Over time, the photovoltaic cells on the wings 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 wing, from 2021 to 2022, NASA will launch six scaled-up versions of the Roll Out Solar Array aboard three SpaceX Dragon 2 cargo missions, SpaceX CRS-22, CRS-23, and CRS-24. These arrays are more lightweight and generate more energy than the exisiting arrays. They are intended to be deployed along the central part of the wings up to two thirds of its length. Work to install the support brackets on the truss mast cans that hold the wings was initiated by the members of Expedition 64.