An analysis tool for collision avoidance manoeuvres using aerodynamic drag

TL;DR

This paper presents a new analysis tool that evaluates the effectiveness of aerodynamic drag-based collision avoidance maneuvers for Low Earth Orbit satellites, considering current space weather and parameter uncertainties.

Contribution

It introduces an analytical tool to assess aerodynamic collision avoidance strategies, accounting for environmental data and operational constraints, with application to a university satellite.

Findings

Aerodynamic maneuvers can effectively increase in-track separation.

Parameter uncertainties influence the collision probability assessment.

Evasive strategies can be derived for satellites without thrusting capabilities.

Abstract

Aerodynamic collision avoidance manoeuvres provide an opportunity for satellites in Low Earth Orbits to reduce the risk during close encounters. With rising numbers of satellites and objects in orbit, satellites experience close encounters more frequently. Especially those satellites without thrusting capabilities face the problem of not being able to performimpulsive evasive manoeuvres. For satellites in Low Earth Orbits, though, perturbing forces due to aerodynamic drag may be used to influence their trajectories, thus offering a possibility to avoid collisions. This work introduces a tool for the analysis of aerodynamic collision avoidance manoeuvres. Current space-weather data are employed to estimate the density the satellite encounters. Achievable in-track separation distances following a variation of the ballistic coefficient through a change in attitude are then derived by evaluating an analytical equation from literature. Considering additional constraints for the attitude, e.g., charging phases, and uncertainties in the used parameters, the influence of a manoeuvre on the conjunction geometry and the collision probability is examined. The university satellite Flying Laptop of the University of Stuttgart is used as an exemplary satellite for analysis, which show the general effectiveness of evasive manoeuvres employing aerodynamic drag. First manoeuvring strategies can be deducted and the influence of parameter uncertainties is assessed.