SpaceX satellite is too bright to interfere with astronomy?

Private companies such as Amazon, Google, and SpaceX are advancing into the space business, but while technological regulations have not been met, there are many things that may be of concern, such as the space waste issue. One of them is that the problem that the satellites launched by SpaceX are too bright will be a threat to research into the world’s astronomy and space, and is suffering from a solution.

Space development company SpaceX launched 60 satellites on May 27, 2019 as part of the Starlink project, which builds a huge communication network by launching satellites. Although the launch was successful, the satellite’s light was so bright that numerous scientists later pointed out that it could influence scientific research. As a result, SpaceX conducted an experiment with black coating on one of 60 new satellites launched on January 6, 2020.

According to SpaceX, the reason why the satellite shines brightly is possible due to several factors. Starlink is emitted from a low position in the space atmosphere orbit, and the brightness increases due to reflection when the satellite group deploys each solar panel. And when it reaches the operating orbit at an altitude of 550 km, the grade is about 5, and the brightness is visible with the naked eye. It is also pointed out that a telescope’s capture range is related to the speed at which it crosses the satellite, and that the slower the speed, the more luminance is.

Discussions in the astronomy community are being made about the effects of satellites on the telescope and how to solve them. University of Michigan astronomer Petrick Seiza points out that the satellite constellation is likely to be brighter than 99% of the matter in Earth’s orbit. According to calculations, it is dawn and dusk that have the greatest effect on the brightness of Starlink. Therefore, asteroids close to Earth that need to be observed at dawn are expected to have a great influence on the investigation.

The LSST (Large Synoptic Survey Telescope), which will be installed in Chile, will be extensively filming the entire sky every three days for 10 years after 2022, but this could be greatly affected. The research team said they are working on a software fix that predicts the satellite’s orbit and removes the electric light, but it is difficult to get rid of them all, and concerns remain about system errors. If the location of the satellite is known in advance, the satellite may take a picture without the satellite by taking a picture of the time zone or other location, but this becomes impossible as the number of satellites increases. SpaceX will finally launch more than 4,000 satellites.

For this reason, an attempt was made to coat one satellite launched on January 6th. The blackened satellite is DarkSat to suppress light confusion reflections. Darksat has already been in Earth’s orbit, but its operation is after late February and it will take some time to see its effectiveness. Also, there is no law yet to regulate the brightness of satellites. In addition to applying black the aircraft, SpaceX says it can also adjust its launch trajectory as needed. Related information can be found here .