‘Deep Impact’ spacecraft uses Express Logic’s RTOS, Green Hills Software’s IDE

More embedded control products are finding their way into harsh-environment space exploration projects.

By Control Engineering Staff August 11, 2005
This image—taken by the mission’s high-resolution camera aboard Deep Impact’s Flyby spacecraft—shows comet Tempel 1, 67 seconds after it obliterated the Impactor spacecraft. (Image courtesy of NASA/JPL-Caltech/UMD.)

More embedded control products are finding their way into harsh-environment space exploration projects. One remarkable example was NASA ’s recent Deep Impact spacecraft mission, in which ThreadX real-time operating system (RTOS) from Express Logic Inc . and Green Hills Software ’s Multi IDE (integrated development environment) played key roles. Deep Impact—consisting of separate Flyby and Impactor spacecraft—successfully deployed Impactor to collide with deep-space comet Tempel 1 and excavate material from the comet’s nucleus. Designed and built by Ball Aerospace & Technologies Corp. , the spacecraft pair reportedly incorporated some of the most sophisticated technology ever developed for deep-space flight.

Express Logic’s small-footprint ThreadX RTOS managed the operation of CCD camera controllers in Deep Impact’s three principal instruments. It controlled the high-resolution imager (HRI), medium-resolution imager (MRI), and impactor targeting sensor (ITS), which guided Impactor onto a collision course with the comet and collected scientific data before, during, and after impact. “In all three controllers, ThreadX managed application threads scheduling, performed interrupt servicing, and passed messages needed for the cameras to perform their difficult mission,” according to developers.

All project software was developed with Green Hills Software’s Multi IDE tool for embedded applications, using C, C++, Embedded C++, and Fortran languages. Multi IDE runs on Microsoft Windows, Linux or UNIX hosts; it also supports remote debugging to a variety of target environments. ThreadX RTOS is fully integrated with Multi IDE and includes kernel-aware debugging, preconfigured project building, source-code browsing, and EventAnalyzer execution logging for system and application-event monitoring.

Express Logic and Green Hills Software each expressed great pride in their successful participation in Deep Impact’s challenging mission to “further our understanding of the origins of the universe”—timed to culminate on July 4, 2005.

—Frank J. Bartos, executive editor, Control Engineering, fbartos@reedbusiness.com