Daily                News
Monday, July 19, 1993  Two Independence Square; Washington, D.C.  
Audio Service:202/358-3014      


 % STS-51 launch delayed;
 % HST observations;
 % JSC Director to retire.

Officials decided to scrub Space Shuttle's Discovery's STS-51 mission
Saturday, July 17, at about 8:52 a.m. EDT because all eight of the
solid rocket booster hold down bolts and the T-0 liquid hydrogen vent
arm, located on the side of the external tank, were prematurely charged
with current.  This charge is normally initiated at the T-18 second
mark in the countdown.

Schedules have been made to drain the orbiter's fuel cell storage tanks
and to disconnect or safe pyrotechnic initiator controllers in various
areas of the vehicle and payload.  Officials estimate this work will be
completed today, allowing time to troubleshoot the pyrotechnic racks
inside the mobile launcher platform.

At this time, a new launch date has not been decided.

* * * * * * * * * * * * * * * *

Recent NASA Hubble Space Telescope (HST) observations indicate that a
class of active galaxies further support the theory that they are
fueled by a massive black hole at the center.  This observation rules
out vigorous star formation as the alternative explanation for the
mysterious power source behind quasars and extremely bright galactic
nuclei.

Alexei V. Filippenko, Professor of Astronomy, University of California
at Berkeley, states that "Our observations provide perhaps the most
direct evidence to date that normal Seyfert galaxies and quasars are
not powered by a burst of star formation."  Filippenko further
explained that the most likely alternative is the standard model in
which the energy is provided by matter falling into a black hole.

The Seyfert galaxies are nearby galaxies with extremely bright central
regions that often obscure the much dimmer stars in the surrounding
galaxy. Quasars are among the most distant objects in the universe and
can be seen from earth because they are so bright.  Seyfert and
Quasars, collectively referred to as active galactic nuclei (AGN), give
off a enormous amount of energy.

A black hole is a theoretical object that is so compact its intense
gravity prevents even light from escaping.  In the standard model for
AGNs , dust, gas and stars falling into the black hole heat up as they
collide and release tremendous amounts of radiation.

Previous HST observation have found additional circumstantial evidence
for the presence of massive black holes in the core of active
galaxies:  dust disks, "light- cones" of ionizing radiation and
extremely dense stellar concentrations consistent with theoretical
models for the presence of a black hole.

* * * * * * * * * * * * * * * *

Johnson Space Center Director Aaron Cohen recently announced his
retirement effective August 20.  Cohen has accepted appointment as the
Zachry Professor of Engineering at Texas A&M University.  Paul J.
Weitz, Deputy Director of the Johnson Space Center, will act as
Director upon Cohen's departure.

Cohen has more than 33 years of distinguished service with the
government, 31 of those years with NASA.  NASA Administrator Goldin
said "Aaron represents all of the finest you can hope for in a
government servant.  His career and his accomplishments speak for
themselves.  He provides a benchmark.  He has brought technical
excellence, integrity, dedication and leadership to the Johnson Space
Center and NASA.  His career serves as an example to us all, and he
leaves behind a lasting legacy."

Goldin announced that Cohen will serve as Special Consultant to the
Administrator on human flight as well as research technology along with
his responsibilities at Texas A&M.

 * * * * * * * * * * * * * * * *


        
Here's the broadcast schedule for Public Affairs events on NASA TV.
Note that all events and times may change without notice and that all
times listed are Eastern.

Monday, July 19, 1993

        noon      NASA Today.
        12:15 pm  The Night Sky with Dr. Rich Terrile.
        12:30 pm  America's Wings.
         1:00 pm  Apollo 10 Sorting Out Unknowns.
         1:30 pm  Magenetic Effects In Space.
         2:00 pm  Starfinder #3.
         2:30 pm  Our Laboratories in Space.
         3:00 pm  TQM #3.

Tuesday, July 20, 1993

        noon       NASA Today.
        12:15 pm   Aeronautics & Space Report.
        12:30 pm   Apollo 11 Anniversary/KISS: Apollo.
         1:00 pm  Apollo 11: For All Mankind.
         1:30 pm  Return to the Red Planet.
         2:00 pm  Starfinder #4.
         2:30 pm  Life on the Moon.
         3:00 pm  TQM #4.

        
The editor is  Sonja Maclin  on  202/358-1761 or SMACLIN on NASAmail.
NASA TV is carried on GE Satcom F2R, transponder 13, C-Band, 72 degrees
West Longitude, transponder frequency is 3960 MHz, audio subcarrier is
6.8 MHz, polarization is vertical.