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Mission Status Report #91      Star Date: November 8, 2005

The New FUSE Observatory

Caption: This figure shows portions of FUSE spectra of the same star, obtained in April 2005 (black) and again in October 2005 (red), demonstrating that the scientific capabilities (sensitivity and spectral resolution) of FUSE are unchanged. The spectra in the bottom panel have been offset slightly to allow a more detailed comparison. For comparison, this earlier report includes a comparison of data from March 2005 with a spectrum from prior to the reaction wheel failure. (Graphic courtesy of B-G Andersson and the JHU FUSE project.)

(Click graphic above to see larger version in a separate window.)

It has been a very busy time on the FUSE project over the last month and a half, on several fronts. We continued to develop, test, and improve our operations with a single reaction wheel, including the software tools on the ground that help us schedule observations safely and efficiently. We have also loaded and tested the "next generation" control software to FUSE, and this "brain transplant" was successful. Attempts to improve the system operations, both on the ground and in orbit, will continue in the background, but for now, the system we have is what we will have for the foreseeable future. That being said, last week I declared that the Observatory is back in science operations mode!

This is not to say the full capability of the "old" FUSE is available to us. With one operational reaction wheel, there are more restrictions on sky availability, and our method of doing business has had to adapt considerably from the old model. But we have demonstrated that the ability to observe at absolute declinations above 50 degrees (north and south) is viable and that the health of the scientific instrument remains excellent (see Figure above). We are back in business, but with a "new" Observatory, with different strengths and weaknesses from the old one.

So what does declaring ourselves back in science operations mean? Well, it does not mean that all our problems are behind us. We have limited run-time with our new control software, and there will undoubtedly be glitches and bumps in the road as we go forward. But by being in science operations, it means that, to the extent possible, we will now make performing science observations the priority. Testing and improving the system further will be the background activity instead of the focus it has been over the last 10 months. It is a subtle but important step in our recovery.

The next several months are an important demonstration period for us as we look toward future operations. The response from the community for the FUSE Cycle 7 Call for Proposals (the first cycle incorporating the new pointing constraints) was gratifyingly strong. There is apparently plenty of good science to be done in the part of the sky we can access with the "New FUSE" and we look forward to doing it!

I offer continued thanks to the FUSE Sciences Operations team, including our partners on the Mission Operations Team from Honeywell Technology Solutions, Inc., and our contractor team at Orbital Sciences Corporation, as well as the JHU operations staff, for their efforts to date, and for their ongoing efforts as we continue to improve the New FUSE Observatory.

Reported by: Bill Blair, FUSE Chief of Observatory Operations

Last Update: November 8, 2005

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