Starlink satellites surprisingly fall from the sky – SWR knowledge

Establishing Internet connections with the help of huge satellite networks in space – that is the goal of several companies. The best known is probably SpaceX, which started launching rocket after rocket into space in 2019, ultimately stationing up to 42,000 satellites there. Regions of the world that are poorly supplied by cable should be able to get fast broadband internet in this way.

Every few weeks, a SpaceX rocket launches up to 60 Starlink satellites into space in one fell swoop. 2,000 are already there, but SpaceX was unlucky with the latest batch of satellites launched on February 3: Why are the Starlinks falling out of the sky in rows instead of swinging into orbit?

Solar storm knocked satellites out of orbit

Space travel in low earth orbit has a powerful and unpredictable adversary that peaks every 11 years on average: the sun. It was a solar storm that caused 40 of the 49 launched satellites of the Starlink network to burn up again in the earth’s atmosphere just a few hours after launch. Not good news for Elon Musk and his company Space X, which is just building this network.

Remnants of the earth’s atmosphere at an altitude of 200 kilometers

But it was foreseeable that something like this could happen. After the start, the Starlinks initially move in a rather low orbit at a little more than 200 kilometers altitude. At this altitude, remnants of the earth’s atmosphere are still present. Everything that flies there rubs against these remains of the atmosphere and therefore slows down over time and sinks.

Sun’s eruption sends magnetic field bubble

Of course, SpaceX also knows this and therefore normally brings its satellites to higher altitudes quickly after the separation from the rocket. But this time the sun was a little faster. An eruption at the sun’s surface sent a magnetic field bubble along with masses of particles toward Earth. This solar storm hit the Earth’s atmosphere, heating it up and causing the Earth’s atmosphere to expand into space even further than usual.

Starlink satellites burned up in Earth’s atmosphere

For the Starlinks, the universe must have suddenly felt very tough as more and more gas atoms penetrated from the deeper earth’s atmosphere to an altitude of 200 kilometers. Satellite operators are familiar with this phenomenon and in such cases quickly raise the orbits again by firing engines to compensate for the friction losses. But the Starlink satellites couldn’t do it anymore, crashed and burned up in the earth’s atmosphere.

Friction effect important for disposal of defective satellites

Despite this incident, SpaceX will not increase the altitude at which the Starlink satellites will be launched. You actually want to use the friction effect for waste disposal. Because it can happen that among the assembled satellites of the Starlink network there are also non-functional ones. They should then, with full intention, quickly dive back into the earth’s atmosphere and burn up there.

The satellites will only be placed in higher and final orbits after the first functional tests have been passed. Space X will have to brace for more storm events in space – solar activity fluctuates in an 11-year cycle and the sun’s most active phase in the new cycle is yet to begin.