<p>A dynamical understanding of orbits in the Earth-Moon
neighborhood that can sustain long-term activities and trajectories that link
locations of interest forms a critical foundation for the creation of
infrastructure to support a lasting presence in this region of space. In response, this investigation aims to
identify and exploit fundamental dynamical motion in the vicinity of a
candidate ‘hub’ orbit, the L2 southern 9:2 lunar synodic resonant near
rectilinear halo orbit (NRHO), while incorporating realistic mission
constraints. The strategies developed in
this investigation are, however, not restricted to this particular orbit but
are, in fact, applicable to a wide variety of stable and nearly-stable cislunar
orbits. Since stable and nearly-stable
orbits that may lack useful manifold structures are of interest for long-term
activities in cislunar space due to low orbit maintenance costs, strategies to
alternatively initiate transfer design into and out of these orbits are
necessary. Additionally, it is crucial
to understand the complex behaviors in the neighborhood of any candidate hub
orbit. In this investigation, a
bifurcation analysis is used to identify periodic orbit families in close
proximity to the hub orbit that may possess members with favorable stability
properties, i.e., unstable orbits.
Stability properties are quantified using a metric defined as the stability
index. Broucke stability diagrams, a
tool in which the eigenvalues of the monodromy matrix are recast into two
simple parameters, are used to identify bifurcations along orbit families. Continuation algorithms, in combination with
a differential corrections scheme, are used to compute new families of periodic
orbits originating at bifurcations.
These families possess unstable members with associated invariant
manifolds that are indeed useful for trajectory design. Members of the families nearby the L2 NRHOs
are demonstrated to persist in a higher-fidelity ephemeris model. </p><p><br></p>
<p>Transfers based on the identified nearby dynamical
structures and their associated manifolds are designed. To formulate initial guesses for transfer
trajectories, a Poincaré mapping technique is used. Various sample trajectory designs are
produced in this investigation to demonstrate the wide applicability of the
design methodology. Initially, designs
are based in the circular restricted three-body problem, however, geometries
are demonstrated to persist in a higher-fidelity ephemeris model, as well. A strategy to avoid Earth and Moon eclipse
conditions along many-revolution quasi-periodic ephemeris orbits and transfer
trajectories is proposed in response to upcoming mission needs. Lunar synodic resonance, in combination with
careful epoch selection, produces a simple eclipse-avoidance technique. Additionally, an integral-type eclipse
avoidance path constraint is derived and incorporated into a differential
corrections scheme as well. Finally,
transfer trajectories in the circular restricted three-body problem and
higher-fidelity ephemeris model are optimized and the geometry is shown to
persist.</p>
| Identifer | oai:union.ndltd.org:purdue.edu/oai:figshare.com:article/14445717 |
| Date | 07 May 2021 |
| Creators | Emily MZ Spreen (10665798) |
| Source Sets | Purdue University |
| Detected Language | English |
| Type | Text, Thesis |
| Rights | In Copyright |
| Relation | https://figshare.com/articles/thesis/Trajectory_Design_and_Targeting_For_Applications_to_the_Exploration_Program_in_Cislunar_Space/14445717 |
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