The Extreme Ultraviolet Explorer Mission
(7 June 1992 - 31 January 2001)
The Extreme Ultraviolet Explorer (EUVE) was a NASA-funded astronomy mission
operating in the relatively unexplored extreme-ultraviolet (70-760
Angstroms in wavelength, equivalent to 0.016-0.163 keV in energy) bandpass.
The science payload, which was designed and built at
the Space Sciences Laboratory at the University of California, Berkeley,
under the direction of Dr. Roger F. Malina, consisted of three
grazing-incidence scanning telescopes and an extreme-ultraviolet (EUV)
spectrometer/deep survey instrument. The science payload was attached to a
Multi-Mission Modular spacecraft.
The EUVE mission was launched on June 7, 1992 on a Delta II rocket from
Cape Canaveral. The first six months of the mission were dedicated to
mapping the EUV sky with the scanning telescopes. Subsequent to that, the
mission carried out its Guest Observer phase. The science goals of EUVE were
to (i) carry out an all-sky, all-band survey in the extreme ultraviolet (70-760
A) in four bandpasses, with an angular resolution of 6 x 6 arc minutes and
~ 500 seconds average exposure, (ii) carry out a deep survey in the EUV in
two bandpasses along the ecliptic, (iii) carry out pointed spectroscopy
observations of targets identified by Guest Observers, (iv) identify the
emission physics of EUV sources such as hot white dwarfs and late-type,
coronal stars, (v) study the interstellar medium, and (vi) probe whether
compelling science could be done with increased sensitivity in the EUV.
Late in 1997, NASA decided that the EUVE final data archive
responsibilities should be transferred from the Center for
Extreme-Ultraviolet Astrophysics (CEA) to the HEASARC, the Space Telescope
Science Institute (STScI), and the National Space Sciences Data Center
(NSSDC). The role of the HEASARC is to serve the publically available EUVE
data and to act as an interface to the community of high-energy (X-ray and
gamma-ray) astrophysicists, while that of the STScI is to provide similar
access to the optical and UV community, as well as to maintain the EUVE
IRAF-based software package. The role of the the NSSDC is that of a deep
archive for the EUVE data and the servicing of requests for large amounts
of EUVE data, i.e., for data volumes that are infeasible to retrieve over
the Internet/WWW.
In the summer of 2000, NASA decided that EUVE mission operations should
cease within a few months. EUVE science operations ended on January 26, 2001,
and there followed several days of end-of-life mission engineering tests
of the never-used backup high voltage supplies and checking of the remaining
battery capacity. EUVE was stabilized pointing away from the Sun and
sent into safehold at 23:59 UTC on Jan 31 2001. The transmitters were
finally commanded off on Feb 2 2001. EUVE was left in a 424 x 433 km x
28.4 deg orbit which slowly decayed until it finally re-entered the Earth's
atmosphere and was destroyed on Jan 30 2002, almost exactly one year after
it ended science operations.
On March 27 2001, the CEA ftp and Web sites were closed down, although
many of the CEA Web pages were moved to either the main UC Berkeley
Space Sciences
Laboratory web site or to the
Multi-Mission Archive at Space Telescope (MAST).