In 2009, Hopkins was one of nine astronauts selected by NASA as part of
NASA Astronaut Group 20. He began training alongside his Group mates and five international mission specialists later that year at the
Johnson Space Center. He completed his training in November 2011 after two years of scientific and technical briefings, intensive instruction in International Space Station systems, spacewalks, robotics, physiological training,
T-38 flight training, and water and wilderness survival training. Following the completion of his astronaut training, Hopkins became available to work other jobs in the NASA Astronaut Office, as well as being eligible for a future flight assignment.
Expedition 37/38 In February 2011, Hopkins was assigned to the crew of ISS
Expedition 37/
38, becoming the first member of his astronaut class to be given a flight assignment. He began training alongside Russian cosmonauts
Oleg Kotov and
Sergey Ryazansky for a long-duration flight to the Space Station. On September 25, 2013, Hopkins, Kotov, and Ryazansky launched on board the
Soyuz TMA-10M spacecraft. The trio docked with the
International Space Station several hours later, joining the Expedition 37 crew, which included
Roscosmos cosmonaut
Fyodor Yurchikhin, NASA astronaut
Karen Nyberg, and
ESA astronaut
Luca Parmitano. Shortly before their arrival aboard the station, the existing crew had welcomed the
Orbital Sciences Corporation Orb-D1 mission, the first demonstration flight of Orbital's
Cygnus unmanned resupply spacecraft, flying under the
Commercial Resupply Services contract. Following the departure of
Soyuz TMA-09M, carrying Yurchikin, Nyberg, and Parmitano, Hopkins and his two crewmates joined the Expedition 38 crew, with Kotov taking over as Station commander. Just prior to the departure of Soyuz TMA-09M, they had been joined by the remaining three Expedition 38 crew members: Roscosmos cosmonaut
Mikhail Tyurin; NASA astronaut
Rick Mastracchio; and
JAXA astronaut
Koichi Wakata, who had arrived aboard
Soyuz TMA-11M. This unusual "direct handover" was in order to allow the crew of Soyuz TMA-11M to bring up an
Olympic torch, to be returned by the crew of Soyuz TMA-09M days later as part of the
Olympic Torch Relay for the
2014 Winter Olympics in
Sochi, Russia. During Expedition 38, Hopkins participated in two spacewalks, alongside Mastracchio, lasting 5 hours and 28 minutes and 7 hours and 30 minutes, respectively. During the spacewalks, Mastracchio and Hopkins performed maintenance and upgrades on the exterior of the station. Also during ISS-38, Hopkins was aboard the station for the berthing and release of
Cygnus CRS Orb-1, the first operational flight of the Cygnus spacecraft. Hopkins and his two crewmates departed the station aboard Soyuz TMA-10M on March 10, 2014, leaving Tyrin, Masstrachio, and Wakata aboard the station as the initial crew of
Expedition 39. The trio landed in
Kazakhstan less than five hours later, ending a 166-day spaceflight.
Expedition 64/65 In August 2018, Hopkins and
Victor Glover were assigned to fly on
SpaceX Crew-1, the first operational mission to the
International Space Station of the SpaceX
Crew Dragon as part of NASA's
Commercial Crew Program. The two were later joined by NASA astronaut
Shannon Walker and JAXA astronaut
Soichi Noguchi in March 2020. On November 15, 2020, Hopkins, Glover, Walker, and Noguchi launched on
Crew Dragon Resilience, arriving at the Station two days later, on November 17. On February 1, 2021, on the second spacewalk of the mission, and his fourth spacewalk overall, also with Glover, Hopkins replaced a broken external camera, upgraded two other cameras, and concluded a four-year campaign initiated by
Shane Kimbrough and
Peggy Whitson on
Expedition 50 to replace the station's batteries. Crew-1 splashed down in the
Gulf of Mexico on May 2, 2021 after 167 days in space.
Retirement In June 2023, NASA announced that Hopkins had retired. In September 2024, Hopkins appeared as a commentator during
SpaceX's live coverage of the
Polaris Dawn spacewalk. In April 2026, he appeared again as a commentator during
CBS News' live coverage of the
NASA Artemis II mission, alongside fellow former NASA astronauts
Peggy Whitson and
Nick Hague. ==Personal life==