NASA’s Artemis II, launched 1 April 2026, carried four astronauts on a 10‑day lunar flyby, pushing humans beyond low Earth orbit for the first time since Apollo. The mission focused on mapping deep‑space radiation, deploying cabin monitors, crew‑worn dosimeters, and German heavy‑ion detectors to gauge exposure inside Orion.

Radiation science in space demands more than a single dose number. By measuring trapped Van Allen particles, solar proton events, and galactic cosmic rays, Artemis II seeks to link physical dose rates—captured by linear energy transfer metrics—to biological markers. The mission’s AVATAR experiment tests bone‑marrow organ chips made from each crew member’s cells, while saliva and blood samples track immune responses.

These data will inform future crew protection strategies, revealing how shielding geometry, spacecraft orientation, and real‑time monitoring can mitigate hazards. The findings will set design standards for Orion and future crewed missions to the Moon and Mars, ensuring astronauts can operate safely in the harsh deep‑space environment.