International Space Station Crew Expansion: NASA and Roscosmos Launch Thanksgiving Soyuz Mission with Unique Scientist-Astronaut

NASA astronaut Chris Williams made history on Thanksgiving Day 2025, launching aboard a Russian Soyuz spacecraft from the Baikonur Cosmodrome in Kazakhstan alongside cosmonauts Sergey Kud-Sverchkov and Sergey Mikaev. This mission underscores the enduring strength of international spaceflight collaboration, carrying a highly accomplished crew with unique scientific backgrounds to continue vital research aboard the International Space Station (ISS). The arrival of Williams and his crewmates marks a critical handover period for the orbiting laboratory, ensuring the continuity of its operations and scientific mission.

Thanksgiving Launch: A Mission of Science and Partnership

The Soyuz MS-28 spacecraft lifted off at 4:27 a.m. Eastern Time on November 27, 2025, a day when millions in the United States were preparing their holiday celebrations. The successful launch from the historic Baikonur Cosmodrome represented more than just the start of a routine resupply mission; it was a powerful symbol of international cooperation in space, a partnership that has remained steady on the technical and human level despite geopolitical tensions on Earth. For NASA, this flight was essential, continuing the agency’s uninterrupted presence aboard the ISS and ensuring an American astronaut was aboard the station at all times as part of the long-standing crew rotation agreement with Roscosmos.

The journey to orbit was a textbook example of Russian launch precision. Approximately nine minutes and forty-five seconds after liftoff, the Soyuz spacecraft separated from its rocket’s upper stage, deployed its twin solar arrays, and began its autonomous chase of the International Space Station. Using a highly efficient two-orbit, three-hour rendezvous profile, the Soyuz caught up with the orbiting complex and performed a smooth docking at the Earth-facing Rassvet module at 7:34 a.m. Eastern Time. This rapid transit from launch pad to station is a hallmark of Russia’s well-practiced Soyuz operations, minimizing crew time in the cramped capsule and allowing for a quicker start to the mission’s onboard work.

A Crew of Diverse Expertise

The three-person crew of Soyuz MS-28 is a blend of experience and fresh perspective, with each member bringing a critical skillset to the station’s operations.

The crew’s composition highlights the specialized training and cross-cultural teamwork required for modern spaceflight:

• Commander Sergey Kud-Sverchkov (Roscosmos): A veteran cosmonaut who served as a flight engineer on the ISS from October 2020 to April 2021, logging 185 days in space. His previous experience is invaluable for commanding the Soyuz spacecraft and mentoring his rookie crewmates during their initial days on the complex station.
• Flight Engineer Sergey Mikaev (Roscosmos): One of the two spaceflight rookies on this mission, Mikaev represents the new generation of Russian cosmonauts. His training has focused on the operational systems of both the Soyuz and the Russian segment of the ISS, where he will conduct maintenance and scientific experiments.
• Flight Engineer Chris Williams (NASA): A first-time flyer with an exceptionally unique background. Williams holds a Ph.D. in astrophysics from MIT and was a practicing medical physicist at Harvard Medical School before his astronaut selection. His expertise bridges fundamental science and applied human health, a perfect fit for the station’s research portfolio.

The Unique Journey of NASA’s Newest Space Station Scientist

Chris Williams’s path to becoming a NASA astronaut is a compelling narrative of intellectual curiosity and public service, defying the traditional stereotype of a career astronaut. An Eagle Scout and licensed private pilot, Williams began his academic career at Stanford University, where he earned a bachelor’s degree in physics. He then pursued a doctorate in astrophysics at the Massachusetts Institute of Technology (MIT), conducting research in radio astronomy. It was during this period that a chance observation led him down an unexpected parallel path.

“Down the street from my house, there was a volunteer fire department,” Williams recalled in a NASA interview. “And I was like, oh, that sounds like something that could be kind of fun and interesting to do.” He began volunteering, becoming trained as both an Emergency Medical Technician (EMT) and a firefighter. Williams found deep satisfaction in this work, appreciating the direct and immediate positive impact he could have on people’s lives, a contrast to the long-term, theoretical nature of astrophysics research.

This dual life as a graduate student and volunteer first responder took another pivotal turn as he was finishing his Ph.D. At a social gathering, Williams spoke with a physician who highlighted a significant need for physicists in medicine, particularly in the field of radiation oncology—using targeted radiation to treat cancer. Intrigued, Williams discovered that the complex mathematical principles and image processing techniques he used to create pictures of distant cosmic phenomena from radio telescope data were nearly identical to those used in advanced medical imaging, such as MRI and CT scans.

