NASA astronaut Sunita “Suni” Williams will retire in December 2025 after nearly three decades of service. A veteran of three space missions, she logged 608 days in orbit, led the ISS twice, and set records that continue to shape human spaceflight and future Artemis missions.​NASA astronaut Sunita “Suni” Williams will retire in December 2025 after nearly three decades of service. A veteran of three space missions, she logged 608 days in orbit, led the ISS twice, and set records that continue to shape human spaceflight and future Artemis missions.  ​ science