NASA Marks 100th US Spacewalk From the ISS With New iROSA Array

NASA astronaut Anil Menon and Canadian Space Agency astronaut Joshua Kutryk carried out the 100th US spacewalk staged from the International Space Station without a space shuttle docked to it. The excursion lasted 7 hours and 11 minutes and ended with a new solar array installed to boost the station's power supply.

Both are members of Expedition 75. They left and re-entered the station through the US airlock, Quest. It was the first spacewalk involving a Canadian astronaut since April 2019, when David Saint-Jacques worked outside alongside NASA's Anne McClain.

Installing the iROSA array

The pair removed the new foldable array, known as iROSA, from a temporary storage platform. It had arrived earlier in October aboard a SpaceX Dragon cargo spacecraft. Menon used the Canadarm2 robotic arm to move the roughly 340-kilogram array to the station's left side. There the two astronauts secured it over power channel 2A and connected its cables to the station's electrical system.

The array then unfurled to about 19 meters without a motor, driven by energy stored in its carbon-fiber composite booms. Mission control announced the start of deployment 4 hours and 23 minutes into the spacewalk, and it took about 12 minutes to open fully. Once deployed, it covers roughly half the area of a conventional solar array on the P4 truss.

Why it matters

The work is part of a power upgrade program. The station's eight original solar arrays have lost some efficiency after passing their 15-year design life. Operating alongside the older arrays, the iROSA units add 20% to 30% more electrical power, supporting current and future operations, including preparations for the station's safe, controlled deorbit, currently planned for 2030.

The astronauts also finished some tasks ahead of schedule. They removed several braces that hold the final solar array on the temporary platform and turned the launch locks used to secure it during transport aboard Dragon, preparing it for installation on the next outing.

It was Menon's fourth spacewalk and Kutryk's first, making him the fifth Canadian astronaut to take part in one. Menon's total time in open space on his current stay is now 26 hours and 31 minutes. The pair are due to go out again on November 5 to install the eighth and final array, completing the five-year power upgrade.