Greetings to all. I am very pleased to contribute this article and I hope that this will be a regular feature of the AXAF newsletter. Before commenting on the general status of AXAF from my point of view, I would like to point out that Project Science for AXAF is more than a single person who represents the user community's interests on an occasional basis. I am ably supported by a number of extremely dedicated scientists at the Marshall Space Flight Center: Steve O'Dell, Allyn Tennant, Ron Elsner, Marshall Joy, Robert Austin, Jeff Kolodzieczjak, Brian Ramsey, and Martin Sulkanen.
A major development since the last newsletter has been the removal of AXAF-S - the segment that featured non-dispersive spectroscopy - from the AXAF Program. This was a decision made by the Congress of the United States last year. Fortunately, there remains the possibility of a launch of the instrument (the XRS) as part of the Japanese Space Program on Astro-E. This option is currently being studied both in the United States and Japan.
After seventeen years, we are entering a new phase in the development of AXAF. Most of the `Preliminary Design Reviews' have been completed, and `Critical Design Reviews' - where all designs are frozen - are coming upon us shortly. The completion of all eight pieces of glass (four paraboloid-hyperboloid pairs) by HDOS (Hughes Danbury Optical Systems) is progressing, and figuring and polishing will be finished by this time next year. Then, the glass elements will be iridium coated by OCLI (Optical Coating Laboratories, Inc.) in California, and the elements will be delivered to EKC (Eastman Kodak Corporation) for assembly into a telescope. In about two years the instruments will be completed and delivered to MSFC where they, together with the telescope will undergo several months of extremely detailed testing and calibration at the refurbished X-Ray Calibration Facility. The new facility (upgraded from that used for the Einstein Observatory) now features a larger test chamber to accommodate the AXAF 10 m focal length, and the distance between the X-ray sources and the telescope is over 500 m. Three X-ray sources, two monochrometers, and an array of subsidiary focal plane instrumentation will also be available as part of the calibration program. These activities, together with off-line calibrations of the focal-plane instruments and a program of synchrotron measurements of flats which will be coated at the same time and in the same facility as the optics, are the ground-based calibration program.
We (Project Science) are also in the process of soliciting inputs necessary to organize the observing program. Currently, we are emphasizing the questions (not the answers). Examples of such questions are: Should there be key projects? Should there be a quota system associated with the length of observations (e.g., 25% `long', 50% `medium', and 25% `short')? Should there be a minimum observation time? How should one avoid `source monopolies' by the Guaranteed Time Observers (GTOs)? We have solicited inputs from the ASC and its Users' Committee, and the Science Working Group. Of course suggested answers are also welcome, and we would be especially interested in examples of how an issue was dealt with on other programs - correctly or incorrectly. We would appreciate your input via e-mail to email@example.com.