Astro-2 Public Affairs Status Report #3
6:00 a.m. CST (1/5:22 MET), March 3, 1995
Spacelab Mission Operations Control
Marshall Space Flight Center
Huntsville, Ala.


	The crew aboard Space Shuttle Endeavour spent most of their
first full day in space preparing three unique ultraviolet telescopes
to study celestial objects as part of the second Astro Observatory
(Astro-2) mission.  For nearly 16 days, these onboard telescopes will
give astronomers a view of the universe impossible to obtain from the
ground.

	Pilot William Gregory maneuvered the orbiter into different
attitudes, or positions throughout the night.  Payload Commander Tammy
Jernigan, Mission Specialists John Grunsfeld and Wendy Lawrence, and
Payload Specialists Ronald Parise and Samuel Durrance coordinated with
science teams at Marshall Space Flight Center in Huntsville, Alabama,
performing procedures to align and focus the Hopkins Ultraviolet
Telescope (HUT), Ultraviolet Imaging Telescope (UIT) and Wisconsin
Ultraviolet Photo-Polarimeter Experiment (WUPPE) last night.
Approximately 23 hours after launch, the Astro-2 instruments, nestled
in Endeavour's cargo bay, were being calibrated before observations of
the invisible universe began.

	While still in the calibration, or Observatory Commissioning
Phase, two of the three Astro-2 instruments, HUT and UIT science
teams, were locked onto an ancient supernova remnant.  This supernova
remnant is the result of a powerful explosion, which ended the life of
a massive star many thousands of years ago, and was used as a
calibration target for the telescopes.  During this mission, HUT's
spectrographs will help scientists determine temperatures, densities
and chemical compositions of gases in the supernova remnant while the
UIT will image the filaments of excited gas in the supernova remnant.
HUT Guest Investigator Dr. John Raymond of Cambridge, Mass., will
obtain information about the shock waves energizing these nebulae.

	The first science observation for Astro-2, a supernova remnant
known as Cygnus Loop, began just before the Space Shuttle Endeavour
crossed the South Atlantic Anomaly early this morning.  Since this
South Atlantic area is a region of intense particle radiation that can
affect detectors in the telescopes, crew members secured the
instruments until the orbiter had moved away from the anomaly.  The
observation of Cygnus Loop then continued until the supernova remnant
was out of the telescopes' field of view.

	The HUT telescope continues in the calibration phase.  HUT,
developed at the Johns Hopkins University in Baltimore, Maryland, has
a 36-inch mirror to focus ultraviolet light into a spectrograph in the
middle of the telescope.  This spectrograph "spreads" light into a
spectrum, or band of colors, based upon the wavelength of the light.
Principal Investigator Dr. Arthur Davidsen and his colleagues will
study these spectra to determine the chemical composition,
temperature, densities and motion of the celestial objects being
observed during Astro-2.

	The UIT made its first deep, wide-field photographs in
ultraviolet light overnight.  After Endeavour lands, Principal
Investigator Theodore Stecher and the UIT science team in Greenbelt,
Maryland, will study the images made by this telescope during this
16-day mission, looking for answers to astronomical questions such as
the shapes of nearby galaxies in the ultraviolet, the properties of
massive hot stars in these galaxies, the evolution of low-mass stars
in clusters, and the nature of the dust and gas that fill the space
between stars.

	During the next 12-hour shift, the STS-67 crew will continue
to lock the HUT, UIT and WUPPE telescopes onto celestial objects to
help scientists gain a better understanding of our universe.