arXiv subjects

Luke Peterson

Publications and source records attributed to Luke Peterson.

3 recordsLinked to original sources

arXiv2026

Cislunar Pursuit-Evasion Game on Periodic and Quasi-Periodic Orbits

Cislunar spacecraft operate in nonlinear and unstable environments that make defensive maneuver planning difficult. We formulate cislunar spacecraft pursuit and evasion as a zero-sum differential game in the circular restricted three-body problem. Each spacecraft controls its thrust and reference orbit phase, enabling motion along periodic orbits and across quasi-periodic tori while remaining near the reference. We solve the game using a constrained discrete-time differential dynamic programming method that enforces hard input constraints. We propose a shared time regularization to synchronize both spacecraft while refining the discretization near close lunar passages. Numerical results on periodic and quasi-periodic orbits show that phase control improves maneuvering flexibility while limiting departure from the reference orbit. The discrete-time method also provides a large computational advantage over a continuous-time formulation. Comparisons between quasi-halo and quasi-near-rectilinear halo orbits show that close lunar passages create larger escape opportunities but also increase the sensitivity of the encounter. These results show that reference orbit geometry is an important part of defensive cislunar mission design.

eess.SY↗

arXiv2023

Machine Learning-Based Multi-Objective Design Exploration Of Flexible Disc Elements

Design exploration is an important step in the engineering design process. This involves the search for design/s that meet the specified design criteria and accomplishes the predefined objective/s. In recent years, machine learning-based approaches have been widely used in engineering design problems. This paper showcases Artificial Neural Network (ANN) architecture applied to an engineering design problem to explore and identify improved design solutions. The case problem of this study is the design of flexible disc elements used in disc couplings. We are required to improve the design of the disc elements by lowering the mass and stress without lowering the torque transmission and misalignment capability. To accomplish this objective, we employ ANN coupled with genetic algorithm in the design exploration step to identify designs that meet the specified criteria (torque and misalignment) while having minimum mass and stress. The results are comparable to the optimized results obtained from the traditional response surface method. This can have huge advantage when we are evaluating conceptual designs against multiple conflicting requirements.

cs.NE↗

arXiv2019

O2- and CO-Rich Atmospheres for Potentially Habitable Environments on TRAPPIST-1 Planets

Small exoplanets of nearby M dwarf stars present the possibility to find and characterize habitable worlds within the next decade. TRAPPIST-1, an ultracool M dwarf star, was recently found to have seven Earth-sized planets of predominantly rocky composition. The planets e, f, and g can have a liquid water ocean on their surface given appropriate atmospheres of N2 and CO2. Particularly, climate models have shown that the planets e and f can sustain a global liquid water ocean, for >=0.2 bar CO2 plus 1 bar N2, or >=2 bars CO2, respectively. These atmospheres are irradiated by ultraviolet emission from the star's moderately active chromosphere, and the consequence of this irradiation is unknown. Here we show that chemical reactions driven by the irradiation can produce and maintain more than 0.2 bar O2 and 0.05 bar CO if the CO2 is >=0.1 bar. The abundance of O2 and CO can rise to more than 1 bar under certain boundary conditions. Because of this O2-CO runaway, habitable environments on the TRAPPIST-1 planets entail an O2- and CO-rich atmosphere with coexisting O3. The only process that would prevent the runaway is direct recombination of O2 and CO in the ocean, a reaction that is facilitated biologically. Our results indicate that O2, O3, and CO should be considered together with CO2 as the primary molecules in the search for atmospheric signatures from temperate and rocky planets of TRAPPIST-1 and other M dwarf stars.

astro-ph.EP↗