Probability of Collision with Tethered Spacecraft

TL;DR

This paper presents a new method for estimating collision probability of tethered spacecraft that accounts for tether shape and configuration uncertainty, providing more accurate risk assessments during close encounters.

Contribution

It introduces a novel approach that maximizes collision probability over all feasible tether configurations, improving risk estimation accuracy for tethered spacecraft.

Findings

More realistic collision risk estimates for tethered spacecraft.

Enhanced ability to distinguish hazardous from benign encounters.

Application to real-world conjunction events demonstrates effectiveness.

Abstract

This Engineering Note addresses the challenge of estimating the probability of collision for tethered spacecraft during close encounters with other space objects. Standard probability of collision methods, based on spherical hard-body assumptions, tend to be overly conservative when applied to long tether systems. We introduce a method that accounts for the tether's spatial extent and configuration uncertainty by maximizing the probability of collision over all physically admissible tether shapes. Applied to real-world conjunction events involving a kilometer-scale flexible inextensible tether, the method yields more realistic risk estimates. This approach improves the ability to distinguish hazardous from benign encounters, thereby supporting more informed collision avoidance decisions.