The 100-million-mile journey to prepare for Mars and the Moon

Space · Published 23 October 2026 Swipe more like this →

In short: Space exploration is less about the destination and more about the data gathered along the way. After 237 days in orbit, SpaceX Crew-12 is returning with critical insights on everything from heart health to stem cell production, providing the blueprint for humanity's next leap into the solar system.

The SpaceX Crew-12 mission, which concluded on October 8, 2026, served as a high-stakes laboratory for long-duration human spaceflight. During their 237-day stay aboard the International Space Station, the four-person crew—including NASA astronauts Jessica Meir and Jack Hathaway, ESA astronaut Sophie Adenot, and Roscosmos cosmonaut Andrey Fedyaev—traveled more than 100 million miles and completed over 3,792 orbits around Earth. This endurance was not merely a feat of logistics but a necessary window to observe the biological and mechanical stresses of life in microgravity.

The mission's scientific output targeted specific hurdles for deep-space travel. Key research included testing stem cell production for potential cell-based therapies and demonstrating on-demand IV fluid generation, a necessity for self-sufficiency on long voyages. Furthermore, the crew investigated the long-term heart damage caused by pneumonia-inducing bacteria and studied how physical characteristics influence blood flow during spaceflight. These studies are vital for maintaining astronaut health during the multi-year journeys required to reach the Moon or Mars.

Beyond the immediate science, the mission highlights the industrial and international cooperation required to sustain human presence in Low Earth Orbit. NASA Administrator Jared Isaacman emphasized that the success of Crew-12 relies on the expertise of thousands across NASA, SpaceX, and international partners. By refining the capability to transport crew and maintain critical assets repeatedly, these missions provide the risk-reduction data and engineering confidence needed to transition from orbiting Earth to exploring the wider solar system.

The crew's return marks a significant milestone in the transition toward permanent off-world presence. While the mission was the second for Meir and Fedyaev, it was a debut for Hathaway and Adenot, showcasing the rotating expertise of the international community. Each orbit contributes to a cumulative body of knowledge that moves humanity closer to becoming a multi-planetary species.

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