# 7th International Conference on Astrodynamics Tools and Techniques (ICATT)

6-9 November 2018
DLR Oberpfaffenhofen, Germany
Europe/Amsterdam timezone

## SOLAR-SAIL TRANSFERS FROM INVARIANT OBJECTS TO L5 PERIODIC ORBITS

9 Nov 2018, 09:30
30m
103 and 105 combined

### 103 and 105 combined

Building 135
Oral presentation at the conference 03: Low Thrust

### Speaker

Alvaro Fernandez Mora (TU Delft Aerospace Engineering)

### Description

The continuing development of solar-sail technology in combination with the rising interest in a mission to the Sun-Earth $L_5$ point for heliophysics and the search for Trojan asteroids, raises the question of using solar sailing as the primary propulsion method to enable such a mission. This paper therefore investigates a range of solar-sail transfers to the $L_5$ point, departing from different invariant objects in the neighbourhood of Earth: natural and solar-sail displaced equilibrium points, families of periodic orbits and their associated stable invariant manifolds. Also the arrival conditions are varied to be either natural or solar-sail displaced periodic orbits around the $L_5$ point. The transfers are obtained using a hybridisation of different trajectory design techniques. First, a multi-objective genetic algorithm is applied to obtain near-feasible initial guesses, which are transformed into feasible transfers using a differential correction method. Through a continuation on the fixed time of flight, the differential corrector is subsequently used to reduce the transfer time. As the differential corrector implements a stepwise constant control of the solar-sail attitude, a pseudospectral optimisation method is finally taken at hand to obtain a smooth, continuous control profile, to, if possible, further reduce the transfer time. This approach results in fast solar-sail transfers of 396 to 1194 days, depending on the departure and arrival configuration and the assumed solar-sail technology. These results can serve as preliminary design solutions for a mission to the Sun-Earth $L_5$ point.

Please find an extended abstract in the attached pdf-file

### Primary author

Alvaro Fernandez Mora (TU Delft Aerospace Engineering)

### Co-authors

Jeannette Heiligers (Delft University of Technology) Mr Andrew Heaton (NASA Marshall Space Flight Center, Huntsville, Alabama)