Spacecraft Charging Interactive Handbook (2001)

Recent spacecraft failures have brought into focus the need for increased understanding and modeling of spacecraft charging by spacecraft designers. Spacecraft charging assessments are needed for designing all geosynchronous, midaltitude, and polar, low-earth orbit spacecraft. Under contract to the Spacecraft Environment Effects Program office at NASA/Marshall, we are developing a CD-ROM/web based multimedia interactive Spacecraft Charging Handbook with integrated, updated spacecraft charging models. This product guides the nonexpert through the appropriate analysis using the power of sophisticated charging analysis tools. It is easy to use and will be accessible over the web. The onedimensional surface charging tools use the same physics as the NASCAP/GEO code. Over three years, six assessment modeling tools will be developed and incorporated. We have completed the Spacecraft Environment and Surface Charging tools. The Internal Charging tool is under development. During the second and third years a Three-dimensional Surface Charging tool, a Material Properties Database tool and an Auroral Charging tool will be developed. Introduction Under contract to the Spacecraft Environment Effects Program office at NASA/Marshall, we are developing a CD-ROM/web based multimedia interactive Spacecraft Charging Handbook with integrated, updated spacecraft charging models. This product guides the nonexpert through the appropriate analysis using the power of sophisticated charging analysis tools. Figure 1 shows the home page of the Handbook. Figure 1. Home page of the SEE Spacecraft Charging Interactive Handbook. There is a critical need for increased understanding and modeling of spacecraft charging by spacecraft designers. Spacecraft charging assessments are needed for designing all geosyn-chronous, mid-altitude, and polar, low-earth orbit spacecraft. The 1984 Design Guidelines for Assessing and Controlling Spacecraft Charging Effects (Purvis, et. al., 1984) needs extending for use with modern spacecraft. Additionally, the standard spacecraft charging code, NASCAP/GEO, is a complex tool/code to use, it does not address buried charge buildup, is limited with respect to the geometry it can model, and requires expertise to use. This application applies the advances in interactive communications using personal computers to spacecraft design technology. It provides NASA and commercial satellite designers and managers, spacecraft charging researchers, and aerospace engineering students information on how to build satellites using advanced technologies that can survive the natural environment. Deep dielectric charging due to penetrating electrons (Wrenn, 1995) and reverse polarity differential charging on solar arrays (Katz, et. al., 1998) are just two of the phenomena studied by researchers that are critically important to spacecraft design engineers. For maximum accessibility, the Handbook is written with HTML, Javascript, and JAVA and runs within a level 4 browser, either Internet Explorer or Netscape Navigator. This choice insures that the application can run on both Windows (95 or NT 4.0) and Macintosh OS 7.5 computers, either stand alone or over the World Wide Web. The application is navigated using the table of contents on the left side of the page. There are two main sections of the Handbook: Guidelines and Tools. The Guidelines is a text document that provides guidance to the spacecraft design engineer. The Interactive Tools allow users to investigate the charging of their spacecraft. The tools have a simple intuitive design. The essential physics needed to understand and predict the charging phenomena is included in the tools. The Design Guidelines consists of four sections: Spacecraft Charging Overview, Interactions Modeling Techniques, Spacecraft Design Guidelines, and Control and Monitoring Techniques. The Guidelines are accessed by clicking on the word “Guidelines” in the table of 6th Spacecraft Charging Technology Conference, AFRL-VS-TR-20001578, 1 September 2000