NASA has boosted the ISS’s solar power with lightweight roll-out arrays that unfurl like a mat, adding capacity for station operations and hundreds of experiments.
From its orbit roughly 250 miles above Earth, the International Space Station depends on the Sun as its primary energy source. Electricity from solar panels keeps life-support equipment running, powers astronauts’ day-to-day work, and enables hundreds of experiments aimed at improving life on Earth while also laying groundwork for future deep-space missions.
Over the last five years, NASA has been steadily strengthening the station’s ability to generate and route electrical power by adding a new generation of hardware known as International Space Station Roll Out Solar Arrays, or IROSAs. The approach builds on a technology demonstration conducted on the station in 2017, which evaluated how well the roll-out design would perform in the space environment.
Unlike the station’s original rigid solar panels, the new arrays are built to be light and compact at launch. They ride to orbit packed into a cylindrical shape and, once installed, deploy by unrolling—often likened to a yoga mat spreading out. This architecture is designed to cut both mass and volume in the rocket payload, helping maximize what can be delivered to the station. NASA also notes that the system uses an autonomous, self-deploying mechanism intended to reduce operational risk during the deployment process. The design can be scaled as needed for different mission requirements.
Even though each IROSA is about half the size of the station’s older “legacy” arrays, the upgrade is substantial. The newer units are capable of supplying about 28 kilowatts of additional power, expanding the station’s available electrical margin for onboard systems and science.
The installation campaign began in earnest in the early 2020s. Six of the roll-out arrays were mounted externally on the station between 2021 and 2023. Then, in 2023, updated power forecasts led to a request for an additional set. That extra pair launched to orbit stowed in the trunk of a SpaceX Dragon spacecraft as part of SpaceX’s 35th Commercial Resupply Services mission to the space station for NASA.
With eight IROSAs in place, NASA projects the station’s overall power increase will exceed 160 kilowatts, supporting both research and station operations. The agency frames the upgrade not only as a way to extend and strengthen the ISS’s work in low Earth orbit, but also as a step toward maturing technologies that will be needed farther from Earth.
In NASA’s view, the space station remains a critical proving ground—supporting projects that range from planetary defense efforts such as the Double Asteroid Redirection Test (DART) to preparations for future human exploration beyond Earth’s orbit.
Why it matters
More electrical power on the ISS translates directly into more capacity for experiments and greater flexibility for station operations, benefiting researchers, space agencies, and commercial partners that rely on the lab in orbit. The roll-out array design also demonstrates hardware concepts—compact, scalable, and lower-risk to deploy—that could be valuable for future spacecraft and deep-space missions. What to watch next is how the upgraded power margin is allocated: whether it enables new high-demand research, supports additional commercial activity, or informs solar power designs for missions beyond low Earth orbit.