Automatic trajectory planning for low-thrust active removal mission in low-earth orbit

Abstract

In this paper two strategies are proposed to de-orbit up to 10 noncooperative objects per year from the region within 800 and 1400 km altitude in Low Earth Orbit (LEO). The underlying idea is to use a single servicing spacecraft to de-orbit several objects applying two different approaches. The first strategy is analogous to the Traveling Salesman Problem: the servicing spacecraft rendezvous with multiple objects in order to physically attach a de-orbiting kit that reduces the perigee of the orbit. The second strategy is analogous to the Vehicle Routing Problem: the servicing spacecraft rendezvous and docks with an object, spirals it down to a lower altitude orbit, undocks, and then spirals up to the next target.In order to maximise the number of de-orbited objects with minimum propellant consumption, an optimal sequence of targets is identified using a bio-inspired incremental automatic planning and scheduling discrete optimisation algorithm. The optimisation of the resulting sequence is realised using a direct transcription method based on an asymptotic analytical solution of the perturbed Keplerian motion. The analytical model takes into account the perturbations deriving from the J 2 gravitational effect and the atmospheric drag.

CAMELOT: Computational-Analytical Multi-fidElity Low-thrust Optimisation Toolbox

“…AIDMAP has been extensively tested on a variety of Travelling Salesman and Vehicle Routing problems, providing good results [7,19,27].…”

“…The change of the right ascension, when performing a transfer between two satellites, is realised by changing the semimajor axis of the servicing spacecraft and taking advantage of the dependence on the altitude of the natural rate of nodal regression due to J 2 [25]. Smaller inclination orbits are more favorable for adjustment of the right ascension realised by changing the semimajor axis [7]; therefore, the group of object with lower possible inclination is selected.…”

“…Here, a multiple asteroid fly-by mission and a multiple active debris removal mission are presented. These two scenarios were developed within two mission studies published by the authors in [6] and [7].…”

“…Using these formulas, both osculating and averaged analytical propagations can be realised. FABLE includes perturbations due to zonal harmonics J 2 , J 3 , J 4 , J 5 , atmospheric drag (with an exponential atmospheric density model [7]), solar radiation pressure, third-body gravitational perturbation, and low-thrust propulsion. FABLE can also take into account eclipses using a cylindrical model for the Earth's shadow.…”

“…a Low-thrust propulsion only. b Low-thrust propulsion and gravity assistwith the Earth Section greater than 1 are found [7]. The potential 721 target objects are then further selected based on two main criteria: the rate of the drift of the right ascension of the ascending node due to the second zonal harmonic of the gravity, J 2 , and the Criticality of Spacecraft Index (CSI) [28].…”