NASA has completed the final stage of a multi-year upgrade to the International Space Station’s electrical power system, installing the eighth and last roll-out solar array during a nearly seven-hour spacewalk on November 5.
The installation brings the station’s reported power-generation capacity from approximately 160 kilowatts to 215 kilowatts, an increase NASA describes as about 30%. The work was carried out by NASA astronaut Anil Menon and Canadian Space Agency astronaut Joshua Kutryk during Expedition 75.
The milestone completes the installation phase of the International Space Station Roll-Out Solar Array (IROSA) program. Following the spacewalk, the crew turned to equipment recovery, spacesuit maintenance, biomedical research and routine station inspections.
Eight arrays complete the station’s power upgrade
The final IROSA was installed on the station’s 3B electrical power channel, on the starboard side of its truss structure.
Menon and Kutryk completed the spacewalk at 3:35 p.m. Eastern Standard Time on November 5. NASA reported a total excursion duration of six hours and 59 minutes.
The operation was the 101st U.S. spacewalk and the 286th spacewalk conducted in support of space station assembly, maintenance and upgrades. It was Menon’s fifth spacewalk and Kutryk’s second.
The final installation followed another spacewalk on October 29, when the astronauts deployed the seventh IROSA on the station’s 2A electrical power channel. Together, the two operations completed the remaining installation work for the eight-array upgrade.
NASA said the broader power augmentation effort required 18 spacewalks to prepare electrical power channels and install the arrays. Work began in 2021 and extended across several years of station maintenance and upgrades.
Why NASA needed additional electrical capacity
The International Space Station depends on electricity for nearly every aspect of its operation.
Power supports environmental control and life-support equipment, communications, onboard computing, scientific experiments, lighting, thermal management and other systems required to keep the orbital laboratory operating.
The station’s original solar power infrastructure has supported decades of research and crew operations. However, aging equipment and changing operational requirements have made power-system upgrades an important part of maintaining the outpost.
The IROSA program adds generating capacity without requiring the replacement of the station’s entire existing solar array infrastructure.
NASA first tested the roll-out solar array technology aboard the station in 2017. Its compact design allows the array to be launched in a relatively small cylindrical package before unfurling after installation. This reduces the mass and volume required during launch compared with transporting an equivalent deployed structure.
The arrays supplement the existing solar power system rather than replacing it. This approach allows NASA to increase electrical generation while continuing to use the station’s established power infrastructure.
What the 215-kilowatt capacity means
NASA reports that the completed installation increases the station’s power-generation capacity from approximately 160 kW to 215 kW.
ISS electrical power capacity
Figures reported by NASA. The bars illustrate the relative capacity figures, not real-time electrical output.
The additional capacity provides greater electrical headroom for station operations and research activities. It also supports NASA’s longer-term station management requirements, including the planning and execution of a safe, controlled deorbit.
However, installed generation capacity should not be confused with continuously available electrical power. Actual output depends on factors such as orbital sunlight exposure, energy storage, distribution and system operating conditions.
NASA has not provided a breakdown in the November 6 update showing how the additional capacity will be allocated among individual experiments or station systems.
Spacewalk completion followed by routine maintenance
The November 6 NASA update also documented the work required after the final array installation.
Menon and Kutryk reconfigured their spacesuits, refilled the suits’ water tanks, removed air bubbles from the tanks and installed rechargeable batteries. They also inspected and secured the tools and equipment used during the spacewalk inside the Quest airlock.
NASA flight engineers Jessica Watkins and Luke Delaney supported the operation by assisting with spacesuit procedures, monitoring the spacewalkers and operating the Canadarm2 robotic arm.
The four astronauts subsequently held a conference with ground-based engineers to discuss the operation and provide feedback for future spacewalk preparations.
Other Expedition 75 crew members continued research and maintenance activities in the Russian segment of the station.
Roscosmos flight engineer Sergey Teteryatnikov conducted cardiovascular and respiratory measurements. His activities included blood-pressure measurements and treadmill exercise while attached to sensors monitoring heart and breathing rates.
Flight engineer Anna Kikina serviced ventilation systems and scientific payload hardware, while station commander Pyotr Dubrov completed an overnight carbon dioxide monitoring session and inspected station modules and hatches.
Implications for future station operations
Completing the IROSA installation gives the ISS a larger electrical generation capability for the remaining period of its operational life.
The upgrade is relevant beyond routine research because the station must continue supporting its crew, visiting spacecraft, scientific payloads and critical environmental systems while NASA prepares for its eventual retirement.
The arrays also demonstrate how modular upgrades can extend the usefulness of complex orbital infrastructure. Rather than replacing the entire power system, NASA has supplemented existing equipment through a series of targeted installations requiring extensive robotic and extravehicular operations.
For the broader space industry, the project provides an operational example of maintaining and upgrading large structures in orbit. Such work requires coordinated spacecraft operations, robotic systems, spacesuit technology and ground-based engineering support.
Nevertheless, completing the eight installations does not mean that the station’s entire electrical infrastructure has been replaced or that all future maintenance requirements have been eliminated.
NASA’s November 6 update confirms that the installation work is complete. It does not provide a separate assessment of long-term array performance or a revised station operating lifetime.
The immediate result is a completed power augmentation program and an ISS electrical generation capacity reported at approximately 215 kilowatts, giving the orbital laboratory additional power resources for its ongoing research and operations.
