WASHINGTON (08/21/2000) - Problems still exist in the development of displays for the International Space Station's primary command and control computers, NASA's Inspector General reported this month.
In an Aug. 11 report on the Portable Computer System and Data Display Process for the space station, NASA's IG said display development still has significant weaknesses that impact usability and reliability of the PCS. The problems exist despite efforts that have been made since the mid-1990s to improve problems with the software and display development.
The on-board PCS is a commercial laptop computer modified for flight use and loaded with commercial and custom software, according to the IG memo to NASA officials. It is the crew's primary interface for command and control of the space station and provides the crew with caution and warning information for the station. The PCS displays consist of graphical and nongraphical, or tabular, formats.
Problems identified by the IG included the inability of the crew to know about erroneous data. In addition, users have difficulty navigating windows and screens to perform a task based on the display design. The IG recommended constant crew involvement in the development of the displays to guarantee the best, most efficient human/computer interface.
"The ISS program does not have a coordinated, well-defined process for software engineering and software management," the report said. "The lack of such a process results in numerous problems with requirements control, configuration management, cost and schedule estimates and defect prevention."
The report included 11 recommendations to improve the management, tools and software development process for the displays, but the IG did not think NASA management's reply was responsive.
Joseph Rothenberg, NASA associate administrator for Space Flight, replied in writing that many of the recommendations reflect activities that are already under way. He suggested the IG reconsider the recommendations.
NASA is developing tools to improve its processes and shorten its display development time, Rothenberg said in his letter. He also said a software management plan has been in negotiations for the several months and is in the final stages of approval.