## Session

Poster Session 2

## Abstract

As expansion of deep space missions continue, Mars is quickly becoming the planet of primary focus for science and exploratory satellite systems. Due to the cost of sending large satellites equipped with enough fuel to last the entire lifespan of a mission, inexpensive small satellites equipped with low thrust propulsion are of continuing interest. In this paper, a model is constructed for use in simulating the control of a small satellite system, equipped with low-thrust propulsion in orbit around Mars. The model takes into consideration the fuel consumption and can be used to predict the lifespan of the satellite based on fuel usage due to the natural perturbation of the orbit. This model of the natural perturbations around Mars implements a Lyapunov Based control law using a set of gains for the orbital elements calculated by obtaining the ratio of the instantaneous rate of change of the element over the maximum rate of change over the current orbit. The thrust model simulates the control of the semi-major axis, eccentricity, and inclination based upon a thrust vector fixed to a local vertical local horizontal reference frame of the satellite. This allows for a more efficient fuel usage over the long continuous thrust burns by prioritizing orbital elements in the control when they have a higher relative rate of change rather than the Lyapunov control prioritizing the element with the greatest magnitude rate of change.

Control of Long-Term Low-Thrust Small Satellites Orbiting Mars

As expansion of deep space missions continue, Mars is quickly becoming the planet of primary focus for science and exploratory satellite systems. Due to the cost of sending large satellites equipped with enough fuel to last the entire lifespan of a mission, inexpensive small satellites equipped with low thrust propulsion are of continuing interest. In this paper, a model is constructed for use in simulating the control of a small satellite system, equipped with low-thrust propulsion in orbit around Mars. The model takes into consideration the fuel consumption and can be used to predict the lifespan of the satellite based on fuel usage due to the natural perturbation of the orbit. This model of the natural perturbations around Mars implements a Lyapunov Based control law using a set of gains for the orbital elements calculated by obtaining the ratio of the instantaneous rate of change of the element over the maximum rate of change over the current orbit. The thrust model simulates the control of the semi-major axis, eccentricity, and inclination based upon a thrust vector fixed to a local vertical local horizontal reference frame of the satellite. This allows for a more efficient fuel usage over the long continuous thrust burns by prioritizing orbital elements in the control when they have a higher relative rate of change rather than the Lyapunov control prioritizing the element with the greatest magnitude rate of change.