The Transmission Control Protocol/Internet protocol (TCP/IP) interface for the Satellite Orbit Analysis Program (SOAP) provides the means for the software to establish real-time interfaces with other software. Such interfaces can operate between two programs, either on the same computer or on different computers joined by a network. The SOAP TCP/IP module employs a client/server interface where SOAP is the server and other applications can be clients. Real-time interfaces between software offer a number of advantages over embedding all of the common functionality within a single program. One advantage is that they allow each program to divide the computation labor between processors or computers running the separate applications. Secondly, each program can be allowed to provide its own expertise domain with other programs able to use this expertise.

For example, a telemetry acquisition system can handle the complexity of downloading data from the satellite, whereas SOAP can use such data to offer 3D displays and status information in a human-readable form. Both programs can operate efficiently, especially when they are hosted on separate machines. The SOAP TCP/IP interface supports the same rich command structure that its input file parser provides. The input is obtained and processed through the network instead of through files.

In addition, SOAP can bring additional analytical resources to bear against incoming data streams. SOAP can process these TCP/IP streams in a number of ways. It can access two simultaneous streams from different sources. This provides an added degree of flexibility in a real-time environment. The software can remain interactive while receiving data, allowing the user to configure different 3D views and data displays. For instance, a user can examine a 3D model based on orientation data streaming in from an independent source, such as the telemetry feed, or a robotic simulation such as the FORESIGHT software. Additionally, the SOAP TCP/IP interface can be configured in batch mode and reside on a server. Because SOAP can be tasked to automatically generate image and data files, it can be used to set up an automated Web site offering near real-time image and data reporting.

This software is portable and runs on four separate computer platforms: MS-Windows, Mac OS X, Linux, and Sun Solaris. There are no minimum hardware requirements other than that to run the host operating system. The host system should be capable of running OpenGL applications. SOAP performs best on the machines with good graphics hardware acceleration.

This work was done by Robert Carnright of Caltech and David Stodden and John Coggi of The Aerospace Corporation for NASA’s Jet Propulsion Laboratory.

The release of this software is controlled by the Air Force at Space and Missiles Center (SMC) in Los Angeles, California. The point of contact at SMC is 1Lt Matthew Nelson ( e-mail address: This email address is being protected from spambots. You need JavaScript enabled to view it. ). The use of this software is restricted to U.S.Government programs.

NASA Tech Briefs Magazine

This article first appeared in the February, 2009 issue of NASA Tech Briefs Magazine.

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