2 astronauts will finish upgrading ISS solar arrays during spacewalk today: Watch it live

Anil Menon and Joshua Kutryk are performing a spacewalk to install the eighth and final International Space Station Roll-Out Solar Array, or iROSA. The work matters because the new array completes a major upgrade to the station’s electrical power system. NASA scheduled the extravehicular activity for roughly seven hours on Nov. 5.

The astronauts are working outside the ISS, where they will attach and deploy the final solar array. This follows their Oct. 29 spacewalk, when they installed the seventh iROSA. That earlier excursion was the 100th U.S. spacewalk from the ISS and the first Canadian astronaut EVA since 2019.

The completed installation will help increase the station’s power-generating capacity from 160 kilowatts to about 215 kilowatts. The upgrade began in June 2021 and has taken more than five years to finish. NASA planned live coverage before the spacewalk began.

An International Space Station Roll-Out Solar Array, or iROSA, is a deployable solar-power unit attached to the outside of the station. It carries photovoltaic cells that turn sunlight into electrical energy. Its roll-out design allows a large collecting surface to be packed compactly for launch and then extended in orbit.

The arrays are installed beside the station’s existing solar arrays. Astronauts attach the hardware during spacewalks, connect it to the station’s power system, and deploy the flexible panel surface. The article does not describe these technical steps in detail, so the mechanism here comes from established spacecraft design knowledge.

The article reports that the eighth and final iROSA was scheduled for installation on Nov. 5. Together, the upgrade raises ISS power capacity from 160 kilowatts to about 215 kilowatts. That increase supports the station’s continuing operations and future electrical needs.

The ISS power system is being increased from 160 kilowatts to about 215 kilowatts. NASA describes that change as a boost of about 30 percent. More available electrical power gives the station a larger energy supply for its equipment, operations, and research activities.

The project uses eight International Space Station Roll-Out Solar Arrays. Menon and Kutryk were scheduled to install the eighth and final array during their Nov. 5 spacewalk. One week earlier, on Oct. 29, they installed the seventh iROSA. The arrays augment the station’s existing power-generating system.

The upgrade began in June 2021 and took more than five years to complete. The final installation marks the end of that process, according to NASA’s description. The article does not provide a separate figure for how much power each individual iROSA contributes, only the total change from 160 to about 215 kilowatts.

An extra 55 kilowatts of capacity, rising from 160 to about 215 kilowatts, gives the ISS more electrical headroom. That matters because a space station must continuously power life-support systems, computers, communications, experiments, lighting, and other equipment. The article highlights the larger generating capacity but does not name specific new activities.

The key mechanism is simple: the iROSAs collect sunlight and convert it into electricity. That electricity enters the station’s power system, where it can be distributed among operating systems and research hardware. Greater capacity can reduce competition among those demands and leave more room for additional equipment or experiments.

The upgrade is now reaching completion after starting in June 2021. Menon and Kutryk’s final installation brings the total to eight iROSAs. Any precise list of new ISS capabilities is not stated in the article, so the safe conclusion is that the station gains a larger electrical supply for present and future operations.

Completing the upgrade required more than five years because the work was carried out as a long, staged installation rather than a single task. NASA began the process in June 2021, and astronauts added the arrays over time. The final spacewalk on Nov. 5 was meant to install the eighth and last iROSA.

Each array requires work outside the station, so astronauts must perform spacewalks to position and connect the hardware. The article provides a clear example: Menon and Kutryk installed the seventh iROSA during their Oct. 29 EVA, then returned outside about a week later for the eighth. Their Nov. 5 spacewalk was scheduled to last roughly seven hours.

The article does not explain every scheduling, engineering, or operational constraint behind the five-plus-year timeline. It does establish that the upgrade involved eight arrays, multiple EVAs, and a gradual effort to raise power from 160 kilowatts to about 215 kilowatts.

Solar arrays must be exposed to sunlight, so their collecting surfaces need to sit outside the ISS rather than inside a pressurized module. Station walls, equipment, and windows would block or weaken the sunlight reaching an indoor panel. External placement also gives a roll-out array room to extend into open space.

Astronauts install the hardware outside because the array must be attached to the station’s structure and connected to its external power system. They can then deploy the panel surface away from the station. The article confirms that Menon and Kutryk are performing spacewalks to install the final iROSA, but it does not explain this engineering rationale.

This arrangement creates a demanding job. Astronauts must work in spacesuits while handling large equipment in orbit. The article says the final EVA was scheduled to last roughly seven hours. It also reports that eight iROSAs will complete the power upgrade, increasing capacity from 160 kilowatts to about 215 kilowatts.

Solar panels use photovoltaic cells to convert sunlight into electricity. When sunlight strikes a cell, its energy frees charged particles inside a semiconductor. The resulting movement of charge creates direct-current electricity. A spacecraft’s power system then manages and distributes that electricity to onboard equipment.

The ISS uses solar arrays positioned outside the station so they can receive sunlight in orbit. The arrays generate power whenever they are illuminated, while the station’s electrical system sends that power to its systems and experiments. The source article focuses on the iROSA installation and does not explain the photovoltaic process, so this description uses established science.

The upgraded ISS system will increase power-generating capacity from 160 kilowatts to about 215 kilowatts. NASA calls that an increase of about 30 percent. The eighth and final iROSA was scheduled for installation during Menon and Kutryk’s roughly seven-hour spacewalk on Nov. 5.