This has been a successful year for the AXAF Science Center, as it has been for the whole AXAF program. At the program level we are all excited by the early completion of the mirrors, the goal-level performance predictions from the mirror metrology, and early indications that the coated optics are also of goal-level quality. At the ASC we completed our Preliminary Design Review (PDR) in October '94, and we concluded the first of two Critical Design Reviews (CDR) in August of this year. Our staffing has continued smoothly and our team is 70% complete. The project has continued on schedule and within budget. One highlight was a visit to SAO in March by the NASA Administrator, Mr. Daniel Goldin.
During the last year we have staffed our three Beta Test Site teams at the University of Chicago, University of Hawaii, and Stanford University. The ASC staff member at each site will test portable software and remote user interfaces, and work on specific ASC tasks relating to the data system development, AXAF calibration, and mission planning.
The ASC has participated with the Project Office and other operations groups in defining the Integrated Operations Schedule (IOS) for incrementally developing and demonstrating the capabilities of the end-to-end system. The operations groups include the Flight Operations Team (TRW), the on-line and off-line data-system developers (MSFC and CSC, respectively), the MSFC Technical Support Team, and the ASC. The demonstrations involve all aspects of operations including the data systems, facilities, people, and procedures. The IOS requires operations to be ready to support the first AXAF end-to-end test 15 months before launch, and requires complete operational readiness at the final end-to-end test one month before launch.
Great effort went into preparations for the ASC PDR and first CDR. The focus for the first CDR was the design of the first two releases of the ASC Data System: the X-ray Calibration Facility (XRCF) release, and the Operations Control Center (OCC) release.
The XRCF release (4/96) will receive all test data taken during the AXAF ground calibration starting in September '96 at Marshall Space Flight Center. The data system will archive and process the data, and it will provide analysis tools for further analysis, generation of data products, and model comparison. The total test dataset is expected to be of order 200 GBytes, collected during 5 months of 24 hours per day testing: this presents a significant challenge from both a data management and a people management perspective. Preparations for the XRCF test are intensifying with significant effort being devoted to calibration planning through modeling and analysis of laboratory Science Instrument (SI) characterization data, in order to optimize the test time in the X-ray chamber (see AXAF at the X-ray Calibration Facility in this newsletter).
The OCC release (11/96) contains all the software required to interface with the OCC, perform the science mission planning functions, submit data to the OCC, and receive spacecraft telemetry and other data from the OCC. Note that proposal-submission tools are part of the third release of the data system (and our second CDR) and will be discussed in a future newsletter.
ASC staff have joined the other AXAF project groups in reviewing all aspects of the AXAF mission as the various elements have progressed through the PDR and in many cases CDR phase. The reviews have included the spacecraft and all its subsystems (aspect camera system, gyros, on-board computer, pointing system, etc), the SIs (ACIS, HRC, HETG and LETG), and the other operations elements.
In the data-systems area, activities have focussed on the development of the software and hardware design documents for PDR and CDR, and working with the science teams to develop a detailed understanding of the analysis steps and tools needed to process the SI laboratory data, XRCF data, and on-orbit AXAF data. Prototyping has included a hardware test bed, processing pipeline control, a data model for analysis, data-base and archive queries, and the science scheduling tool. Also, the ASC archive system for use during XRCF was recently delivered.
The ASC has been working closely with the SI teams in the planning and assessment of the characterization data taken in the laboratory as part of SI development and integration. The data are vital inputs to the XRCF and on-orbit calibration planning, and permit experience to be gained with processing and analysis software, data archiving, and data retrieval.
The ASC Mission Planning Group completed the first release of the AXAF Guide-Star Catalog and the AXAF Guide-Star and Acquisition-Star Selection Algorithm. Both have been delivered for use within the off-line system component of the OCC and by the TRW operations group in their planning for AXAF operations.
The ASC User Support Group organized the third AXAF Users' Committee meeting in June, and developed a draft policy recommendation document guided by discussions with the Users' Committee and with the AXAF Science Working Group (SWG). In addition, they have been coordinating user documentation within the ASC and leading the efforts to make maximum use of the World Wide Web and associated standards.
We face an exciting year ahead with the second CDR, the first release of the data system, final preparations for AXAF ground testing, and the momentum which is building in the operations area. In addition, we will work closely with the SI teams in assessing and supporting the analysis of laboratory data as the SIs are integrated and tested.
