![An iROSA being unrolled after its installation was completed in June 2023. Six were initially built by Redwire. Boeing has contracted with the company for two additional arrays. Credit: NASA](https://www.spaceflightinsider.com/wp-content/uploads/2023/06/Fyrk5ITWABAMB_D.jpg)
An iROSA being unrolled after its installation was accomplished in June 2023. Six were initially built by Redwire. Boeing has contracted with the corporate for 2 additional arrays. Credit: NASA
Redwire Corporation announced it was awarded a contract from Boeing to develop two additional solar arrays for the International Space Station.
During the last two years, the ISS has received six Roll-Out Solar Arrays (iROSAs), all built by Redwire under contract from Boeing, to reinforce the aging station’s existing power-generating capability. It’s now set to get two more as early as 2025, in keeping with NASA.
“The six iROSAs installed on the ISS are progressive examples to support further utilization with technologies and systems that weren’t envisioned when the ISS was designed and built,” said John Mulholland, Boeing’s vice chairman and program manager for the ISS, in a June 28, 2023, statement. “It’s a tribute to the performance of the design, construct, and operational teams that NASA has contracted for 2 additional arrays to finish the upgrade to the complete eight-array set.”
Delivered in pairs on three SpaceX cargo Dragon missions in June 2021, November 2022 and most recently in June 2023, each was installed over six of the eight existing legacy arrays.
The legacy arrays are 112 feet long and 39 feet wide (24 meters long and 12 meters wide). They were delivered to the station in pairs during 4 space shuttle missions in 2000, 2006, 2007 and 2009, each with an estimated lifespan of about 15 years.
Since then, the solar cells on those massive array wings have degraded, as expected, and are usually not as efficient as they once were. The brand new iROSAs are designed to reinforce the present arrays by being installed at an angle excessive of the legacy units.
![The location of the initial six iROSA devices that were installed on the ISS. Credit: NASA](https://www.spaceflightinsider.com/wp-content/uploads/2020/07/iRosa_future-e1611770958964.jpg)
The placement of the initial six iROSA devices that were installed on the ISS. Credit: NASA
While they shade a few of the older arrays’ solar cells, the brand new arrays are far more efficient. Each is 60 feet long by 20 feet wide (18.2 meters long by 6 meters wide) once fully unrolled and might generate greater than 20 kilowatts of power.
With six already installed, they produce greater than 120 kilowatts of power. Combined with the legacy arrays, the station’s current capability is about 250 kilowatts, in keeping with NASA, which is roughly what the combined legacy arrays were originally capable of manufacturing in direct sunlight.
A fourth set of iROSAs would go over the remaining two legacy arrays and make sure the ISS has enough power through its planned end of life around 2030.
“We’re pleased with the successful deployment of six iROSAs on the ISS so far, making it the gold standard for large-scale power generation with proven flight heritage,” said Peter Cannito, Redwire chairman and CEO, in a press release. “The continuation of this system with the award of an extra two iROSAs, bringing the entire to eight arrays, is a testament to the excellence and dedication of our team and the coordination amongst our suppliers and partners.”
The technology behind iROSA was first tested via a technology demonstrator called ROSA, which was tested on the station in 2017.
Since then, the ROSA technology has been used on NASA’s Double Asteroid Redirection Test spacecraft. A much larger version is anticipated for use for the Power and Propulsion Element of NASA’s Lunar Gateway outpost, set to launch as early as 2025.
Furthermore, a retractable version of the ROSA technology is anticipated for use for Astrobotic’s Lunar Vertical Solar Array program, which the corporate plans to make use of to enable mobile power sources on the Moon’s south pole for NASA Artemis missions.
“We’re proud to be supporting Astrobotic with our groundbreaking ROSA technology for his or her VSAT program,” said Adam Biskner, executive vice chairman of Redwire, in a March 1, 2023, news release. “With this latest application of ROSA technology, Redwire is constant to supply next generation lunar infrastructure solutions for critical lunar activities, which is able to enable latest scientific discovery, long-term operations, and humanity’s everlasting presence on the Moon.”