on the list of all time space walkers.[10]
The cosmonauts launched four cubesats and installed the Icarus experiment. Spacewalk fell behind schedule when Icarus failed to seat properly putting the spacewalk 90 minutes behind schedule and calling for an hour extension. The cosmonauts finished the spacewalk by retrieving experiments from the Pirs docking compartment and Poisk module[11]
On August 29, 2018, a small leak was detected through a drop in air pressure by the flight controllers. After learning about the leak upon waking up, the astronauts discovered a 2 mm hole in the orbital module of the Soyuz MS-09 spacecraft. The hole was initially repaired with tape, followed by a permanent repair with gauze and epoxy.[12][13]