Number 13, October 2000


1)  Senior Review Results - FUSE Extended Mission
2)  Reaction Wheel Hiccup.
3)  Cycle 2 update
4)  FUSE Publication Acknowledgement
5)  FUSE data reduction pipeline to be released
6)  New GI Support Scientist at JHU
7)  GI visits to JHU invited
8)  IRAF Support Update
9)  Next FOAC meeting scheduled for November 3
10) Send List Update

1) Senior Review Results - FUSE Extended Mission

        FUSE was one of the missions under scrutiny at the recent meeting of 
the NASA Senior Review.  We are happy to inform you that we came through with 
flying colors, receiving very high grades both in terms of "Science per dollar" 
as well as in absolute science ranking.  As a consequence, the Senior Review 
recommended that FUSE be granted a two year extended mission.  The extended 
mission, nominally beginning in December 2002, will be entirely dedicated to 
Guest Investigator programs.

2) Reaction Wheel Hiccup.

        Slews and attitude control on FUSE are performed and controlled by
a set of reaction wheels.  In normal operations we are in a redundant, four 
wheel configuration, with wheels in the pitch, roll and yaw directions plus a 
skewed wheel with angular momentum components along each of the axes.
        In early August, the pitch axis reaction wheel started drawing increased
currents, indicating increased drag, and was shortly thereafter autonomously 
turned off by the on board fault checking algorithms.  For a number of weeks 
thereafter we were in three wheel control mode.  While not causing any 
significant loss of pointing or slewing accuracy, this mode provides no 
redundancy and was deemed highly undesirable as a long term state.
        After a review of the problem by the reaction wheel vendor it was 
agreed that the most likely cause of the anomaly was air bubbles in the Kapton 
tape lining of the reaction wheel housing.  The spacing between the wheels and 
the housing is very small and in order to mitigate problems due to vibrations 
during launch, the inside of the housing had been covered by Kapton tape.  
During this process it was deemed likely that microscopic air bubbles were 
caught under the tape.  In the zero-g environment of flight, some of these 
bubbles might have coalesced with the resultant bigger bubble becoming large 
enough to start rubbing against the spinning reaction wheel.
        In mid September, we put this hypothesis to the test by spinning the 
pitch wheel back up, to see if we could "wear down" the possible bubble.  After 
a day of tests and telemetry tracking, the drag did indeed drop back to 
close to the nominal level confirming the fault scenario.  Based on these 
results we are now back in nominal four wheel mode operation.  The drag on the 
pitch wheel is now the same as the other 3 wheels.
3) Cycle 2 update

        The FUSE cycle 2 proposal process is in its final stages.  We received 
134 proposals, requesting approximately 9Msec of observing time, yielding about
a factor 2.5 oversubscription rate.  The TAC meeting was held in Arlington, VA,
during September 20-21.  If you proposed, you can expect to hear from NASA in 
the next few weeks.  Phase 2 template files and support information will be 
e-mailed to successful Guest Investigators after the official announcement.
Users will have approximately four weeks to return their phase 2 inputs.

9) FUSE Publication Acknowledgement

        Papers based on FUSE observations should carry the following 
acknowledgement, preferably as a footnote to the title of the paper. This is
common practice with the main astronomical journals.

"Based on observations made with the NASA-CNES-CSA Far Ultraviolet 
Spectroscopic Explorer. FUSE is operated for NASA by the Johns Hopkins 
University under NASA contract NAS5-32985."

Authors are reminded to send a reprint of their FUSE publications to the FUSE 
Project Scientist, George Sonneborn. 

5) FUSE data reduction pipeline to be released

        We are nearing the time when the FUSE data reduction pipeline will be 
publicly released.  The public release version of the software has been 
generated and tested internally.  External "beta" testing by several of the PI 
team member institutions is under way.  Once we have some feedback from these
test sites, we will make the pipeline generally available for downloading from
our website.  We expect this to take place at the end of October.  We are 
in this release preparing versions for the Solaris and LINUX operating systems.
Installation and basic operations manuals will also be available.

6) New GI Support Scientist at JHU

        Please join us in welcoming Dr. Ravi Sankrit onboard as FUSE "Guest 
Investigator Support Scientist".  Ravi has most recently been a post-doc here 
at JHU, working with Bill Blair on supernova remnant observations using both 
FUSE and HST.  He can be reached at

7) GI visits to JHU invited

        Given the extra GI support staffing we invite the FUSE GI community to 
come to JHU for short visits.  If you feel it would be to your benefit to come 
here to sit down and look at your data or discuss some particular aspect of the 
data reduction or analysis, please contact us at, to 
set up the details.
        Please be aware that we are still severely manpower limited, so we are 
restricting the number of visitors we will accept to approximately two per month
and would expect a typical duration of each visit to be a few days.  Please view
these JHU visits primarily as ways to deal with nonstandard reduction needs or 
other special questions.  Given the number of programs in cycle 1 and the 
expected number of cycle 2 programs it should be noted that we will not be able 
to support visits from each program team.
        We have a guest cubicle available with an appropriate work station.  We 
do not, however, have the resources to subsidize travel or lodging.

8) IRAF Support Update

        Alert users of the FUSE IRAF scripts have reported a couple of bugs. 
We have therefore posted updated versions to the JHU web site.

9) Next FOAC meeting scheduled for November 3

        The next meeting of the FUSE Observer's Advisory Committee (FOAC) will 
be held at JHU on November 3.  The FOAC is the user community's voice to the
FUSE project.  If you have any issues or requests for the FOAC, please 
contact one of the FOAC members.  The FOAC chair is Prof. Steven R. Federman, 
of the University of Toledo (  The full membership 
listing can be found at:

10) Sendlist Update

        With the new e-mail inputs from the cycle 2 proposal round, we decided 
to perform a wholesale update on the e-mail exploder account through which this 
newsletter is distributed.  We hope that we managed to catch all duplications
in the resulting list.  If we didn't, we apologize and note that the way to 
remove an e-mail address from the send list is to send an e-mail to

with the following string in the body of the message:

unsubscribe fuse_news your-address@your-host

The Observer's Electronic Newsletter is published by the FUSE project and is
aimed at the FUSE user community.

Editor: B-G Andersson, FUSE Guest Investigator Officer.

The FUSE Project is managed by Johns Hopkins University's Center for 
Astrophysical Sciences in Baltimore, MD, for NASA's Goddard Space Flight 
Center.  The FUSE Principal Investigator is Dr. Warren Moos, the FUSE Project 
Manager at JHU is Mr. J.B. Joyce, and the NASA Project Scientist for FUSE 
is Dr. George Sonneborn.

Further information about the FUSE Guest Investigator Program can  be
obtained from:  Dr. George Sonneborn;

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