WASHINGTON — After completing an upgrade to the International Space Station’s power system in June, NASA is moving ahead with plans so as to add two more solar arrays to the station.
Boeing and Redwire announced June 28 that they signed a contract for a fourth pair of ISS Roll-Out Solar Arrays, or IROSA, for the station. Redwire developed the array technology, often known as ROSA, which uses solar arrays which might be launched in a rolled-up form factor after which extend once in space.
The businesses had previously partnered on six IROSA arrays installed on the station starting in 2021. The third, and originally final, pair of IROSA arrays arrived on the station in early June on a SpaceX cargo Dragon spacecraft. NASA astronauts Steve Bowen and Woody Hoburg installed them on two spacewalks June 9 and 15.
The brand new arrays are designed to enhance the station’s original solar arrays, which have degraded through the years. The IROSA are installed on top of arrays, partially shadowing them but providing a net increase in power. Each array generates greater than 20 kilowatts of power.
“The power to enhance that power is absolutely necessary for us,” said Dina Contella, NASA ISS operations integration manager, during a June 1 briefing to preview those spacewalks. “The power to bring our power as much as normal levels and even slightly higher for future research is absolutely critical for the space station.”
At that briefing, she said there was interest in installing a fourth IROSA pair. “We do have plans in place to try to construct a fourth set of arrays, funding notwithstanding.”
In a June 30 statement, NASA spokesperson Josh Finch said NASA and Boeing, the ISS prime contractor, “have a plan in place” for the fourth IROSA pair. Those arrays can be delivered to the station in late 2025 or early 2026. He said the contract modification for the brand new arrays was valued at slightly greater than $35 million.
Redwire didn’t disclose the worth of its contract with Boeing to supply the arrays. It saw the award as a validation of its overall ROSA technology, which was also used on NASA’s Double Asteroid Redirection Test planetary defense spacecraft and might be incorporated on the Power and Propulsion Element for the lunar Gateway.
“We’re happy with the successful deployment of six IROSAs on the ISS up to now, making it the gold standard for large-scale power generation with proven flight heritage,” said Peter Cannito, chief executive of Redwire, in an announcement.
“The six IROSAs installed on the ISS are modern examples to support further utilization with technologies and systems that weren’t envisioned when the ISS was designed and built,” said John Mulholland, Boeing vice chairman and program manager for the ISS, within the statement.