NASA astronaut Jessica Meir and European Space Agency (ESA) astronaut Sophie Adenot concluded a rare all-female spacewalk outside the International Space Station (ISS) on Tuesday, Sept. 1, 2026. The operation, designated as U.S. spacewalk 99, lasted 6 hours and 49 minutes, beginning at 8:40 a.m. Eastern Time and ending at 3:29 p.m. EDT, according to NASA.
This mission marked only the sixth-ever spacewalk exclusively featuring women and the first such event since May 2025, when NASA astronauts Anne McClain and Nichole Ayers exited the station during the Crew-10 mission, according to USA Today. The activity was the 284th spacewalk conducted in support of ISS assembly, maintenance, and upgrades.
Navigation and Maintenance Objectives
The duo performed several critical tasks to support the aging orbital outpost. They installed a new retroflector on the forward port of the Harmony module, a component designed to support spacecraft navigation during docking and rendezvous operations. Additionally, Meir and Adenot replaced a high-definition camera located on the station’s truss.
The astronauts also conducted scientific research by collecting a swab of the station’s exterior to analyze microorganisms. According to NASA, the crew began work to prepare for a future replacement of the Alpha Magnetic Spectrometer’s heat-rejecting radiator. However, Mission Control deferred the installation of the remaining guide studs for that radiator to allow engineers to develop a completion plan for a later date.
The crew also partially completed the installation of jumper cables for electrical systems. Due to the crew falling behind the established timeline, Mission Control shifted the completion of these cables and other noncritical tasks to a later date.
Equipment Malfunction and Resolution
During the EVA, Sophie Adenot encountered mobility issues involving her left arm. Jessica Meir inspected Adenot’s spacesuit and determined that the glove heater harness was likely getting caught, which restricted movement in the left shoulder joint. NASA reported that the issue appeared to be resolved by unzipping the joint before the astronauts entered the airlock.
Astronaut Milestones
The mission represented significant career milestones for both participants:
- Jessica Meir: This was Meir’s seventh spacewalk. She now ranks third all-time among women at NASA for total spacewalks, trailing only Suni Williams (9) and Peggy Whitson (10).
- Sophie Adenot: This was Adenot’s third spacewalk.
Context of Recent ISS Activities
The September 1 mission followed a series of recent activities in August. On Aug. 25, Sophie Adenot and NASA astronaut Anil Menon completed a 6-hour, 30-minute spacewalk (US EVA-98) to install and activate a spare Space-to-Ground Antenna (SGANT). That antenna is used for high-speed data transmission between the ISS and NASA’s Mission Control Center in Houston.
Prior to that, on Aug. 18, Adenot and Menon conducted US Spacewalk 97 to remove a failed antenna and install a spare. Earlier in the month, on Aug. 6, Jessica Meir and Anil Menon spent 6 hours and 27 minutes outside the station preparing the power system for the future installation of a roll-out solar array.
