Astronauts Complete the ISS's 100th U.S. Spacewalk, Installing a Seventh New Solar Array

The International Space Station's power upgrade is one spacewalk from done. NASA astronaut Anil Menon and Canadian Space Agency astronaut Joshua Kutryk exited the station's Quest airlock at 7:57 a.m. EDT on Thursday, October 29, and spent 7 hours and 11 minutes installing and deploying a new roll-out solar array, returning inside at 3:08 p.m. EDT. It was U.S. spacewalk 100 from the station — and the 285th spacewalk overall in support of station assembly, maintenance and upgrades.

The array they installed is the seventh of eight International Space Station Roll-Out Solar Arrays, known as IROSAs, mounted on the station's 2A electrical power channel. One installation remains: the eighth and final array, planned for a spacewalk on November 5 on the 3B channel, which Menon and Kutryk also prepared equipment for before coming back inside.

The station's original solar wings have been in orbit for years beyond their design debut, and their output has faded with age. The roll-out arrays are installed in front of the older wings, supplementing them rather than replacing them outright — each new blanket unrolls across part of an existing wing and feeds the same power channels with fresh capacity.

The arithmetic is significant. NASA says that with all eight roll-out arrays installed, the station's available power generation could rise by up to 30 percent — from about 160 kilowatts to roughly 215 kilowatts. That power supports the station's critical operations today, and, as NASA puts it, its eventual safe and controlled deorbit at the end of its life: even a retiring station needs electricity to leave orbit on purpose rather than by accident.

The pairing mixed experience by design. Menon, wearing the suit with red stripes as crew member 1, was on his fourth spacewalk. Kutryk, in the unmarked suit, was on his first — a milestone for the Canadian Space Agency, whose astronaut was working on a power truss built around the station's Canadian robotic arm heritage while colleagues and ground teams in Canada supported the outing.

First spacewalks are carefully choreographed, and this one had a full script: secure the new array, deploy it, and then get ahead of the next job by preparing the final array's worksite on the 3B channel. Completing the prep work is what makes the November 5 finale a single-spacewalk finish rather than the start of another pair.

The last roll-out array goes in on Thursday, November 5, on the station's 3B power channel. When it is deployed, the multi-year IROSA upgrade is complete: eight new blankets across the station's power channels, and a grid restored to more power than the ageing original wings could still deliver on their own.

NASA plans live coverage of the November 5 spacewalk, as it provided for this one. If you watched Thursday's installation, the sequel is the rarer event — final spacewalks of a programme are the ones history keeps. Mark the date the way the station crew marks a worksite: prepared in advance.

You do not need a spacewalk to watch the station work. The ISS circles Earth roughly every 90 minutes, and WorldEye's space station tracker follows its position live, while ISS over tells you when it will next pass over your location — bright, fast and unmistakable on a clear evening. Our guide to how to watch the ISS live covers the station's own Earth-viewing cameras and what its crew sees from 250 miles up.

Put the two together this week: track a pass over your house tonight, then tune in on November 5 as the crew finishes the job Thursday's walk set up. The station that flies over you will be flying on seven new wings — and, after next week, eight.