Two NASA astronauts conducted a spacewalk on March 18, 2026, preparing a power channel on the International Space Station (ISS) for a future solar array installation. The event was the culmination of a series of scheduled activities that had been delayed due to a medical issue on the station.
The March 18 Spacewalk
Astronauts Jessica Meir and Chris Williams began their extravehicular activity (EVA) at approximately 8:00 a.m. EDT. The spacewalk was expected to last about 6.5 hours.
During the EVA, they worked to prepare one of the station's power channels for the future installation of an International Space Station Roll-Out Solar Array (iROSA).
This marked the fifth spacewalk for Meir and the second for Williams. Their previous EVA together occurred in March 2026 to prepare the station for a new solar array.
Previous Scheduled Spacewalks and Postponement
Prior to the March 18 spacewalk, NASA had scheduled two spacewalks for January 2026:
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January 8 (U.S. Spacewalk 94): Astronauts Mike Fincke and Zena Cardman were planned to exit the station's Quest airlock at 8:00 a.m. EST for approximately 6.5 hours. The primary objective was to prepare the 2A power channel for future iROSA installation. This event would have been Cardman's first spacewalk and Fincke's tenth, potentially tying Peggy Whitson's record for the most spacewalks by a NASA astronaut.
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January 15 (U.S. Spacewalk 95): A second spacewalk was scheduled to begin at 7:10 a.m. EST, with objectives including replacing a high-definition camera, installing a planar reflector navigational aid on the Harmony module, and relocating an early ammonia servicer jumper.
The January 8 spacewalk was postponed due to an undisclosed medical concern involving a crew member. Fincke later confirmed he was the astronaut who experienced the medical issue, stating his health status was stable. The prolonged medical issue subsequently led to the early departure of the SpaceX Crew-11 mission on January 15.
ISS Operations and Crew
The International Space Station has been in low-Earth orbit for over 25 years, typically at an altitude of approximately 260 miles. It orbits at about 17,500 mph, completing 16 orbits per day. The station is operated through a partnership involving NASA, Roscosmos, the European Space Agency (ESA), the Japan Aerospace Exploration Agency (JAXA), and the Canadian Space Agency.
As of the reporting period, the station's Expedition 74 crew includes:
- Crew-11: NASA astronauts Zena Cardman and Mike Fincke, JAXA astronaut Kimiya Yui, and Roscosmos cosmonaut Oleg Platonov. This crew launched on August 1, 2025, from the Kennedy Space Center aboard a SpaceX Dragon capsule. Their mission concluded with their departure on January 15, 2026.
- Crew-12: NASA astronauts Jessica Meir and Jack Hathaway, ESA astronaut Sophie Adenot, and Roscosmos cosmonaut Andrey Fedyaev. They arrived in February 2026.
- Soyuz MS-28: NASA astronaut Chris Williams and Roscosmos cosmonauts Sergey Mikaev and Sergey Kud-Sverchkov. They arrived in late November 2025.
Spacewalk History and Future Plans
To date, 279 spacewalks have been conducted outside the ISS. The March 18 EVA was the 279th spacewalk and the first of 2026 for Expedition 74.
NASA has announced that additional spacewalks with similar objectives for preparing solar arrays are planned. The ISS is scheduled to be deorbited in the coming years, a process that will be supported by the additional power provided by the new solar arrays.