Verification and validation of the SIRTF infrared spectrograph

Verification and validation of the Infrared Spectrograph (IRS) instruments, one of three science instruments on board the Space Infrared Telescope Facility (SIRTF), provided numerous challenges during pre-launch integration and test programs. The IRS provides low and moderate-spectral resolution spectroscopic capabilities form 4 to 40 microns. The IRS instrument shares a Combined Electronics (CE) with the Multiband Imagine Photometer for SIRTF (MIPS). The CE provides command and control capability for IRS and MIPS with a common Rad6000 processor and software baseline. Our V&V challenges include: (1) integrating JPL ground system software early in the instrument test phases (2) maintaining a solid flight software baseline while addressing software change requests throughout integration and (3) staffing a test team that is able to respond effectively to an ever-changing integration schedule. IRS also has an interesting V&V challenge to test the two small imaging sub-arrays which allow infrared objects with poorly known positions to be accurately located and placed into any of the IRS modules´ entrance slits. This paper presents methodologies that governed CE and IRS test programs from standalone instrument testing through Assembly, Launch and Test Operations and looks forward to Mission Operation. An overview of test goals, accomplishments and lessons learned are presented. JPL ground system interactions, software maintenance, and test staffing are emphasized.