Received: 14 February 2017 Revised: 15 August 2017 Accepted: 19 November 2017
No-guess indirect optimization of asteroid mission using
State Key Laboratory of Astronautic
Dynamics, Xi'an Satellite Control Center,
710043 Xi'an, China
Hong-Xin Shen, Department of Mechanics
and Engineering Science, College of
Engineering, Peking University, 100871
Beijing, China; or State Key Laboratory of
Astronautic Dynamics, Xi'an Satellite
Control Center, Xi'an 710043, China.
National Natural Science Foundation of
China, Grant/Award Number: 11702330
This paper researches the optimal opportunities and trajectories for an
asteroid-Earth return mission and compares different options in terms of time
length and reentry velocity. High specific impulse and steering capabilities of
solar electric propulsion are exploited to perform deep space maneuvers. An
indirect method based on the theory of optimal control is applied to find the tra-
jectory that maximizes the final mass. The boundary value problem that arises
from the application of the optimal control theory is solved by means of a shoot-
ing procedure based on Newton's method. In particular, the best opportunities to
reach the Earth are first analyzed by searching a time-free transfer that intercepts
the Earth's orbit at the most favorable point; suitable launch windows are then
determined. This technique shows significant benefit to define the initial solu-
tion that is required to start the optimization process so that no initial guess of
adjoints is required for the optimization. Mission opportunities returning from
asteroid Bennu (101955) are presented.
asteroid mission, indirect method, optimal control, trajectory optimization
Electric propulsion is considered one of the most promising options for future exploration of the solar system. The higher
specific impulse provided by Hall or ion thrusters, compared to chemical propulsion, reduces the propellant requirements
and increases the payload. Solar electric propulsion (SEP) has grown steadily worldwide and is, at present, a mature
technology that has been proven to be capable of performing interplanetary trajectories such as application to Deep
Hayabusa asteroid sample return mission,
and SMART-1 mission to the moon.
Therefore, the use of SEP for
the heliocentric part of an asteroid sample return trajectory seems to be advisable.
An indirect method is proposed to analyze low-thrust asteroid return trajectories using SEP. It is well known that many
local optima exist for an orbit transfer depending on the number of revolutions around the Sun and the contribution of
this paper is in the strategy that is adopted to find the best opportunities. In addition, in the present analysis, a trip-time
constraint is enforced to highlight the dependence of the performance index on the trip time. The final mass is expected to
be maximized. Direct entry is the most suitable option for the sample return to the Earth's surface,
and the optimization
procedure, in fact, concerns here only the direct return missions. Moreover, since direct entry is selected, only low values
of reentry velocity are permitted.
Thus, an additional constraint on the hyperbolic excess velocity at Earth arrival is
imposed when required.
Optim Control Appl Meth. 2018;39:1061–1070. wileyonlinelibrary.com/journal/oca Copyright © 2018 John Wiley & Sons, Ltd. 1061