Orbit files will be also necessary for barycentric correction. The attitude files may be necessary to create exposure maps, and the rate files shall be used for deadtime correction. This stage will be run by GOs at their own sites, therefore the response generators have to be portable, and the calibration files should be distributed. When the scientific products have become automatically extracted in the standard processing, the corresponding responses will have to be also automatically generated, though developping such an automated system will take long time. This stage shall be exclusively conducted by GOs.
GOs make scientific consideration and judgment on their products and results.
They may even go back to Stage 4, if new calibration information is made available after they received data, or back to Stage 3, if they need to recreate the auxiliary files with different conditions. In any case, they will never have to go back to Stage 2 or earlier. Cosmic Journeys Part of the NASA OSS Structure and Evolution of the Universe theme.