Astronauts have completed the installation of a new roll-out solar panel on the International Space Station on a spacewalk. The existing panels are more than twenty years old and will be upgraded. There will be a total of six new panels.
The new roll-out solar panels are placed in front of the old ones. Those old panels still work, but are beginning to show degradation after more than twenty years of use. The panels were designed for fifteen years of use.
In total, the ISS will receive six new iROSA panels. That stands for ISS Roll-Out Solar Array. The first panel has now been placed and taken into use. A second panel will be installed this week and the remaining four panels will be added in the coming years. The first two panels arrived at the ISS earlier this month with a Dragon cargo capsule from SpaceX.
The new panels are each 18.2 long and 6 meters wide, making them considerably smaller than the original panels, measuring 34.1 by 11.9 metres. The iROSA panels are mounted on the same arms as the current panels and partially cover them. According to NASA, each iROSA panel is good for a capacity of ‘more than 20 kilowatts’, while the current much larger panels are good for 17 to 23 kilowatts each.
When all six panels are installed, the total available power grows to a maximum of 215 kilowatts. With the old panels that is 160 kilowatts. Both systems remain in use, but the old panels are therefore partly covered by the new ones.
NASA will also use the deployable solar panels for other projects, such as the Lunar Gateway. In 2017, NASA already conducted tests with such ROSA panels on the space station ISS. The iROSA solar panels are a larger variant of this. Because the solar panels can be rolled up, it is easier to transport them to space. Once in use, the panels remain unrolled.
2017 video of a rollout solar panel experiment on the ISS.
The ISS will have six iROSA solar panels, on top of the existing eight panels.