Analysis of collision avoidance manoeuvres using aerodynamic drag for the Flying Laptop satellite

TL;DR

This paper investigates the feasibility of using aerodynamic drag to perform collision avoidance maneuvers for the Flying Laptop satellite in Low Earth Orbit, demonstrating potential for propellant-free collision mitigation.

Contribution

It introduces a method to utilize aerodynamic drag for collision avoidance in satellites without thrusters, validated through analysis and flight data comparison.

Findings

Aerodynamic analysis shows feasible collision avoidance for Flying Laptop.

Variation in ballistic coefficient can achieve significant in-track separation.

Method applicable to similar satellites in lower orbits with variable ballistic coefficients.

Abstract

Collision avoidance is a topic of growing importance for any satellite orbiting Earth. Especially those satellites without thrusting capabilities face the problem of not being able to perform impulsive collision avoidance manoeuvres. For satellites in Low Earth Orbits, though, perturbing accelerations due to aerodynamic drag may be used to influence their trajectories, thus offering a possibility to avoid collisions without consuming propellant. Here, this manoeuvring option is investigated for the satellite Flying Laptop of the University of Stuttgart, which orbits the Earth at approximately 600 km. In a first step, the satellite is aerodynamically analysed making use of the tool ADBSat. By employing an analytic equation from literature, in-track separation distances can then be derived following a variation of the ballistic coefficient through a change in attitude. A further examination of the achievable separation distances proves the feasibility of aerodynamic collision avoidance manoeuvres for the Flying Laptop for moderate and high solar and geomagnetic activity. The predicted separation distances are further compared to flight data, where the principle effect of the manoeuvre on the satellite trajectory becomes visible. The results suggest an applicability of collision avoidance manoeuvres for all satellites in comparable and especially in lower orbits than the Flying Laptop, which are able to vary their ballistic coefficient.