Estimation of thruster plumes for resident space object optical observation

With the ever-growing number of resident space objects (RSOs) surrounding the Earth, it is imperative that we develop techniques for determining their current and future state by leveraging a collection of radio frequency and optical observations to maintain space domain awareness (SDA). The state of an RSO at a future time is determined by its current state and the forces acting upon it. In theory, this prediction is trivial; however, knowing all of the forces is not practical. When a space object undergoes a maneuver, this simple extrapolation fails, and more measurements are required before an updated state estimate would be available causing tracking methods to fail. One means by which an RSO undergoes a maneuver, is by firing its thruster which provides a transient component to its signature. For example, many small satellites use Hall effect thrusters to perform station keeping. The emission from these thrusters can be up to three times greater than the rest of the satellite. This change in the signature provides information about the aspect of the RSO and the amount of energy expended by the engine to produce a thrust on the object. This information can be passed back to the state estimators to reduce the time necessary to update the RSO's state. In this paper, we present a model for estimating the upper bound of the signature change of an RSO due to thruster engagement. We then present our initial results of a rendered model both with and without a plume present.