Astronauts install final ISS solar array, completing five-year power upgrade
A nearly seven-hour spacewalk by Anil Menon and Joshua Kutryk closes out an 18-EVA campaign that lifts the station's power output from 160 to 215 kilowatts — enough to sustain operations through its 2030 retirement.
NASA/External High Definition Camera Assembly / Wikimedia Commons
After nearly seven hours outside the International Space Station, NASA astronaut Anil Menon summed it up in four words: "We got it done!" The exclamation marked the end of a five-year campaign to re-power an aging orbital laboratory — and the installation of the eighth and final ISS Roll-Out Solar Array on Thursday, Nov. 5.
Today marks the completion of not just one solar array but, over 15 years after its development, eight arrays. These solar arrays are incredible. Half the size of the old ones and bringing 40% more power.— Anil Menon, NASA astronaut
Menon and Canadian Space Agency astronaut Joshua Kutryk, both Expedition 75 flight engineers, began their extravehicular activity at 8:36 a.m. EST and closed the hatch at 3:35 p.m. EST — a duration of six hours and 59 minutes. The pair worked on the starboard side of the station's backbone truss, targeting the 3B power channel, one week after they had installed the penultimate array on Oct. 29.
The job required a logistical workaround that the previous week's installation did not. The Canadarm2 robotic arm — operated from inside the station by NASA astronauts Luke Delaney and Jessica Watkins — lacks the reach to carry a crew member and the 750-pound (340-kilogram) array all the way to the far right end of the power truss. Instead, Menon and Kutryk passed the assembly between themselves leapfrog-style until it reached the waiting support frame.
Once mounted, Menon connected the power and data cables during an orbital night pass — a deliberate choice, since the arrays generate electricity whenever sunlight hits them. That precaution proved well-founded: as the station moved back into sunlight, flight controllers noticed something unexpected.
We are seeing half of the expected shunt current that we want. In this current config, we are not necessarily going to deploy.— Nichole Stilwell, NASA spacewalk officer, Mission Control
The crew used the unplanned pause productively — cleaning up the worksite and returning Canadarm2 to its park position — while waiting for the next orbital darkness to inspect the connectors. The fix worked.
We are seeing good shunt currents on the ground, so we are go for deploy.— Nichole Stilwell, NASA spacewalk officer, Mission Control
Kutryk released two bolts and the array began to unfurl on its own. No motor was involved: the iROSA, manufactured by Redwire Space, uses strain-energy stored in carbon composite booms to extend itself. The blanket reached its full 63-foot (19-meter) length in about 10 minutes.
The need for the upgrade traces back to the station's original solar wings, which have been operating since December 2000 — well past their 15-year design life. As they degraded, power output fell. The iROSAs were designed to mount directly in front of the original panels; even though they shade portions of the older arrays, they still deliver a net gain. Together, all eight bring total station power from roughly 160 kilowatts to approximately 215 kilowatts — a boost of up to 30%.
The campaign required 18 spacewalks in total, beginning in February 2021, and involved four pairs of astronauts across multiple station crews. Each array was delivered by a SpaceX Dragon cargo spacecraft and stowed until its installation crew was ready. Thursday's EVA was the 101st U.S. spacewalk conducted at the station without a space shuttle present, and the 286th overall in support of ISS assembly, maintenance, and upgrades.
For Kutryk — a Royal Canadian Air Force colonel from Fort Saskatchewan, Alberta — the milestone was personal as well as technical. His two spacewalks were the first by a Canadian since David Saint-Jacques went outside the station in 2019. His career total now stands at 14 hours and 10 minutes. Menon has now logged 33 hours and 30 minutes across four spacewalks.
Congratulations to you all on your stellar work to finish the last of the roll-out solar arrays and the upgrades to the ISS power system that will take it to the end of its journey. It is fitting that we just surpassed 26 years of constant human presence on the International Space Station, and you all showed us what the best of humanity looks like executing one of the most difficult and dangerous [things] humans do and making it look easy.— Nichole Stilwell, NASA spacewalk officer, Mission Control
The additional power is intended to sustain life support, computers, scientific research, and visiting vehicle operations through the station's planned retirement and controlled deorbit, currently scheduled for late 2030. NASA also says the iROSA technology provides data relevant to solar-power systems for future missions. Kutryk and his crewmates remain aboard the station, continuing research and maintenance work.
Why it matters — With the ISS's original solar arrays past their design life, this upgrade secures the power needed to keep the station — and its research — running until its planned 2030 retirement.
Reported by space.com, spaceflightnow.com, spacefoundation.org, cbsnews.com, nasa.gov, pv-magazine.com, netnewsledger.com
