NASCAP-2K: An Overview

Abstract Nascap-2k is the modern replacement for the older 3-D charging codes NASCAP/GEO, NASCAP/LEO, POLAR, and DynaPAC. Built on the DynaPAC kernel and incorporating surface charging, environment and space potential models from the older codes, Nascap-2k performs charging calculations for a wide variety of space environments under control of a unified graphical interface. In this paper we illustrate the use of Nascap-2k for spacecraft charging calculations. We touch on some of the unique physical and mathematical models on which the code is based. Examples/demos include the use of Object Toolkit, charging calculations in geosynchronous substorm, solar wind, low earth orbit, and auroral environments, and display and analysis of surface potentials, space potentials and particle trajectories. Introduction The recently released version 2.0 of Nascap-2k builds on the physical principles, mathematical treatments, computational algorithms, and user experience developed during over two decades of spacecraft charging research. Using Nascap-2k’s graphical user interface (GUI) a scientist or engineer with minimal knowledge of spacecraft charging can easily set up, run, and analyze standard problem types in geosynchronous, low-earth-orbit, auroral, and solar wind environments. A more adventurous user can, within the Nascap-2k framework, go beyond the standard problem types to investigate novel or specialized spacecraft environment interactions. Nascap-2k presents three GUIs to the user. The main Nascap-2k GUI is concerned with environment specification, calculation strategy, and results display and analysis. Object Toolkit