A realistic, parametric compilation of optimised heliocentric solar sail trajectories

Hughes, Gareth Wynn (2005) A realistic, parametric compilation of optimised heliocentric solar sail trajectories. PhD thesis, University of Glasgow.

Abstract

In this thesis, a selection of numerical optimisation methods were developed for
application to realistic solar sail heliocentric trajectory optimisation problems. A
Non-Linear Programming method based on Sequential Quadratic Programming was
developed, with the sail controls parameterised in time. This method was hybridised
with Genetic Algorithms or locally-optimal analytical control laws to generate an
initial guess, where required. The goal of this thesis is to create a detailed catalogue
of trajectories to a broad range of heliocentric targets, subject to realistic constraints
on trip-time, sail performance, and thermal-limited solar approach. This thesis
illustrates the wide range of targets in the solar system that can be reached with solar
sailing. In addition, the trajectory problems for which solar sailing is not attractive
are also identified.
Trajectory analysis of sample return missions to the terrestrial planets, Mars,
Venus and Mercury, has been conducted. Extensive depmiure date scans were
perfOlmed, where it was found that there are minima and maxima in trip-time,
separated by discontinuities, providing effective launch windows. Roundtrip optimal
launch dates were identified, after combining outbound and return departure date
scans. For Mercury rendezvous, the application of positive launch excess velocity
and a Venus gravity assist was investigated, where a small trip-time saving can be
made.
Trajectories to rendezvous with the Short Period Comet Wirtanen have been
optimised, where it was found that a significant reduction in trip time and launch
mass could have been realised, relative to a conventional mission. An investigation
of using higher performance sails to flyby Long Period Comets has also been
conducted, to demonstrate that solar sailing could be used to reach newly discovered
comets soon after first discovery, such as the previous Hale-Bopp apparition. It is
also shown that solar sailing could be used, instead of solar electric propulsion, to
rendezvous with two Main-Belt asteroids, with a reduction in launch mass. The open ended nature of solar sailing was used to show that rendezvous with two further
asteroids is also possible. It is also shown that a three-phase trajectory concept,
utilising an inclination cranking manoeuvre, could be used to return a sample from a
high inclination Near-Earth Asteroid, that would be essentially impossible to reach
using conventional propulsion.
It is demonstrated that flyby missions to the outer planets, such as Pluto are
feasible in reasonable timescales using a solar photonic assist concept. However,
due to the faint solar radiation pressure at Jupiter, only flyby missions are practical to
the Jovian system with solar sails. An extensive trade-off between launch hyperbolic
excess energy, Jupiter arrival velocity, hip-time, and the number of photonic assist
loops has been conducted. By contrast, solar sailing appears to be the only feasible
option for missions to the Heliopause at 200 AD. Heliopause trajectory analysis
included investigation of the number of loops, and the effect of thermallyconstrained
closest solar approach on escape velocity and trip-time. It was found
that, in order to reach the Heliopause in 25 years, a solar sail of characteristic
acceleration of order 1.5 mm S-2 would be required, executing a thermally
constrained solar photonic assist at 0.25 AD. Investigation of the effect of positive
launch energy is also conducted for Heliopause trajectOlies.
A key near-term mission application for solar sails is a Solar Polar Orbiter.
Trajectory analysis has revealed that a solar sail transfer to a true solar polar orbit,
Earth resonant at 0.48 AU, in 5 years would require a characteristic acceleration of
0.42 nun S-2. In the course of the parametric analysis, two-phase and three-phase
scenarios were investigated, with an assessment of the effect of spiralling down to a
close cranking orbit radius from positive launch excess energy.
Finally, new transfers to exotic, displaced Non-Keplerian Orbits have been
optimised for a range of final orbit dimensions among one family of these unique
orbits. For lower performance sails, transfers to artificial Lagrange points have been optimised, in the context of the Geostorm and Polar Observer missions.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Subjects: T Technology > TL Motor vehicles. Aeronautics. Astronautics
• Colleges/Schools: College of Science and Engineering > School of Engineering > Autonomous Systems and Connectivity
• Supervisor's Name: McInnes, Prof. Colin R.
• Date of Award: 2005
• Depositing User: Ms Dawn Pike
• Unique ID: glathesis:2005-5007
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 07 Mar 2014 11:58
• Last Modified: 07 Mar 2014 11:58
• URI: https://theses.gla.ac.uk/id/eprint/5007