Soyuz Undocking Set for Sunday as Orbital Lab Researches Bioprinting and Health

The International Space Station will see a change of command on Saturday, with Expedition 74 leader Sergey Kud-Sverchkov handing over leadership to NASA flight engineer Jessica Meir. The ceremony, scheduled for 9:40 a.m. EDT, clears the way for Kud-Sverchkov and crewmates Chris Williams (NASA) and Sergei Mikaev (Roscosmos) to depart in the Soyuz MS-28 spacecraft. Undocking from the Rassvet module is planned for 3:03 a.m. EDT Sunday, with a parachute landing on the steppe of Kazakhstan at 6:25 a.m. EDT (3:25 p.m. local time).

Thursday’s activities focused on packing the Soyuz with return cargo, practicing computer-based landing procedures, and advancing a slate of microgravity research. Jessica Meir installed a specialized microscope in the Destiny lab to study disease progression, tissue development, and drug responses in space. She then mixed living cartilage cells with bioink and loaded a bioprinter, testing the feasibility of manufacturing viable tissues on demand — a technique with potential for both space medicine and terrestrial healthcare.

Other crew members supported spacesuit checks and human research. NASA’s Jack Hathaway, Anil Menon, and ESA astronaut Sophie Adenot inspected suit batteries, lights, and cameras. Menon also processed blood samples for an immune-function study, while Adenot continued workouts on a new European exercise device. Roscosmos crew collected air and surface samples for microbial analysis, and Anna Kikina measured microcirculatory blood pressure and exhalation rates as part of respiratory research.

The departure of the Soyuz will mark the official start of Expedition 75 under Commander Meir, who will lead the remaining seven-member crew through the end of summer.

What the Commander Change and Busy Science Day Tell Us About Station Life

A Routine Rotation with a Full Research Plate

The commander handover and Soyuz departure are part of a standard crew rotation — a choreographed relay that has kept the station continuously occupied for more than two decades. Such transitions are designed to leave no gap in station leadership, ensuring that the incoming commander is fully briefed and that critical systems remain supervised at all times.

The research highlights how the station’s role has matured from an engineering testbed to a full-time orbiting lab. Bioprinting cartilage and monitoring immune function are not novelty experiments; they feed into long-running investigations that could one day enable astronauts to produce medical supplies in deep space and better understand how microgravity alters cellular processes. The sheer volume of simultaneous studies — biology, physiology, materials, and microbial monitoring — reflects the station’s ability to host a diversified research portfolio that no single ground lab could replicate.

Spacesuit checks, meanwhile, are a reminder that the station remains an active platform for spacewalks, even during busy crew handover periods. The checkout of suit batteries, lights, and cameras suggests upcoming extravehicular activity planning, though no specific spacewalk date has been announced.