Satellite Survivability Module (SSM), Version 2.0

The Satellite Survivability Module (SSM) is an end-to-end, physics-based, performance prediction model for the effects of adversarial directed energy engagement of orbiting spacecraft. SSM was created as an add-on module for the Satellite Tool Kit (STK). Two engagement types are currently supported: laser engagement on the focal plane array of an imaging spacecraft and Radio Frequency (RF) engagement of spacecraft components. This paper will focus on the laser engagement scenario, the process by which it is defined, and how we use actual laser effects data to help validate the SSM tool. SSM allows the user to create and implement a variety of "what if" scenarios. Satellites can be placed in a variety of orbits. Threats can be placed anywhere on the Earth or, for version 2.0, on other satellites. Satellites and threats can be mixed and matched to examine possibilities. Protection techniques for a particular spacecraft can be turned on or off individually, and can be arranged in any order to simulate more complicated protection schemes. Results can be displayed as 2-D or 3-D visualizations, or as textual reports. A new report feature available in version 2.0 will allow laser effects data to be displayed dynamically during scenario execution. In order to test SSM capabilities, the Ball team used SSM to model several engagement scenarios using actual lab and field test data. Actual laser, optics, and detector characteristics were entered into SSM to determine what effects we can expect to see, and to what extent. We concluded that SSM results match reasonably close to actual lab and field test results. 1. SSM INTRODUCTION Protecting space assets against laser threats is a growing concern in the defense community. To address this concern, the Ball team developed an easy-to-use, industry accepted, satellite survivability tool called the Satellite Survivability Module (SSM). The SSM is an end-to-end, physics-based, performance prediction model for the effects of directed energy weapon attacks on domestic satellites. End-to-end means that the SSM models a laser from the source (ground, air, or space-based), propagates it through the atmosphere (if applicable) to the spacecraft, and then models it through the imaging system to the detector. At the detector, we model four laser effects: degradation, saturation, damage, and catastrophic damage. These effects can be calculated with or without the presence of laser protection techniques. Physics-based means that SSM uses first principles physics to develop the propagation and effects models. Performance prediction means that SSM models predict the effect on the spacecraft's imaging system, and provide a basis for expected performance during engagement. SSM results are presented textually, graphically, and/or dynamically. Textually, time intervals when laser effects occur can be reported during the satellite's orbit. Graphically, these time intervals can be displayed as different color bands on the satellite's orbit-trace. Dynamically, laser effects calculations, such as at-orbit irradiance, or saturation, can be displayed while the simulation is running. SSM leverages the capabilities of Satellite Tool Kit (STK), an industry accepted, independently validated and verified satellite simulation tool. SSM was developed as an add-on module for STK, and takes advantage of STK's extensible architecture to enhance its capabilities. By expanding on STK's extensive capabilities, it allowed us to focus our efforts on laser effects calculations, and not on modeling orbital dynamics. SSM models the laser object, and STK provides the platform where the laser resides, whether it is ground, sea, air, or space, and allows the SSM laser to inherit the properties of the platform. SSM models the imaging system, and STK provides the imaging system platform defined as a satellite-sensor pair, and allows the SSM imaging system to inherit the properties of the satellite-sensor. SSM models laser effects on the imaging system during laser engagement, and STK determines the laser engagement period, which it calls access. SSM reports laser effects textually, visually, or dynamically, and STK provides the 2-D or 3-D visual displays.