Expedition 74 Crew Focuses on Vestibular Science, Stem Cell Research, and ISS Logistics

The Expedition 74 crew aboard the International Space Station (ISS) concluded its first full operational week on December 12, 2025, balancing intensive human research with critical station maintenance and logistics. The expedition, which began on December 8, 2025, and is scheduled to continue through July 2026, highlights the ISS's ongoing importance as a platform for preparing for extended deep-space missions, including future Artemis endeavors to the Moon and Mars. The crew’s diverse activities spanned biomedical investigation, materials science, and life support upkeep, demonstrating the integrated nature of orbital operations.

Central to the scientific endeavors was a shared focus on human adaptation to microgravity, particularly concerning the vestibular system, which governs balance and orientation. NASA Flight Engineer Chris Williams participated in the CIPHER human research experiment, executing the vestibular component with remote guidance from mission control doctors while also assessing his cardiorespiratory fitness. Concurrently, Roscosmos Flight Engineers Sergey Kud-Sverchkov and Sergei Mikaev utilized different virtual reality goggles for their agency’s 'Virtual' experiment, tracking vision and gathering data on sensory interactions in weightlessness. NASA anticipates that CIPHER findings will refine astronaut training and benefit Earth-based balance therapies, while Roscosmos seeks to apply its data to crew re-adaptation protocols post-flight. The CIPHER suite comprises 14 studies designed to characterize the whole human response to long-duration missions, monitoring systems from the eyes to the brain.

In parallel biomedical research, NASA Flight Engineer Zena Cardman dedicated time to the StemCellEx-IP1 investigation, treating and preserving stem cells cultivated in orbit. This research aims to validate the potential superiority of space-manufactured cells over those grown on Earth, with the objective of advancing regenerative medicine for damaged tissues and organs. The microgravity environment on the ISS facilitates three-dimensional cell growth, which more closely mimics the native human body environment than the two-dimensional cultures typically used on Earth, potentially leading to improved cell production for clinical applications.

Logistical and maintenance tasks ensured the station's continued operational readiness. Station Commander Mike Fincke managed the complex process of loading cargo onto the Japanese HTV-X1 resupply craft, which is slated for disposal and departure in late January 2026. This vehicle, captured by Kimiya Yui using Canadarm2 on October 30, 2025, is the successor to the Kounotori series and has a capacity of up to 5.8 tons. Furthermore, Fincke performed necessary upkeep on the Tranquility module's waste and hygiene compartment, while Roscosmos Flight Engineer Oleg Platonov conducted orbital plumbing maintenance and measured his mass using a device based on Newton's Second Law. JAXA Flight Engineer Kimiya Yui also contributed by installing material sample carriers in the Kibo airlock for exposure to the vacuum, radiation, and extreme temperatures—research informing advanced life support systems for Artemis missions. Yui also installed and insulated an experimental carbon dioxide removal device within Kibo, a technology demonstration relevant for missions beyond low Earth orbit.