Engineering Data Services for the JWST Data Management System

The James Webb Space Telescope (JWST) data management subsystem (DMS) includes an innovative new engineering database (EngDB) system following a service-oriented architecture that ingests data, manages processes, and serves data to pipelines and the community. EngDB services are implemented using a RESTful architectural style to drive processes and access data via the well-defined HTTP protocol. JWST will generate roughly 5 TB of calibrated engineering data per year, with up to 300 million samples per day for 20000 parameters. Given the nature and volume of the data, separate databases are used to store approximately 2000 frequently-accessed parameters and many more rarely-accessed parameters from each instrument and other observatory components. This decomposition provides us with a natural way to provide operational robustness by duplicating the frequently-accessed database in operations to support the pipelines and in the Mikulski Archive for Space Telescopes (MAST) to support public access. For many previous missions, getting time series engineering data into the hands of observers was quite difficult. Access to the full time series of JWST engineering telemetry will enable scientific researchers and instrument scientists to identify and correct calibration artifacts that correlate with engineering parameters. This type of analysis can be very useful, for example when analyzing exoplanet transit data where the highest possible precision is needed.