Using AppletMagic(tm) to Implement an Orbit Propagator: New Life for Ada Objects

This paper will discuss the use of the Intermetrics AppletMagic tool to build an applet to display a satellite ground track on a world map. This applet is the result of a prototype project that was developed by the Goddard Space Flight Center's Flight Dynamics Division (FDD), starting in June of 1996. Both Version 1 and Version 2 of this applet can be accessed via the URL http://fdd.gsfc.nasa.gov/Java.html. This paper covers Version 1, as Version 2 did not make radical changes to the Ada part of the applet. This paper will briefly describe the design of the applet, discuss the issues that arose during development, and will conclude with lessons learned and future plans for the FDD's use of Ada and Java. The purpose of this paper is to show examples of a successful project using Oi AppletMagic, and to highlight some of the pitfalls that occurred along the way. It is hoped that this discussion will be useful both to users of AppletMagic and to organizations such as Intermetrics that develop new technology.