Williams made the transition to medical physics, eventually joining the staff at Harvard Medical School as a clinical physicist and researcher. He applied his analytical skills to ensure the precise and safe delivery of radiation therapy to cancer patients. It was from this position of applied science that NASA selected him for its 2021 astronaut candidate class. Williams is the second astronaut from that class to fly, and his assignment to a long-duration ISS mission so soon after training underscores NASA’s high regard for his unique scientific blend of cosmic understanding and human health expertise.

Seamless Integration into the Orbiting Laboratory

Upon opening the hatches and floating into the International Space Station, Williams, Kud-Sverchkov, and Mikaev were greeted by the seven crew members already living and working aboard. The expanded team of eleven represented a true multinational effort, including NASA’s Crew-11 commander Zena Cardman and astronaut Michael Fincke, Japanese Aerospace Exploration Agency (JAXA) astronaut Kimiya Yui, and Roscosmos cosmonaut Oleg Platonov, among others. This gathering of spacefarers from the United States, Russia, and Japan for a traditional welcome ceremony is a ritual that reinforces the collaborative spirit of the ISS program.

The newcomers immediately began a period of intensive onboarding, known as “handover.” This critical week-long process involves safety briefings, system familiarization tours, and detailed technical discussions with the crew they are replacing. The outgoing crew, Soyuz MS-27 commander Sergey Ryzhikov, flight engineer Alexey Zubritsky, and NASA astronaut Jonny Kim, who arrived last April, are responsible for passing on the institutional knowledge of the station’s current status, ongoing experiments, and any minor technical quirks. This ensures mission continuity and safety before the departing trio boards their own Soyuz spacecraft for the return to Earth on December 9.

The Science Mission Ahead

Williams’s primary role during his planned eight-month expedition will be as a scientist-in-residence. The International Space Station functions as a unique microgravity laboratory, enabling research impossible to conduct on Earth. Williams’s background makes him exceptionally well-suited for experiments across multiple disciplines.

Key areas of research he will support include:

• Human Health and Biology: Studying the long-term effects of microgravity on the human body, including bone density loss, muscle atrophy, and vision changes, to prepare for future missions to the Moon and Mars. His medical physics background will be crucial for experiments involving human physiology and radiation monitoring.
• Material Science and Physics: Investigating fluid dynamics, combustion, and the behavior of materials in weightlessness. These experiments can lead to improvements in manufacturing processes, energy production, and consumer goods on Earth.
• Earth and Space Science: Using the station’s external platforms to monitor climate change, observe astronomical phenomena, and study cosmic rays. His doctorate in astrophysics will provide deep insight into these payloads.
• Technology Demonstration: Testing new life support systems, robotics, and other technologies that will be essential for deep space exploration.

“I’ve got a lot of different goals,” Williams said, “but I think the biggest one… is to truly be able to put my training into practice and to do a really good job to push forward the science and research that we’re doing on the space station.”

The Enduring Framework of U.S.-Russia Space Cooperation

The launch of an American astronaut on a Russian vehicle on an American holiday is the latest chapter in a complex but resilient partnership that dates back to the Apollo-Soyuz Test Project of 1975. The current Integrated Crew Agreement between NASA and Roscosmos, established after the retirement of the Space Shuttle, ensures both nations always have a trained crew member aboard the ISS. This “crew swap” system is a pragmatic necessity: it guarantees both sides can operate their respective segments of the station and provides assured crew transportation should either American or Russian spacecraft be grounded for an extended period.

This interdependence was thrown into sharp relief in 2022 following Russia’s invasion of Ukraine. While diplomatic and economic relations between the two nations deteriorated severely, the operational partnership in space largely continued, guided by the mutual need to maintain the $100-billion-plus International Space Station. Both agencies have repeatedly stated that the ISS remains a professional, working-level collaboration isolated from politics. The successful launch of Soyuz MS-28 is a tangible demonstration that this professional framework, though strained, remains functionally intact for the time being.

Looking ahead, the future of this cooperation is uncertain. NASA is now heavily invested in the Commercial Crew Program, with SpaceX’s Crew Dragon routinely flying astronauts and Boeing’s Starliner preparing for operational missions. Russia has announced intentions to build its own orbital station after the planned retirement of the ISS around 2030. However, for the remainder of this decade, the integrated crew agreement is expected to continue, with occasional seat barters ensuring a balanced presence. Missions like Soyuz MS-28 prove that even in an era of renewed national space programs, practical international cooperation in low-Earth orbit remains not just possible, but essential for ongoing scientific discovery.

A Day in the Life: Work, Maintenance, and Wonder

For Chris Williams and his crewmates, life on the ISS follows a highly structured schedule, typically planned down to five-minute increments by teams of planners on the ground. A standard “work day” in space lasts approximately 12 hours, from wake-up to sleep time, and is filled with a diverse mix of tasks. The crew’s responsibilities are a balance between executing the station’s core scientific mission and performing the endless upkeep required to keep the complex machine running.

