May 9, 2007 Dear Colleagues, On May 8, 2007, FUSE went into safe mode following an anomaly with the skew reaction wheel. Science operations have been suspended while the FUSE project and NASA diagnose this problem. We do not yet know the prognosis for restarting the stalled wheel, which is required for science pointing and slewing. Those of you who have Cycle 8 observing programs recently were sent letters from NASA HQ about submitting budgets by June 30, 2007. If necessary, the deadline will be extended due to this interruption in the science program. The instructions for submitting budgets, which are immediately relevant to those who already have Cycle 8 observations, will be posted in the FUSE GI web site this week. Cycle 8 PIs are asked to precede with their budget preparations as planned. George Sonneborn FUSE Project Scientist June 14, 2007 Dear FUSE Community, I am delighted today to be able to tell you that FUSE is back in science operations! After a month of intensive effort by the FUSE operations team here at JHU, the observatory was brought back on-line late Tuesday evening, June 12, 2007. The skew reaction wheel was brought back into service on Thursday May 24, and has been spinning since that time. The initial performance was uneven, but settled down after the first 24 hours. Since that time, the wheel performance has continued to improve, and the friction levels and wheel performance are now essentially as they were prior to the anomaly. Remarkably, with continued use over the last several weeks, the wheel has returned to normal. And when I say we are back in operations, I mean it! We are on a science timeline with the doors open and the high voltage on the detectors. We are taking data. A preliminary look at the data obtained over the last 24 hours verifies that the scientific performance is nominal. Our mission planning team has currently generated science timelines through the end of the month, and reported no difficulty in doing so while keeping the wheel spinning in one direction, which is being done at least for now as a precautionary measure. We are once again back in business, and we have resumed executing the Cycle 8 science program! I would be remiss if I did not thank the many people on the FUSE operations team, at Honeywell Technical Solutions Inc., at Orbital Sciences Corporation, and at NASA/GSFC and HQ who have supported us over the last month during the recovery of science operations. It was an amazing effort. Thanks for your continued support of and interest in the FUSE mission. Bill Blair FUSE Deputy PI and Chief of Observatory Operations P.S. As a reminder, FUSE Status Reports are posted on our web page, http://fuse.pha.jhu.edu July 19, 2007 Dear Colleagues, On Thursday evening, July 12, 2007, the excess friction problem on the FUSE skew wheel returned. The wheel had at that time been operating perfectly for several weeks. Since that time, we have been primarily concerned with the health and safety of the spacecraft. We are currently assessing the anomaly and making every reasonable attempt to recover motion in the errant wheel. Please note that the ROSES solicitation for the FUSE Legacy Science Program (which replaces the previously planned Cycle 9) is proceeding as planned at this time, but with its continued implementation contingent on the successful recovery of the skew wheel. The FUSE Project Aug. 17, 2007 Dear Colleagues, As reported previously in the FUSE newsletter, the last operational reaction wheel on FUSE stopped temporarily in early May 2007. It was restarted and science operations resumed on June 12. However, on July 12 the wheel stopped again. This time the stoppage was very abrupt indicating a large braking force. Attempts to restart any of the wheels over the last four weeks have been unsuccessful. Although the instrument remains in excellent condition, the FUSE satellite is currently incapable of the fine pointing control required to continue its science mission, and there is no real prospect for recovering this capability. Regrettably, we have concluded that the scientific mission of the Far Ultraviolet Spectroscopic Explorer is no longer viable. The NASA Science Mission Directorate has accepted our recommendation to terminate the mission. The FUSE Project has started closeout activities and will complete the final CalFUSE 3.2 reprocessing of the entire science mission data set in mid 2008. The FUSE archive at MAST will be an ongoing legacy of the mission, and an important resource for years to come. Future editions of the FUSE Newsletter will provide details of our plans for the FUSE mission archive at MAST. Also, watch the FUSE web page for updates. The FUSE mission has been a fantastic success by any measure. 678 science programs (GI, PI team, and discretionary time) have obtained 67 Msec of observing time, over 5100 observations of about 2800 unique targets. There are over 430 peer-reviewed papers based on FUSE data and the number continues to grow. The story is not quite over, though. Twenty five of the 68 programs selected for Cycle 8 obtained data this Spring and Summer before the reaction wheel stopped for the last time. These data have been archived recently and should lead to further exciting results in the near future. Utilization of the FUSE archive will continue the flow of new results. The Astrophysics Division intends to place special emphasis on FUSE archival research in the 2008 Astrophysics Data Program that will be part of the 2008 ROSES proposal solicitation. The success of FUSE is a result of the combined efforts of the scientists and engineers who built and operated it plus the scientists who proposed, analyzed, and interpreted the observations. FUSE's legacy is a testament to the creativity, ingenuity, and hard work of al l of you. We acknowledge your efforts and enthusiasm with gratitude. George Sonneborn Warren Moos Project Scientist Principal Investigator NASA/GSFC Johns Hopkins University