Fig. 3: Study timeline.

Mice arrived at the Kennedy Space Center (KSC) 14 days prior to launch (L−14d) and were allowed to acclimate to the spaceflight hardware. The Flight groups had their surgeries performed 4 days before launch (L−4d) and 2 days prior to launch they were loaded into spaceflight hardware (Transporters) and loaded onto the SpaceX Dragon Capsule (L−2d). One day after launch asynchronous Earth groups were submitted to identical surgeries (L + 1d). To match the spaceflight conditions, two days after Earth group surgeries, mice were loaded into spaceflight Transporter hardware (L + 3d). Five days after launch, spaceflight mice were transferred by astronauts into the Habitat spaceflight cages aboard the International Space Station, where the mice remained for the study duration (L + 5d). To keep the 5-day asynchronous timing, 10 days after launch, Earth-based mice were transferred into Habitat spaceflight cages at KSC. Four weeks post-surgery euthanasia of mice began over a 5-day period, due to the significant time it takes astronauts to complete these tasks (L + 24d for the Flight groups and L + 28d for the Earth groups).