The term “homeland security”, seems to have become synonymous with terrorism in the minds of the general public. However, there are other threats to the security of the United States homeland that can be just as, if not more, devastating than terrorism. Included among these other threats is the potential of an asteroid collision with Earth. Historically, asteroid impact events have been responsible for the devastation of our planet and many of the mass extinction events encountered throughout the geologic record. Knowledge of physical parameters such as structure and rotational dynamics of the asteroid are critical parameters in developing interception and deflection techniques, as well as assessing the risk associated with these bodies and mitigation planning in the event of impact. This thesis encompasses the study of eight potentially hazardous asteroids identified in conjunction with NASA’s OSIRIS REX Mission and observed via the Target Asteroid Project, along with observations from the Robotically Controlled Telescope, and the Asteroid Light Curve Database of Photometry. Photometric data was extracted from all observations. Rotation periods of each target were confirmed using Lomb-Scargle time series analysis, with possible secondary periods indicated in the cases of Hathor (2.2169 hours), Bede (161.1501 hours), and Phaethon (4.5563 hours). Shape models for 2002 FG7, 2004 JN13, and Icarus were produced using light curve inversion techniques These are believed to be the first such models for these asteroids.

<div> Space operations from the dawn of the Space Age have resulted in a large, and growing, resident space object population. However, the availability of sensor resources is limited, which presents a challenge to Space Situational Awareness applications. When direct communication with an object is not possible, whether that is due to a lack of access for active satellites or due to the object being characterized as debris, the only independent information source for learning about the resident space object population comes from measurements. Optical measurements are often a cost-effective method for obtaining information about resident space objects.<br></div><div> This work uses observability analysis to investigate the relationship between desired resident space object characteristics and the information resulting from ground-based optical measurements. Observability is a concept developed in modern control theory for evaluating whether the information contained within measurements is sufficient to describe the dynamical progression of a system over time. In this work, observability is applied to Space Situational Awareness applications to determine what object characteristic information can be recovered from ground-based optical measurements and under which conditions these determinations are possible. In addition, the constraints and limitations of applying observability to Space Situational Awareness applications are assessed and quantified.<br></div>

Light curve inversion is a standard method to determine shapes, rotation periods and spin axis orientations of asteroids. This method can be extended to determine the size, albedo, thermal inertia and surface roughness parameters of an asteroid by including observations in thermal infrared. A solution of the Heat Conduction Equation (HCE) is necessary to model infrared flux from the asteroid. We analyse the accuracy requirements of the extended method for numerical solution of the HCE. We show that current implementation leads to errors in flux that are substantial. We recommend changes in the current implementation of the HCE solving approach to address the accuracy issues. We discuss uniqueness and stability of the solutions produced by the extended method as well as the accuracy of the determined parameters and their stability. Shapes of asteroids are produced and their physical attributes are determined based on light curve and infrared data.