The power of constellations in times of crisis

Updated: Apr 20

The rapid response of Elon Musk's SpaceX to the Ukraine crisis using its vast constellation of Starlink satellites is an inspiring example of what responsive space can do.


The ongoing war in Ukraine has proven to be a stark reminder of the importance of infrastructure in times of crisis. Soon after entering Ukraine, Russia targeted some of the country's most important infrastructure using a mix of cyberattacks and bombing of physical assets - including the country's telecommunications network.


However, Ukraine has largely been able to remain connected due to the surprising resilience of its software infrastructure and relentless efforts by citizens to repair physical assets and maintain the availability of internet service. [1]


Another key actor in Ukraine's ability to remain connected has been the timely help provided by Elon Musk's vast Starlink constellation. Thousands of terminals have been shipped off to many of the country's cities, and citizens report a generally excellent quality of service. Recent reports even suggest Ukraine's military is using Starlink to carry out drone strikes on Russian tanks. [2]


A number of Starlink satellites and their coverage of Kyiv modeled in the live instance Sedaro Satellite

Location Matters

The surprising scale of the Russian operation in Ukraine has many experts concerned about the possible proliferation of similar actions by nuclear-armed countries. Many in Taiwan are closely monitoring the situation in Ukraine and drawing ideas on how to defend against a possible Chinese invasion. [3] China's deep understanding of telecommunication networks could mean that, in the event of an invasion, Taiwan might have to rely on satellite internet to a great degree.


Starlink satellites mostly orbit at latitudes below 53 degrees, which cover most of the world's biggest population centers. At latitudes below but close to 53 degrees, the many orbital planes of the Starlink constellation are tightly packed, resulting in a higher probability of more than one satellite being over a given geographical area. As it happens, the latitude at which Kyiv is located features some of the highest density of Starlink flyovers, allowing for near-uninterrupted coverage.


Countries like Taiwan, however, experience some of the lowest Starlink flyover densities, as they are located near the equator. But by how much does this density really vary? Using Sedaro Satellite, we can estimate this change by modeling the Starlink constellation and calculating coverage over any location on the globe.


Simulating Starlink's Coverage

Sedaro Satellite's efficient cloud-architecture is ideal for simulating large satellite constellations and effortlessly analyzing the performance of the entire constellation. Using a simple Python script, we automated the parallel simulation of a representative sample of Starlink satellites. Each satellite was evaluated against a single condition: coverage of a particular location on the Earth's surface.


Coverage of Kyiv over 8 hours of a single Starlink satellite's orbit shown in Sedaro Satellite

As expected, over an 8-hour period, each satellite only covers Kyiv for a small amount of time. However, with a set of only 200 evenly distributed Starlink satellites, we can ensure that Kyiv goes no more than 25 minutes without seeing a satellite. This coverage, however, is significantly reduced for Taipei, where the constellation set exhibits a gap of over 45 minutes.


In reality of course, the gaps are significantly smaller, but the percent difference between the two location remains an important consideration. For now, we'll continue to watch the growth of responsive satellite constellations with awe.


Sedaro Satellite

Check out our live beta instance of Sedaro Satellite. Simulate complex satellite missions and spacecraft subsystems in minutes.


Sources

[1] https://www.washingtonpost.com/technology/2022/03/29/ukraine-internet-faq/

[2] https://www.dw.com/en/ukraine-is-using-elon-musks-starlink-for-drone-strikes/a-61270528

[3] https://www.nytimes.com/2022/03/01/world/asia/ukraine-taiwan-china-russia.html

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