Final iROSA array can boost ISS power by as much as 30%

Because sunlight energizes the arrays, the astronauts waited for the station to enter Earth’s shadow before inspecting the connectors. They used the delay to clean the worksite and return Canadarm2 to its parking position. Ground readings then showed good current, and Stilwell gave the go-ahead to deploy.

How did the array unfold without a motor?

After releasing two bolts, Menon and Kutryk watched the array extend to its full 63-foot (19-meter) length. Deployment took about 10 minutes and required no motor: rolled carbon-composite booms released their stored potential energy, or energy held in the rolled structure, to extend the array.

Menon said the outing completed one array and, after more than 15 years of development, all eight. He praised the new arrays, saying they were half the size of the old ones and brought 40% more power.

How was the eight-array rollout completed?

SpaceX Dragon cargo spacecraft delivered each iROSA and its mounting assembly to the station. Beginning in June 2021, four pairs of astronauts deployed the units across four power channels:

• Joshua Kutryk of the Canadian Space Agency and NASA’s Anil Menon deployed arrays on channels 2A and 3B.
• NASA’s Shane Kimbrough and the European Space Agency’s Thomas Pesquet handled channels 2B and 4B.
• NASA astronauts Josh Cassada and Frank Rubio handled channels 3A and 4A in December 2022.
• NASA astronauts Steve Bowen and Woody Hoburg handled channels 1A and 1B in June 2023.

Why did the ISS need more power?

Flight controllers discovered the need for augmentation when the ISS’s eight original solar arrays began losing power output after exceeding their 15-year design life. The iROSAs provide the additional electricity needed to support ISS operations through retirement and a controlled deorbit, a planned guided descent from orbit, currently scheduled for late 2030.

What did the spacewalk mean for station history?

Menon’s career total reached 33 hours and 30 minutes across four spacewalks. Kutryk reached 14 hours and 10 minutes across two.

Thursday’s outing counted as the 101st U.S. EVA at the ISS without a space shuttle present and the 286th overall supporting assembly, maintenance and upgrades. NASA counted it as the ninth spacewalk of 2026 and the sixth conducted by Expedition 75’s resident crew.

Stilwell congratulated the pair after the station surpassed 26 years of continuous human presence. She called their work among the most difficult and dangerous tasks humans perform in space, said they made it look easy, and praised the execution as a demonstration of humanity at its best.

With all eight iROSAs deployed, the project has completed its planned array rollout. The extra capacity supports ISS operations through the retirement and controlled deorbit scheduled for late 2030.