Danny Owen

Danny Owen


Postgraduate Research Student

Academic and research departments

Astrodynamics, Surrey Space Centre.

About

My research project

Publications

CubeSat missions that take advantage of ride-sharing opportunities to the Moon are typically limited by a small v budget. In this paper, a patching point method is applied to design a low-energy lunar transfer for a spacecraft initially placed into a circumlunar free-return trajectory. Initial conditions generated within weak stability boundaries further guarantee ballistic lunar capture upon arrival. A large number of optimised trajectories are produced, with a minimum mission v cost of 32.51 m/s. Additionally, the B-plane values of the spacecraft during its initial flyby of the Moon are investigated. A relationship between the initial position of the Sun in the synodic frame and the B-plane values is observed, in which successful trajectories appear to favour entering into certain orbital resonances with the Moon.

The JUICE and Europa Clipper missions will soon be launched to investigate the presence of liquid subsurface oceans underneath the icy moons of Jupiter. Both missions rely on complex moon tour trajectories whose design can benefit from a preliminary understanding of the moons' relative geometry when candidate flyby sequences are researched. To aid with this objective, a new time-periodic system of equation of motion is introduced based on the 4:2:1 Laplace resonance of the Io-Europa-Ganymede system. The dynamical system is investigated with numerical continuation techniques that seek to grow equilibria and periodic orbits from the circular restricted three-body problem into periodic and quasi-periodic solutions that populate the phase space when fourth-and fifth-body perturbations are taken into account. The stability of these solutions is further analyzed in the new time-periodic model, searching for stable and unstable manifolds that can help identify fuel-efficient transfer opportunities between the Galilean moons of Jupiter.

Methods of generating heteroclinic connections between quasi-periodic orbits typically rely on human-in-the-loop or machine learning techniques to find intersections in sets of data in more than three dimensions. We propose a fully systematic method of generating these connections using an invariant property found in knot theory: the linking number. This method proves to be robust in detecting heteroclinic connections between isoenergetic invariant tori in the circular restricted three-body problem.