4 organ-on-chip devices aboard Orion contain cells grown from each crew member's own bone marrow as part of the AVATAR (Virtual Astronaut Tissue Analog Response) experiment 1. Partners include BARDA, the NIH, and the Wyss Institute at Harvard. The chips are microfluidic devices that mimic human organ tissue at small scale. Exposing them to deep-space radiation alongside the crew members who donated the cells produces the first individualised dataset on how that radiation affects human biology. Previous space radiation studies relied on generic tissue samples or animal models. The data will inform dosage limits, shielding requirements, and medical protocols for longer missions. For a programme whose critics question its scientific return, these chips represent concrete research that could not be conducted anywhere closer to Earth.

Crew's Own Cells Fly to the Moon as Living Experiments
Organ-on-chip devices grown from each astronaut's bone marrow will produce the first personalised deep-space radiation data.
Personalised organ-on-chip experiments will yield the first individualised deep-space radiation data.
Deep Analysis
Each astronaut donated some of their bone marrow cells before the mission. Scientists grew those cells into tiny devices called organ-on-chips: microfluidic chips the size of a USB drive that mimic how human organs behave. These chips are flying alongside the crew members who donated the cells. When both are exposed to the same deep-space radiation environment, scientists can measure exactly how that radiation affects those specific people's biology, not a generic average. This matters because future missions to Mars will expose crews to far more radiation than any previous mission. Understanding individual variation in radiation tolerance could determine crew selection, mission duration, and medical protocols for those journeys.