Williams will spend a significant portion of his time conducting and monitoring the hundreds of experiments active during his expedition. This can involve setting up hardware, manipulating samples, capturing microscopy images, or speaking directly with scientists on Earth via video link. As a trained scientist, he is not just a technician following procedures; he is expected to use his judgment to troubleshoot experiments, note unexpected observations, and ensure the integrity of the data being sent back to researchers worldwide.

Equally important is the work of station maintenance. The ISS is a technological marvel, but it is also a aging machine in a harsh environment. Crew members regularly perform system checks, replace filters, upgrade software, and repair equipment. They also dedicate two hours each day to mandatory exercise using specialized resistive and aerobic equipment to combat the muscle and bone loss caused by microgravity. Williams’s background as an EMT and firefighter—requiring calm problem-solving under pressure—will be a tremendous asset during routine maintenance or the rare instance of an emergency alarm.

Amid the busy schedule, crews are encouraged to take moments for personal time, to communicate with family, and to simply look out the Cupola window at the Earth passing below. These moments of awe are often cited by astronauts as a profoundly transformative aspect of spaceflight, providing perspective and mental respite. Williams will also participate in educational outreach events, speaking to students and the public from orbit to share the experience and inspire the next generation.

The Road Home and the Legacy of Expedition 71/72

Williams, Kud-Sverchkov, and Mikaev are scheduled to live and work aboard the ISS as part of Expedition 71 and 72 until approximately July 2026. Their mission will overlap with several crew rotations. The Crew-11 team that welcomed them is slated to depart in February or March 2026, after the arrival of their replacements, SpaceX’s Crew-12 mission. Later in 2026, a new trio will launch on Soyuz MS-29 to replace the MS-28 crew, who will then board their own Soyuz for the return journey.

Landing in the steppes of Kazakhstan is a dramatic and physically demanding process. After undocking, the Soyuz performs a deorbit burn, plunges into the atmosphere enduring intense heat, and finally deploys parachutes for a jarring, parachute-and-retro-rocket-cushioned touchdown. Recovery teams immediately assist the crew, who must readjust to gravity after months in weightlessness. For Williams, the return will mark the end of an intense personal and professional journey and the beginning of a lengthy period of post-flight medical evaluation and rehabilitation.

The legacy of this mission will be measured in the data it produces. Every experiment Williams conducts, every system he helps maintain, and every observation he makes contributes to humanity’s collective knowledge. His unique path—from stargazer to healer to explorer—embodies the interdisciplinary spirit of the ISS. The research he supports will advance our understanding of human health for spacefarers and Earthlings alike, improve fundamental scientific knowledge, and test the technologies that will carry humans farther into the solar system.

Looking Beyond: The Future of Space Station Research

As the ISS program enters its final planned years, missions like Williams’s are crucial for maximizing the return on this unparalleled global investment in science. The station is currently approved to operate until 2030, with a planned deorbiting process into a remote area of the Pacific Ocean around 2031. This timeline puts a premium on the research conducted today, as it lays the groundwork for the next era of space exploration.

NASA and its international partners are already shifting focus toward the Moon through the Artemis program, which aims to establish a sustainable human presence on the lunar surface as a stepping stone to Mars. The lessons learned from the ISS about long-duration life support, crew health, and international operational protocols are directly informing the design of the Lunar Gateway, a planned small station in orbit around the Moon. The work of astronauts like Chris Williams in maintaining human health and conducting complex science in microgravity is proving that humans can not only survive, but thrive and do meaningful work in space for extended periods.

The future will likely see a mix of government-led outposts like the Gateway and commercial, free-flying space stations. Several American companies are already developing successors to the ISS, with plans to host both NASA-sponsored research and private-sector activities. The democratization of space access promises an acceleration of discovery. The foundational role of the International Space Station, and the crews who have lived aboard it, will be remembered as the critical proving ground that made all future deep-space ambitions possible.

Conclusion

The Thanksgiving Day launch of NASA astronaut Chris Williams aboard a Russian Soyuz spacecraft stands as a significant milestone in the ongoing story of human spaceflight. It reaffirms the durable, if complicated, operational partnership between the United States and Russia that has sustained the International Space Station for over two decades. More than a symbolic gesture, the mission is a vital operational link in the crew rotation chain, ensuring the continuity of human presence and scientific research in low-Earth orbit.

Williams’s personal journey from astrophysicist and medical physicist to space explorer highlights the evolving and interdisciplinary nature of modern astronaut selection, where diverse expertise is valued as highly as traditional piloting skills. During his eight-month expedition, the research he conducts will contribute to advancements in medicine, materials science, and our understanding of the universe, while also preparing humanity for the next giant leaps to the Moon and beyond. As the ISS program approaches its conclusion, missions like Soyuz MS-28 maximize the scientific return of this unique orbital laboratory, cementing its legacy as the indispensable foundation for all future human exploration of deep space.