Roll Out Solar Array

The Roll Out Solar Array (ROSA) and its larger version ISS Roll Out Solar Array (iROSA) are lightweight, flexible power sources for spacecraft designed and developed by Redwire.[1]

This new type of solar array provides much more energy than traditional solar arrays at much less mass.[2] Traditional solar panels used to power satellites are bulky, with heavy panels folded together using mechanical hinges. Given a space-bound payload is limited in its mass and volume by necessity, ROSA is 20 percent lighter (with a mass of 325 kg)[3] and one-fourth the volume of rigid panel arrays with the same performance.[4]

ROSA is a flexible and rollable solar array that operates the same way a measuring tape unwinds on its spool. 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. Both the sides of the wing have a narrow arm that extends through the length of the wing to provide support to the array, called a high strain composite boom. The booms look like split tubes made of a stiff composite material, flattened and rolled up lengthwise. The array does not need any motor to unfurl. This is achieved using the potential energy stored in the booms that is released as each boom transitions from a coil shape to a straight support arm. The solar wings are then deployed due to strain energy in rolled booms that are present at the two ends of the structure.

Patent

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.[5] They received a patent for this work on April 1, 2014.[5]

History on ISS

Applications

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. This is especially noticeable with the first arrays to launch, with the P6 and P4 Trusses in 2000 and 2006.

To augment the wings, three pairs of scaled-up versions known as iROSA launched in the trunks of the SpaceX Dragon 2 cargo version from early June 2021 to early June 2023, aboard SpaceX CRS-22, CRS-26, and CRS-28.[23] A fourth pair will be launched after 2025.[24][22] These arrays, half the width of the existing wings, are intended to be deployed along the central part of the wings between half and two-thirds of their length, and their planes are canted at a 10° angle above the plane of the existing solar array wings.[25]

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

Missions

CRS-11

See also

• Solar panels
• Solar array
• Electrical system of the International Space Station
• Redwire

External links

• Deployment of experimental solar array on ISS
• Jettisoning of solar array from the ISS
• Deployment of operational solar array on ISS, June 25, 2021