ALT The 10 members of NASA’s 2025 Astronaut Candidate Class pose with rock samples collected during their geology training at the Rio Grande del Norte National Monument, New Mexico. Credit: NASA/Helen Arase Vargas

ALT NASA astronaut and Expedition 74 flight engineer Jessica Meir’s reflection is captured in a spacesuit helmet visor. The visor assembly is coated with a microscopic layer of gold that reflects infrared radiation to protect an astronaut’s eyes while allowing visible light to pass through. Meir was working inside the International Space Station's Quest airlock, installing leg and arm components on the spacesuit and swapping components from one suit to another. Credit: NASA/Jack Hathaway

ALT NASA astronaut and Expedition 74 flight engineer Jessica Meir processes stem cell samples inside the Life Science Glovebox aboard the International Space Station’s Kibo laboratory module. Meir nourished the stem cells being incubated to learn how to manufacture space-designed therapies to treat cancer and blood conditions. Credit: NASA/Jessica Meir

ALT NASA astronaut and Expedition 74 flight engineer Jessica Meir is pictured outside of the International Space Station during a seven-hour-and-20-minute spacewalk to replace a malfunctioning wrist joint on the Canadarm2 robotic arm. Credit: NASA/Chris Williams

ALT NASA astronaut Jessica Meir poses for a portrait inside the Kibo laboratory module after acccepting command of the International Space Station from Roscosmos cosmonaut Sergey Kud-Sverchkov (out of frame). Meir will lead the Expedition 75 crew until the end of summer. Credit: NASA/Anil Menon