Updated on: November 27, 2025 / 5:52 AM EST / CBS News
American astronomer-turned-medical physicist and now NASA astronaut Christopher (Chris) Williams joined two Russian cosmonauts aboard a Soyuz ferry Thursday for a Thanksgiving Day flight to the International Space Station.
With commander Sergey Kud-Sverchkov at the controls of the Soyuz MS-28/74S spacecraft, flanked by flight engineer Sergey Mikaev on his left and Williams on his right, the crew’s Soyuz 2.1a booster ignited at 4:27 a.m. Eastern and lifted off from the Baikonur Cosmodrome in Kazakhstan. Nine minutes and 45 seconds later, the Soyuz separated from the booster’s upper stage, its two solar arrays deployed, and the crew began pursuing the station. An automated two-orbit rendezvous was planned to conclude with docking at the ISS Earth-facing Rassvet module at 7:38 a.m. Eastern.
Williams, a former volunteer firefighter and emergency medical technician who earned a Ph.D. in astrophysics from MIT, was a board-certified medical physicist at Harvard Medical School when selected for NASA’s astronaut corps in 2021. He is the second member of that astronaut class to fly. Williams and Mikaev were making their first spaceflight on this mission; Kud-Sverchkov is a veteran who logged 185 days aboard the station in 2020–2021.
Williams described the crew as “really great,” praising the two Sergeys as kind, intellectually curious and engaging, and said he enjoyed training with them both in Russia’s Star City and in Houston.
The Soyuz MS-28 crew will replace Soyuz MS-27/73S commander Sergey Ryzhikov, flight engineer Alexey Zubritsky and NASA astronaut Jonny Kim, who launched to the station last April and plan to return to Earth Dec. 9 after an eight-month stay.
Onboard the station to greet Williams and his crewmates are NASA Crew 11 commander Zena Cardman, Michael Fincke, Japanese astronaut Kimiya Yui and cosmonaut Oleg Platonov. That crew launched on a SpaceX Falcon 9 in August and plans to return in February or March after Crew 12 arrives. All 11 station residents were scheduled to join a traditional welcome video call with mission managers and family in Moscow, followed by a safety briefing and familiarization with the station’s systems.
Williams’ background includes a bachelor’s degree in physics from Stanford University, radio astronomy research en route to his doctorate, and volunteer service as an EMT and firefighter during graduate school. While finishing his Ph.D., a conversation with a physician steered him toward medical physics and radiation oncology, where he became a clinical physicist and researcher on staff at Harvard Medical School.
He noted that many imaging and image-processing techniques from radio astronomy apply directly to medical imaging, a connection that helped motivate his career shift before joining NASA.
Williams is an Eagle Scout and holds a private pilot’s license. He said the Russian spacecraft training was challenging mainly because of extensive travel and credited his wife, Aubrey, with helping keep family life steady through the process. He said his primary goal during the planned eight-month stay is to put his training into practice and advance the science and research conducted aboard the space station, calling the work important, interesting and inspiring.
