Data management subsystem software architecture for JWST

Abstract

At the Space Telescope Science Institute, the Data Management Subsystem (DMS) is responsible for data reformatting from telemetry to FITS, pipeline calibration, and providing the data archive. A DMS has been previously developed for two astronomical telescopes in space, the Hubble Space Telescope and the Kepler Mission. DMS software analysis and design has begun for the James Webb Space Telescope (JWST), which is scheduled for launch in 2014 by the National Aeronautics and Space Administration. Although there will be a great deal of software reuse from the previous missions, differences in the operations concept for JWST will have implications for the DMS software system architecture. A number of the design challenges for the DMS software system architecture that result from the JWST operations concept will be considered. Event-driven operations, which mean the detailed observation schedule cannot be predicted ahead of execution time, will require extensive changes to the data flow at the beginning of DMS science data processing. A scheme for priority processing of exposures must be implemented to insure rapid turn-around on time critical wave front sensing data. JWST science data product design will reflect infrared detectors utilizing up-the-ramp processing. The concept of an observation in program planning will result in a new model to associate exposures and form higher level data products. In addition, the JWST DMS will introduce a new paradigm for reprocessing to meet data user demands and be compatible with the Virtual Observatory protocols.