ATLAS-3 STATUS REPORT 01

         
ATLAS 3 Public Affairs Status Report #1
6:00 p.m. CST, Nov. 3, 1994
Spacelab Mission Operations Control
Marshall Space Flight Center
Huntsville, Ala.

    The third Atmospheric Laboratory for Applications and Science (ATLAS
3) payload is in orbit aboard the Space Shuttle Atlantis, ready to paint a
more complete picture of the Earth's atmosphere, how the sun affects it,
and how human activity is changing it. 

    The seven atmospheric and solar instruments from the previous ATLAS
missions have reinforcements this flight - two new atmospheric experiments
mounted on the German space agency's deployable CRISTA-SPAS satellite. 

    The ATLAS 3 mission will make the first detailed measurements from the
Shuttle of the Northern Hemisphere's middle atmosphere in late fall.  The
timing of the flight, when the Antarctic ozone hole is diminishing, allows
scientists to study possible effects of the ozone hole on mid-latitudes,
the way Antarctic air recovers, and how the northern atmosphere changes as
the winter season approaches. 

    Payload Commander Ellen Ochoa, a veteran of the ATLAS 2 mission,
finished activating Spacelab systems at 1:34 p.m. CST.  Ground controllers
at Spacelab Mission Operations Control in Huntsville, Ala., completed
commands to power up the ATLAS payload at 2:30 p.m, three and a half hours
after launch. 

    The first ATLAS 3 experiment operation was a test of the Atmospheric
Trace Molecule Spectroscopy (ATMOS) experiment's sun tracker.  The
experiment, provided by NASA's Jet Propulsion Laboratory, views the
atmosphere illuminated by the rising and setting sun to measure the
quantity and distribution of 30 to 40 atmospheric gases - more than any
other space instrument.  The sun tracker's motorized mirrors follow the
sun as it moves in relation to the orbiter, reflecting sunlight onto the
instrument's detectors.  Commander Don McMonagle maneuvered Atlantis so
the experiment team in Huntsville could receive real-time video as they
commanded the tracker to scan from the middle to the edge of the solar
disk.  "This is the first time we have been able to compare video of the
tracker's actual movements with the commands we sent," said Principal
Investigator Dr. Mike Gunson.  "We found the instrument is positioned very
accurately, and this gives us an important reference point for commanding
throughout the mission."  ATMOS made its first science observation of an
orbital sunrise at 4:30 p.m. 

    Mission Specialist Joe Tanner used the orbiter's Remote Manipulator
System arm to power up the CRISTA-SPAS satellite for a Cryogenic Infrared
Spectrometers and Telescopes for the Atmosphere (CRISTA) status test.  The
experiment, one of two onboard the satellite, is encased in a
thermos-bottle-like vacuum container cooled with super-cold helium.  This
prevents heat given off by the instrument from interfering with its
readings of cool, infrared radiation in the atmosphere.  After its
deployment, the satellite will follow about 24 to 44 miles (40 to 70
kilometers) behind the Shuttle for a week, adding new insights on the
distribution of gases which contribute to ozone chemistry in the middle
atmosphere. 

    Tonight, Germany's Millimeter Wave Atmospheric Sounder will make its
first set of atmospheric measurements, and ATMOS will continue to monitor
orbital sunrises and sunsets.