Roll Out Solar Array

The new solar array design rolls up to form a compact cylinder for launch with significantly less mass and volume, potentially offering substantial cost savings as well as an increase in power for satellites.

ROSA has a center wing made of a flexible material which support the strings of photovoltaic cells that produce electricity.

The solar wings are then deployed due to strain energy in rolled booms that are present at the two ends of the structure.

Brian R. Spence and Stephen F. White were the first persons to patent the idea of the Roll Out Solar Array on January 21, 2010.

[3] Over the weekend of June 17–18, 2017, engineers on the ground remotely operated the International Space Station's robotic Canadarm2 to extract the Roll Out Solar Array (ROSA) experiment from the SpaceX Dragon resupply ship.

Engineers observed the behavior of the solar array as it was exposed to extreme temperature swings through the ISS's orbit.

[8] In June 2021, two new solar iROSA panels were installed on the International Space Station's P6 truss mast cans.

[10][11][12][13] The new arrays were intended to give the station a total of 120 kilowatts of additional augmented power during daytime orbit.

[14][needs update] On 3 December 2022, Expedition 68 crew members Josh Cassada and Frank Rubio installed an iROSA at Array 3A on the S4 truss segment and connected it to the US power system.

[21][22] The final set of iROSAs, the seventh and eighth, are planned to be sent to the ISS for augmenting the 2A and 3B power channels on the P4 and S6 truss segments in 2025.

[23] Over time, the photovoltaic cells on the ISS' existing Solar Array Wings on the Integrated Truss Structure have degraded gradually, having been designed for a 15-year service life.

[25][14] Work to install iROSA's support brackets on the P6 truss mast cans holding the Solar Array Wings was initiated by the crew members of Expedition 64 in late February 2021.

[26][14] After the first pair of arrays were delivered in early June,[12] a spacewalk on 16 June by members Shane Kimbrough and Thomas Pesquet of Expedition 65 to place one iROSA array on the 2B power channel and mast can of the P6 truss[27] was successful until a spacesuit computer malfunctioned and the iROSA encountered technical problems with deployment, resulting in the spacewalk being cut short early, having lasted 7 hours and 15 minutes.

Astronauts Akihiko Hoshide and Mark Vande Hei of Expedition 65 were slated to carry out the preceding bracket installation on 24 August 2021.