Mission Status Report #106 Star Date: June 8, 2007
On the Cusp of Recovery!
Caption: The FUSE satellite floats in front of an infrared image of the Carina Nebula, a region of intense star formation, taken with the Spitzer Space Telescope. Many hot stars within this nebula, including the enigmatic Eta Carina itself, have been the subject of intense study with FUSE observations. Joint observations at several wavelengths using facilities from ground-based telescopes to NASA space telescopes are needed to fully understand complex processes such as star formation. (Figure courtesy NASA and the FUSE project.)
Today marks one month since the FUSE satellite experienced a significant anomaly involving the skew reaction wheel, on May 8, 2007. I am delighted to report that we are poised to return to science operations over the coming week!
Over the last week. we have continued to develop and test an improved safemode that keeps a "bias" (non-zero spin rate) on the skew wheel. We have also performed two slews from safemode to the south orbit pole, which has verified that our new software simulators can predict actual performance at a reasonable level. We are presently in the process of bringing FUSE back to life, thermally conditioning the science instrument, ramping up high voltage on the detectors, and preparing to test the systems after a month-long hiatus. If everything goes according to plan, we should commence actual observations next week and be able to assess and verify the health of the scientific instrument at that time.
Analysis of the telemetry over the past several weeks has shown continued improvement in the performance of the wheel over time since it was restarted, and it is nearly back to pre-anomaly performance levels. As a conservative measure, we will begin operations while keeping the wheel spinning in one direction and avoiding low wheel speeds and "zero crossings." Our planning tools and operational procedures have been adjusted over the last week to make this happen. Timelines have been prepared for the coming weeks, and it appears that this is not an overly-restrictive requirement for science timelines.
The work is not done, but we are getting there! The improvements over the last week continue to be very encouraging. I want to express my continued thanks to the many people who are putting in long hours to bring FUSE back into an operational state, so we can get back to producing scientific data for our user community.
More information will be provided here, electronically to the FUSE users mailing list, and through the NASA project scientist's office at NASA/Goddard as the information becomes available.
Reported by: Bill Blair, FUSE Chief of Observatory Operations
Last Update: June 8, 2007
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