Cow-culation: Reentry Impact Risk to Livestock in the Satellite Megaconstellation Era

TL;DR

This paper assesses the risk of livestock in New Zealand being hit by reentering satellite debris, estimating a 0.3-1% chance of cow casualties over five years due to megaconstellation satellite reentries.

Contribution

It introduces a novel analysis of space debris reentry impact risk on livestock, combining satellite casualty models with bovine density data in NZ.

Findings

Estimated 0.3-1% chance of cow casualties in NZ from satellite reentries over 5 years.

Highlights potential risks of satellite megaconstellations to terrestrial livestock.

Provides a preliminary risk assessment using existing datasets and models.

Abstract

The commercial space industry is launching more satellites into Low Earth Orbit every year. Aotearoa New Zealand (NZ) has a thriving dairy and cattle industry. Unfortunately, these industries could come into (high speed) cow-llision, as the rapid launch rate and short operational lifetimes of satellites in megaconstellations like Starlink result in a high reentry rate at NZ's latitudes. This could intersect with NZ's famously large population of livestock. We predict this will be an udder disaster for any cows that are hit, as they are squishy and moo-ve much more slowly than space debris. Using a global bovine density dataset, previously published satellite casualty probability code, and a complete lack of funding to do this calculation carefully enough for submission to a peer-reviewed journal, we calculate a $\simeq 0.3-1% chance of a cow-sualty in NZ from reentering Starlink Gen2 debris over the next 5 years.