Nonlinear Dynamic Equations of Satellite Relative Motion  Around an Oblate Earth

Xu, Guangyan; Wang, Danwei

doi:10.2514/1.33616

“…Therefore, based on the desired crosstrack velocity, the argument of latitude at which the burn must occur can be calculated based on Eq. (22). In this scenario, the first burn should occur immediately and the following burns should occur at the argument of latitude which produces the desired crosstrack motion.…”

Section: Initial Burnmentioning

confidence: 99%

Swarm-Keeping Strategies for Spacecraft Under J2 and Atmospheric Drag Perturbations

Morgan

¹

,

Chung²,

Blackmore

³

et al. 2012

Journal of Guidance, Control, and Dynamics

View full text Add to dashboard Cite

This paper presents several new open-loop guidance methods for spacecraft swarms composed of hundreds to thousands of agents with each spacecraft having modest capabilities. These methods have three main goals: preventing relative drift of the swarm, preventing collisions within the swarm, and minimizing the propellant used throughout the mission. The development of these methods progresses by eliminating drift using the Hill-Clohessy-Wiltshire equations, removing drift due to nonlinearity, and minimizing the J2 drift. In order to verify these guidance methods, a new dynamic model for the relative motion of spacecraft is developed. These dynamics include the two main disturbances for spacecraft in Low Earth Orbit (LEO), J2 and atmospheric drag. Using this dynamic model, numerical simulations are provided at each step to show the effectiveness of each method and to see where improvements can be made. The main result is a set of initial conditions for each spacecraft in the swarm which provides the trajectories for hundreds of collision-free orbits in the presence of J2. Finally, a multi-burn strategy is developed in order to provide hundreds of collision-free orbits under the influence of atmospheric drag. This last method works by enforcing the initial conditions multiple times throughout the mission thereby providing collision-free trajectories for the duration of the mission.

show abstract

“…Therefore, the time of the burn, or θ 0 , can be chosen, so that Eq. (22) are not violated and a circular projection is still achieved. In this example it is likely that the burn will be non-equatorial.…”

Section: A Effects Of Crosstrack Motionmentioning

confidence: 99%

Swarm Keeping Strategies for Spacecraft under J2 and Atmospheric Drag Perturbations

Morgan

¹

,

Chung

²

,

Blackmore

³

et al. 2011

AIAA Guidance, Navigation, and Control Conference

View full text Add to dashboard Cite

This paper presents several new open-loop guidance methods for spacecraft swarms composed of hundreds to thousands of agents with each spacecraft having modest capabilities. These methods have three main goals: preventing relative drift of the swarm, preventing collisions within the swarm, and minimizing the propellant used throughout the mission. The development of these methods progresses by eliminating drift using the Hill-Clohessy-Wiltshire equations, removing drift due to nonlinearity, and minimizing the J2 drift. In order to verify these guidance methods, a new dynamic model for the relative motion of spacecraft is developed. These dynamics include the two main disturbances for spacecraft in Low Earth Orbit (LEO), J2 and atmospheric drag. Using this dynamic model, numerical simulations are provided at each step to show the effectiveness of each method and to see where improvements can be made. The main result is a set of initial conditions for each spacecraft in the swarm which provides the trajectories for hundreds of collision-free orbits in the presence of J2. Finally, a multi-burn strategy is developed in order to provide hundreds of collision-free orbits under the influence of atmospheric drag. This last method works by enforcing the initial conditions multiple times throughout the mission thereby providing collision-free trajectories for the duration of the mission.

show abstract

“…The Hill-Clohessy-Wiltshire (HCW) equation cannot be used for high-fidelity modeling and simulation due to its assumptions on linearization, circular orbit, and no perturbation. The high-fidelity nonlinear dynamic models for the reference (chief) and relative motions with both the J 2 perturbation and atmospheric drag were presented by either hybrid states [19] or the classical orbital parameters [21], based on [22]. We present some key attributes of swarm dynamics based on these new models.…”

Section: A Swarm Orbital Dynamics Under J 2 and Atmospheric Dragmentioning

confidence: 99%

On Development of 100-Gram-Class Spacecraft for Swarm Applications

Hadaegh

¹

,

Chung

²

,

Manohara

³

2016

IEEE Systems Journal

View full text Add to dashboard Cite

Abstract-A novel space system architecture is proposed that would enable 100-gram-class spacecraft to be flown as swarms (100s to 1000s) in low Earth orbit (LEO). Swarms of Silicon Wafer Integrated Femtosatellites (SWIFT) present a paradigmshifting approach to distributed spacecraft development, missions, and applications. Potential applications of SWIFT swarms include sparse aperture arrays and distributed sensor networks. New swarm array configurations are introduced and shown to achieve the effective sparse aperture driven from optical performance metrics. A system cost analysis based on this comparison justifies deploying a large number of femtosatellites for sparse aperture applications. Moreover, this paper discusses promising guidance, control, and navigation methods for swarms of femtosatellites equipped with modest sensing and control capabilities.

show abstract

Nonlinear Dynamic Equations of Satellite Relative Motion Around an Oblate Earth

Cited by 85 publications

References 5 publications

Swarm-Keeping Strategies for Spacecraft Under J2 and Atmospheric Drag Perturbations

Swarm-Keeping Strategies for Spacecraft Under J2 and Atmospheric Drag Perturbations

Swarm Keeping Strategies for Spacecraft under J2 and Atmospheric Drag Perturbations

On Development of 100-Gram-Class Spacecraft for Swarm Applications

Contact Info

Product

Resources

About