Hop Reachable Domain on Irregularly Shaped Asteroids

Wen, Tongge; Zeng, Xia; Circi, Christian; Gao, Yang

doi:10.2514/1.g004682

Cited by 88 publications

(11 citation statements)

References 29 publications

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“…The polyhedron gravitational model [29][30][31], and the finite element method [32] have been widely used in studying the surrounding particle dynamics around irregular asteroids. Nevertheless, when investigating the rubble-pile structure deformation of asteroids, the discrete element method (DEM) is usually adopted to deal with the interaction of the granular systems [33].…”

Section: Methodsmentioning

confidence: 99%

The Coupling Orbit–Attitude–Structure Evolution of Rubble-Pile Asteroid with Earth Flyby in the Restricted Three-Body Problem

et al. 2022

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Some asteroids flying close to Earth may pose a threat of impact. Among them, the structural and dynamical characteristics of rubble-pile asteroids can be changed because of the tidal force of the Earth in this process. This can provide key information for predicting the dynamical evolution of potentially hazardous asteroids. In this study, the long-term evolution of the coupling orbit–attitude–structure of these small bodies is presented numerically based on the integration of two models. One is the 3D discrete element method, which models the structure and irregular shape of the rubble-pile asteroid. The other is the dynamical model of the circular restricted three-body problem (CRTBP). This provides a more precise dynamical environment of the asteroid orbital deflection, morphological modification, and attitude angles analysis compared to the frequently adopted two-body problem. Parametric studies on the asteroid evolution were performed focusing on its flyby distance and the bulk porosity. Numerical results indicate that the Earth flyby can form different patterns of modification of asteroids, where the rubble-pile structure can be destructed by considering the bulk porosity. The asteroid orbital deflection and attitude variational trends are also summarized based on the simulations of multi-orbital revolutions.

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Section: Methodsmentioning

confidence: 99%

The Coupling Orbit–Attitude–Structure Evolution of Rubble-Pile Asteroid with Earth Flyby in the Restricted Three-Body Problem

et al. 2022

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“…With a large enough velocity increment, the surface hopping rover will lift off and switch to orbital motion. 21) Afterward, several collisions between the rover and the asteroid surface will happen unless the initial velocity increment exceeds the asteroid's escape velocity directly. During this process, if the rover bounces after the collision, its motion still belongs to the orbital motion (or ballistic motion).…”

Section: Dynamical Modelsmentioning

confidence: 99%

Hopping Trajectory Planning for Asteroid Surface Exploration Accounting for Terrain Roughness

Zeng

Wang

2021

Trans. Japan Soc. Aero. S Sci.

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Hopping rovers have become a promising way of asteroid surface exploration. This paper focuses on the hopping trajectory design between two given surface points and discusses the irregular terrain's influence on the design process. By taking the hopping rover as a point mass, dynamical equations are derived based on the polyhedral method. The principle of hopping trajectory planning is summarized with the related solving algorithm. The initial velocity increments required to control the subsequent hopping trajectories are determined based on parabolic motion. The numerical simulations apply a triaxial ellipsoid to approximate comet 133P/Elst-Pizarro preliminarily. The smooth and rocky polyhedron models of the ellipsoid are constructed, respectively. With the two models, the different initial conditions' hopping trajectories are planned and compared to verify the proposed planning method and discuss the influence of terrain roughness on the trajectory design.

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“…( 2), and gravitation contained in the potential force in Eq. ( 3) are calculated in a closed form by assuming the asteroid as a homogeneous polyhedron [23,24,25]. Gravitation derived by polyhedron, whose calculation error only originates from the error of polyhedron shape model of an asteroid, could guarantee the accuracy whether the field point is in the exterior or interior, or on the surface of the shape model.…”

Section: Global Construction Of the Surface Dynamical Environmentmentioning

confidence: 99%

Long-term Trends of Regolith Movement on the Surface of Small Bodies

Huang¹,

Yu²,

Cheng³

et al. 2021

Preprint

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This paper studies the long-term migration of disturbed regolith materials on the surface of Solar System small bodies from the viewpoint of nonlinear dynamics. We propose an approximation model for secular mass movement, which combines the complex topography and irregular gravitational field. Choosing asteroid 101955 Bennu as a representative, the global change of the dynamical environment is examined, which presents a division of the creeping-slidingshedding regions for a spun-up asteroid. In the creeping region, the dynamical equation of disturbed regolith grains is established based on the assumption of "trigger-slide" motion mode. The equilibrium points, local manifolds and largescale trajectories of the system are calculated to clarify the dynamical characteristics of long-term regolith movement. Generally, we find for a low spin rate, the surface regolith grains flow toward the middle latitudes from the polar/equatorial regions, which is dominated by the gradient of the geopotential. While spun up to a high rate, regolith grains tend to migrate toward the equator, which happens in parallel with a topological shift of the local equilibria at low latitudes. From a long-term perspective, we find the equilibrium points dominate the global trends of regolith movements. Using the methodology developed in this paper, we give a prospect or retrospect to the secular motion of regolith materials during the spin-up process, and the results reveal a significant regulatory role of the equilibria. Through a detailed look at the dynamical scheme under different spin rates, we achieve a macro forecast of the global trends of regolith motion during the spin-up process, which explains the global geologic evo-

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Hop Reachable Domain on Irregularly Shaped Asteroids

Cited by 88 publications

References 29 publications

The Coupling Orbit–Attitude–Structure Evolution of Rubble-Pile Asteroid with Earth Flyby in the Restricted Three-Body Problem

The Coupling Orbit–Attitude–Structure Evolution of Rubble-Pile Asteroid with Earth Flyby in the Restricted Three-Body Problem

Hopping Trajectory Planning for Asteroid Surface Exploration Accounting for Terrain Roughness

Long-term Trends of Regolith Movement on the Surface of Small Bodies

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