In its earlier Hubble telescope launch, NASA officials were horrified to learn that the mirrors in the orbiting instrument had been ground to the wrong specifications and commissioned a space shuttle mission to replace them. With the Webb orbiting at a range about four times greater than the distance from the earth to moon, a field service call to Webb is going to be even more expensive than Hubble's.
That makes those who are responsible for the software that will run the telescope nervous. Different international agencies are working on the Telescope Guidance, Navigation, and Control system, its Command Data Handling system, and its Integrated Science Instrument Module, which houses four different light receiving instruments.
To insure as much quality review up front as possible, NASA is telling each participant it must design and develop software using the Unified Modeling Language, a modeling symbol and syntax that allows code to be generated from models. It's also requiring that developers use as many public software standards and interfaces as possible. In effect, it's mandated that developers for Webb use IBM's Rational Rose Real-Time, a development tool based on UML modeling and supporting standards for real-time operational environments.
NASA needs a single "systems development platform that would be reliable throughout the extensive life of the mission," said Glenn Cammarata, development lead for the Integrated Science Instrument Module flight software in a prepared statement issued by NASA and IBM on Thursday.
Rational Rose will impose code checks and verify project quality as work progresses on several fronts, noted Danny Sabbah, general manager of IBM Rational Software. The use of Rose by all developers means one architecture will rule multiple projects, "while protecting against expensive, unforeseen software issues," Sabbah said in the press release.
On Jan. 17, a key subsection of the James Webb telescope, the mirror backplane, successfully completed its test phase. NASA is using more rigorous upfront standards for both the physical device and the software.
The James Webb telescope will contain more instruments to measure the infrared spectrum than visible light. As such, it should be able to peer further back in time than Hubble was able to. Gathering visible and infrared light from the far reaches of the universe offers clues to the origins of stars and galaxies.
The telescope is named after NASA's second top administrator, James Webb, who laid the groundwork for the Apollo missions to the moon. He left NASA the year before the first successful landing on the moon.