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Power Up: Roll Out Solar Arrays Boost Space Station Power Supply

From the International Space Station’s unique position 250 miles above Earth, the Sun is a vital source of energy. Solar power supports the station’s life support systems, daily activities, and hundreds of research investigations that improve life on Earth and prepare humans for deep space exploration. Over the past five years, NASA augmented the station’s power generation and distribution capability with next-generation International Space Station Roll Out Solar Arrays (IROSAs).

An International Space Station Roll Out Solar Array deploys in 2022.

NASA

In 2017, a technology demonstration conducted aboard the space station tested the effectiveness of the arrays. The lightweight, compact design launches as a cylinder and unfurls like a yoga mat after installation. This advanced design reduces mass and volume at launch and uses an autonomous, self-deploying system that minimizes risks during rollout.

Illuminated solar arrays and structural trusses of the International Space Station are shown against the darkness of space, with sunlight flaring near the center of the frame and Earth’s curved horizon visible below.

Sunlight flares across the International Space Station’s solar arrays.

NASA

The IROSAs were designed, manufactured, and tested by Redwire under a contract with Boeing and are about half the size of the station’s legacy arrays. Despite being smaller, the arrays are capable of producing about 28 kilowatts of additional power.

The first two International Space Station Roll Out Solar Arrays loaded in a SpaceX Dragon’s trunk before delivery to the orbiting laboratory during the company’s 22nd commercial resupply services mission for NASA in 2021.

SpaceX

Six IROSAs were installed outside of the space station between 2021 and 2023. In 2023, power projections prompted a request for another set of IROSAs, which launched in Dragon spacecraft’s trunk during the SpaceX 35th commercial resupply services mission to space station for NASA. Together, the eight IROSAs will increase power by more than 160kW for research and operations.

NASA astronauts perform a spacewalk to install an International Space Station Roll Out Solar Array with the assistance of the Canadarm2 robotic arm in 2022.

NASA

With the full upgrade in place, the space station’s revitalized power system not only supports NASA’s legacy in low Earth orbit but also helps advance technology that will extend the agency’s reach into the solar system. From planetary defense demonstrations, like the Double Asteroid Redirection Test, to future human exploration efforts, the space station is an essential testbed for the technologies needed for expeditions beyond Earth’s orbit.

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