Elon Musk, the chief executive of SpaceX, has given more details about plans to limit sunlight reflections from the Starlink satellites. The company will try to do this, among other things, by applying a kind of sun visors.
During a briefing, Elon Musk gave more information about what he calls VisorSat. This is a concept for a system that is integrated on the satellites and unfolds screens to prevent sunlight from falling on the reflective antennas. This is done by means of radio-transparent foam. According to Musk, it can be regarded as sun visors like those above the windscreen of cars. It must have a “huge effect” on the brightness of the satellites, Space News writes based on Musk’s statements.
The plan is to test VisorSat during the next Starlink launch. If SpaceX sticks to its current schedule, its upcoming launch is likely to take place sometime in May. Musk did not say how many of the satellites will be equipped with this concept. Typically, sixty Starlink internet satellites are launched into space per launch.
There is a second attempt to contain the brightness. After launch, it takes a while for the satellites to reach the desired, higher orbits around the Earth. During that phase, according to Musk, the satellites are relatively brighter due to the orientation of the solar panels, which is different than during the period when they are in their operational orbits around the earth. The alignment of the solar panels in relation to the earth will be adjusted so that less sunlight is reflected to the earth. According to Musk, this will lead to the satellites being a lot less visible from Earth during their ‘rise phase’.
The current satellites would already be a bit darker than the first series, which was launched in May 2019. Early this year, SpaceX also launched a satellite called Darksat with a special anti-reflective coating. These efforts are SpaceX’s response to ongoing criticism from astronomers. They have expressed concern about the excessive brightness of Starlink satellites, which could disrupt astronomical observations from Earth. It can lead to difficult-to-remove artifacts in images from terrestrial telescopes.