I am trying to calculate and speculate the specifications of Starlink satellites (mainly related to propulsion) based on the accident on the 3rd of February 2022. There are multiple sources that describe the event and make simulations of the atmospheric perturbations at that time. Links here, here and here.

In summary, due to a CME, a magnetic storm (intensity G1 - modest) formed at an unexpected time, which increased thermospheric density and temperature. This had an effect on the Starlink satellites that were orbiting at 210km altitude at the time, waiting to be raised to ~340 km in the Low-Earth Orbit (LEO). The satellites experienced an increased atmospheric drag and eventually re-entered the atmosphere on 7 February. From the sources:

The heating raised the thermospheric temperature, and caused the thermosphere to expand, resulting in high mass density at a fixed altitude, such as 210 km. News-1 reported that onboard GPS position information suggested the escalation speed and severity of the storm caused atmospheric drag to increase up to 50% higher than during previous launches. The Starlink team commanded the satellites into a safe-mode where they were oriented so as to minimize drag—to effectively “take cover from the storm.

Now, how can I use this information to infer Starlink specs? We know that orbital drag could not be overcome by the thrusters when it increased by 50%. How can I include this in my calculations for thrust?

Also, the drag force experienced by the satellite is proportional to the mass density of the thermosphere. But, different models and simulations give different results. Example from this paper.

Model simulations driven by solar wind show that the first geomagnetic storm induced around 20% atmospheric density perturbations at 210 km altitude on 3rd February. The unexpected subsequent storm on 4th February led to a density enhancement of around 20%–30% at around 210 km. The resulting atmospheric drag can be even larger, since the regional density enhancement was over 60% and the satellite orbits were continuously decaying.

What would be a good approach here?



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