Connecting the Equinoctial Elements and Rodrigues Parameters: A New Set of Elements

Peterson, Joseph T. A.; Arya, Vishala; Junkins, John L.

doi:10.2514/1.g007347

Cited by 2 publications

(1 citation statement)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Similar very-low-altitude lunar orbits may represent interesting options for the deployment of constellations, provided that coordinated control of the orbit elements is feasible. In this study, orbital motion is described in terms of modified equinoctial elements, which are nonsingular in most operational scenarios [21]. All relevant perturbations are included in the dynamical model, i.e., several harmonics of the selenopotential and third body gravitational attraction due to the Sun and the Earth, whose orbital motion is described in an ephemeris model.…”

Section: Introductionmentioning

confidence: 99%

Low-Thrust Nonlinear Orbit Control for Very Low Lunar Orbits

Leonardi,

Pontani,

Carletta

et al. 2024

Applied Sciences

View full text Add to dashboard Cite

In the next decades, both space agencies and private competitors are targeting the lunar environment as a scientific and technological resource for future space missions. In particular, the confirmed existence of water-ice deposits in the vicinity of the poles (predominantly the south pole) makes polar or near-polar low lunar orbits attractive for the purpose of designing space missions that could search for suitable Lunar base sites. However, traveling very-low-altitude orbits is very challenging, as they are strongly perturbed by the Moon’s gravity field as well as third- and fourth-body effects due to the Earth and the Sun. Several studies demonstrate that these orbits are expected to impact the lunar surface in a few months. Therefore, the definition and implementation of an effective station-keeping strategy represents a crucial issue in order to extend satellites’ lifetime. In this paper, a feedback nonlinear control law is employed in order to perform corrective maneuvers aimed at keeping the state of the satellite within acceptable margins. The satellite is assumed to be equipped with a steerable and throttleable low-thrust propulsion system. The control law is based on the Lyapunov stability theory and does not require any reference path to track, with a considerable decrease in the computational cost. The proposed real-time control law includes control saturation, related to the maximum available thrust magnitude, and is developed employing modified equinoctial elements, in order to avoid singularities and extend its range of application. Finally, the strategy at hand is tested in the presence of all the relevant perturbations (i.e., harmonics of the selenopotential, third- and fourth-body effects) in order to show its effectiveness and efficiency.

show abstract

Section: Introductionmentioning

confidence: 99%

Low-Thrust Nonlinear Orbit Control for Very Low Lunar Orbits

Leonardi,

Pontani,

Carletta

et al. 2024

Applied Sciences

View full text Add to dashboard Cite

show abstract

Nonlinear Orbit Acquisition and Maintenance of a Lunar Navigation Constellation Using Low-Thrust Propulsion

Leonardi,

De Angelis,

Pontani

2024

Aerospace

View full text Add to dashboard Cite

In this research, a feedback nonlinear control law was designed and tested to perform acquisition and station-keeping maneuvers for a lunar navigation constellation. Each satellite flies an Elliptical Lunar Frozen Orbit (ELFO) and is equipped with a steerable and throttleable low-thrust propulsion system. Lyapunov stability theory was employed to design a real-time feedback control law, capable of tracking all orbital elements (including the true anomaly), expressed in terms of modified equinoctial elements (MEEs). Unlike previous research, control synthesis was developed in the complete nonlinear dynamical model, and allows for driving the spacecraft toward a time-varying desired state, which includes correct phasing. Orbit propagation was performed in a high-fidelity framework, which incorporated several relevant harmonics of the selenopotential, as well as third-body effects due to the gravitational pull of the Earth and Sun. The control strategy at hand was successfully tested through two Monte Carlo campaigns in the presence of nonnominal flight conditions related to estimation errors of orbit perturbations, accompanied by the temporary unavailability and misalignment of the propulsive thrust.

show abstract

Connecting the Equinoctial Elements and Rodrigues Parameters: A New Set of Elements

Cited by 2 publications

References 15 publications

Low-Thrust Nonlinear Orbit Control for Very Low Lunar Orbits

Low-Thrust Nonlinear Orbit Control for Very Low Lunar Orbits

Nonlinear Orbit Acquisition and Maintenance of a Lunar Navigation Constellation Using Low-Thrust Propulsion

Contact Info

Product

Resources

About