On the evening of March 5, during normal spacecraft house-keeping
operations, the Sigma 5 ground computer (for reasons at present known
only to itself) sent three anomalous commands to IUE in succession.
One of those commands in effect turned off the electronics for the
gyro package, causing the two functioning gyros to spin down. When
the electronics was reactivated, one of the gyros did not resume
operation. At present, Operations Control Center personnel have
successfully transferred IUE control to the one-gyro system and are
solving a few related technical problems, and OCC, VILSPA, and NASA
staff are considering options for the future. The one-gyro system is
useful only for those targets having bright (say 8th magnitude or
brighter) guide stars in the Fine Error Sensor field of view when the
target is in the desired science aperture. The DAC will keep the
community appraised of the situation (readers are particularly
encouraged to check the IUE Web
This anomaly follows the recent announcement by ESA Science Director
Roger Bonnet that ESA did not plan to fund VILSPA IUE orbital
operations support beyond September of this year. This decision was
made in response to financial constraints at ESA. The text of the ESA
announcement can be found at http://www.vilspa.esa.es/iue/iuefin.html.
The libraries for the production and experimental software were updated for
the anonymous ftp distribution in early February. An updated version of the
Merged Log should be available in about a week. The VMS libraries can be
found at iue.gsfc.nasa.gov in the IUEDAC subdirectory.
Links to the Unix, Ultrix, PC
(Windows), and Macintosh libraries can be found on the IUEDAC web page.
The distribution form of the Mac software has also been changed to (hopefully)
simplify the installation. These files are now stored as self-extracting
archive files in BinHex4 format. They should be transferred in ASCII format
and then converted from BinHex4 format with an appropriate converter; one
can be found in the archive program Compact Pro under the Misc menu.
The files can then be extracted just by clicking on their names.
Hey, we're not proud! Who can afford to be now days? If you have
developed software to analyze IUE data that you think might be useful
to other users, and if you have an interest in making this code more
generally available, the DAC would like to hear from you! We are
considering establishing a subdirectory specifically for such
contributed code. IUE has traditionally benefitted greatly from this
kind of user input. Please contact Randy Thompson or Rich Arquilla.
During November through February, the IUE Project conducted an
educational project providing students with hands-on experience in
spacecraft operations and satellite astronomy. The brain-child of IUE
Project Scientist Dr. Yoji Kondo, and CSC's Peter Perry and Terry
Teays, the project made use of the time during which the IUE
spacecraft is parked for eight hours/day. Four students, two college
and two high school, were trained in conducting basic science
operations with IUE. Terry Teays was the instructor, with assistance
from other IUE Project staff, Judy Pepoy and Jim Caplinger, as well as
Fred Bruhweiler of the Catholic University of America. After training
"off-line", the students conducted real-time science operations
during several of the US Maintenance Shifts. They performed spacecraft
maneuvers, identified and acquired targets, obtained spectra, and
archived the data.
In addition to these activities, the students received lectures on
spacecraft operations in general, spacecraft hardware, ultraviolet
astronomy, and IUE data reduction and analysis. They also were given
lectures on the targets which they observed, so that they would
understand the nature of the objects and the scientific relevance of
the ultraviolet spectra.
The students' "final exam" was to conduct a shift during which the
Director of Goddard Space Flight Center, Joe Rothenberg, observed them
at work. They did an excellent job, and had a good time as well. It
was especially rewarding to see the excitement of NASA's space science
being communicated to these young people.