SpaceX darkens Starlink satellites. Others, however, also want to build megakon constellations

Every few weeks, another pack of sixty satellites of the Starlink constellation built by SpaceX gets into Earth's orbit. Astronomers are working intensively with company representatives to reduce the impact of satellites on astronomical observations. The problem is that SpaceX is not the only company that intends to send thousands of satellites into orbit.

The scientific community learned about the problem that may arise from entire megacon constellations in May 2019, when the first batch of SpaceX satellites belonging to SpaceX was launched into orbit. The satellites observed over the following days, like a chain of bright lights, were visible in the night sky by many people around the world. On the other hand, astronomers watched with horror as satellites flying over their telescopes ruined valuable observational data.

SpaceX works with astronomers

Nevertheless, both sides approached the problems constructively and the American Astronomical Society began working with SpaceX to develop techniques to mitigate the influence of satellites on astronomical observations from Earth.

In January this year, SpaceX launched an experimental DarkSat satellite, whose surface was darkened to reduce the amount of light it reflects. The problem, however, is that the less light the satellite reflects, the more energy it will have to retain, and this leads to serious problems with heat dissipation and keeping the instruments of the satellite at a sufficiently low temperature. During the last launch a few days ago, one of the satellites was equipped with a sun visor that will block solar radiation before it reaches the surface of the satellite. The effectiveness of this solution can only be tested in a few weeks when VisorSat reaches its target orbit. Despite this, however, the astronomical environment is a little more optimistic about the situation, due to the fact that SpaceX has become so involved in the search for a solution to the problem of bright satellites.

Not just SpaceX

The problem, however, is that the Starlink megaconstruction, which will consist of several, if not tens of thousands of satellites, is not the only, but only the first constellation of this type. Meanwhile, so far, talks about providing a dark sky with nobody else's satellite operators.

OneWeb is one of the companies that also planned to send dozens of satellites into orbit. Talks with her ended, however, one phone call, because a few months ago the company declared bankruptcy. Other operators of future constellations are not interested in talking with astronomers yet.

Meanwhile, new proposals are emerging. Even OneWeb, despite filing for bankruptcy, submitted a few weeks ago plans to extend the originally assumed constellation by another ... 48,000 satellites that would ensure that the company would meet the rapidly growing demand for internet bandwidth.

The situation has just got worse, 'says Pat Seitzer of the University of Michigan, who studied the impact of Starlininks and other satellite constellations on astronomy. Such plans include adding another 50,000 satellites to the currently planned 60,000, which are expected to be in orbit. This is really a serious problem.

According to OneWeb's proposal, the satellites would be in orbit at an altitude of 1200 km, which is slightly more than twice as high as the satellites of the constellation Starlink (550 km). Here, however, it should be noted that in a higher orbit the satellites will be visible longer after sunset and before sunrise. In this way, in one of the analyzed scenarios, the Very Rubin Observatory being built in Chile would have more than 500 satellites in view at any time during the night.

Of course, satellites located 1200 km above the Earth will no longer be visible to the naked eye, but the sensitive telescope instruments will still be blinded by the reflected light, which will significantly hinder, if not prevent valuable scientific observations.

Are satellites a problem for observatories?

The American Astronomical Society has conducted talks with 23 observatories around the world, trying to find out what impact the built or planned satellites of the satellite will have on them, starting with the initial set of 1584 Starlink satellites.

Most observatories have stated that 1584 satellites will be a huge challenge for astronomers and that the observatories themselves will face serious financial problems. Observatories conducting surveys all over the sky will have particular problems, in which satellites passing through the field of view cannot be avoided.

If there are 20,000 satellites belonging to different megastonets in orbit , they will have a significant impact on essentially all astronomical observations, and for half of the observatories it will mean the end of existence.

Therefore, at the end of June, AAS is organizing an online workshop where the situation will be discussed with astronomers and companies planning to build a satellite constellation. Among the participants, in addition to representatives of SpaceX, there will also be representatives of Amazon, which plans to build the Kuiper megastoneline.

We hope that, just like SpaceX, all other companies will make appropriate efforts to minimize the negative impact of satellites on Earth's research. Otherwise, we will be completely deprived of access to the real night sky, which allows us to explore the secrets of the universe, both near and distant - adds Lowenthal.

SpaceX darkens Starlink satellites. Others, however, also want to build megaconestations