Low-thrust tour of the main belt asteroids

Abstract

This work presents some preliminary results on the low-thrust tour of the main asteroid belt. The asteroids are visited through a series of fly-by's that minimise the total cost of the manoeuvres. The sequence of asteroids to visit and the initial orbit for the spacecraft are chosen based on the Minimum Orbit Intersection Distance (MOID) between the orbit of the asteroids and the orbit of the spacecraft. The transfers between asteroids are designed using a low-thrust analytical model that provides nearly optimal solutions with coast and thrust arcs. The mission analysis is completed with a study of the transfer of the spacecraft from the Earth to the first orbit of the tour. Number of revolutions on the intermediate phasing orbit

A 2-D Trajectory Design Algorithm for Multiple Asteroid Flyby Missions

“…The first building block concerns the use of asteroids reference data (time, t ref , and position, M ref ) in order to determine the transit positions on the ecliptic plane. It can be easily seen that the condition of transit is expressed in terms of the related true anomaly tr by considering the reference frame transformation from perifocal to the heliocentric-ecliptic: with and imposing: with 𝜈 (1) tr < 𝜈 (2) tr . Two values of true anomaly result from this equation, each of them related to the position and velocity vectors, (1) tr , (2) tr and (1) tr , (2) tr , found by solving an initial value problem, the Direct Kepler's Problem (DKP).…”

“…It can be easily seen that the condition of transit is expressed in terms of the related true anomaly tr by considering the reference frame transformation from perifocal to the heliocentric-ecliptic: with and imposing: with 𝜈 (1) tr < 𝜈 (2) tr . Two values of true anomaly result from this equation, each of them related to the position and velocity vectors, (1) tr , (2) tr and (1) tr , (2) tr , found by solving an initial value problem, the Direct Kepler's Problem (DKP). It can be seen that the most of asteroids pass through the…”

“…1), so to require the formulation of a dedicated method for the resolution of the optimization problem about the selection of targets. In our study, it is explicitly assumed that our prospector spacecraft is propelled by chemical rockets, contrary to several recent works in the literature, where a similar asteroid tour problem is studied for low-thrust propelled spacecraft, either electrical [2,3], or solar-sailing [4]. Moreover, this type of optimization problem is often solved by heuristic genetic algorithms [5] that allow to evaluate a set of initial solutions, and, introducing "disorder" elements, are able to create new solutions following an evolutionary path.…”

Multiple near-earth asteroid rendezvous mission: Solar-sailing options

“…To date, several studies have been carried out on multiple-object missions, mainly considering spacecraft propelled by electric thrusters. In the majority of the cases, the problem is divided into two sub-problems: firstly, potential sequences of encounters are found and, therefore, an optimisation strategy is used to refine and validate the sequences chosen among the ones found (Bertrand et al, 2009, Di Carlo andVasile, 2016). Usually, the first sub-problem is the most challenging one due to the very large number of potential sequences to test.…”

“…A second approach is to use a heuristic optimisation algorithm such as the ant-colony optimiser (Ceriotti and Vasile, 2010, Stuart et al, 2016a, Stuart et al, 2016b or an algorithm inspired by the behaviour of an amoeboid organism, the Physarum polycephalum (Di Carlo et al, 2017, Vasile et al, 2015. In any case, because of the large amount of trajectories to be computed, simplified trajectory models are used which require little computational effort (for instance, an approach using impulsive Lambert arcs is the one considered in Di Carlo and Vasile (2016)). Despite several studies have been found in the literature about multiple-object missions, very few of them deal with solar sails, such as the ENEAS+ mission study (Dachwald and Seboldt, 2005) and the DLR/ESA Gossamer roadmap technology reference study (Dachwald et al, 2014).…”