Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/DAILY_2/930716.DFC

Text File | 1993-07-31 | 30KB | 721 lines

16-Jul-93 Daily File Collection
   These files were added or updated between 15-Jul-93 at 21:00:00 {Central}
                                         and 16-Jul-93 at 21:00:11.

=--=--=START=--=--= NASA Spacelink File Name:930716.REL

7/16/93:  NASA AND GERMAN SPACE AGENCY SIGN SPACE AGREEMENT

Debra J. Rahn
Headquarters, Washington, D.C.
July 16, 1993



RELEASE:  93-129

    NASA and the German Space Agency (DARA) signed an agreement last night
to cooperate on four space missions using the retrievable German Shuttle Pallet
Satellite (ASTRO-SPAS).

    Daniel S. Goldin, NASA Administrator, and Professor Wolfgang Wild, DARA
Director General, signed the memorandum of understanding in Washington, D.C.

    The ASTRO-SPAS program involves combined U.S. and German science
payloads to be flown on a newly developed German- designed science satelllite.

    The first phase of the ASTRO-SPAS program consists of two missions, one
involving far and extreme ultraviolet astronomy and a second, to take infrared
and far infrared radiation measurements in the Earth's atmosphere.

    The first planned ASTRO-SPAS mission is the Orbiting and Retrievable
Far and Extreme Ultraviolet Spectrograph (ORFEUS- SPAS-1). In this mission, the
German ORFEUS instrument will be flown with one German and two U.S.
spectrographs.

    ORFEUS-SPAS-1 is currently scheduled for a Space Shuttle launch on July
17, 1993.  The objective of ORFEUS-SPAS-01 is to launch a
deployable/retrievable astronomical platform and obtain ultraviolet spectra for
both astrophysically interesting sources and the intervening interstellar
medium.

    The second planned ASTRO-SPAS mission is the first flight of the
Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere
(CRISTA-SPAS-1).  It is co-manifested with NASA's Atmospheric Laboratory for
Applications and Science (ATLAS-3) for a planned Space Shuttle launch in
September 1994.


    The objective of CRISTA-SPAS-1 is to explore the variability of the
atmosphere and to provide measurements to complement the ATLAS-3 science
objectives.  The CRISTA instruments and the Middle Atmosphere High Resolution
Spectrograph will provide trace gas measurements at locations in time and space
not available elsewhere, including an enhanced set of correlative measurements
in support of the Upper Atmosphere Research Satellite and other Earth-orbiting
atmosphere experiments.

    In the second phase of the ASTRO-SPAS program, NASA and DARA plan to
refly ORFEUS-SPAS in 1995 and CRISTA-SPAS in 1996 on the Space Shuttle.
     Source:NASA Spacelink    Modem:205-895-0028  Internet:192.149.89.61
=--=--=-END-=--=--=

=--=--=START=--=--= NASA Spacelink File Name:930716.SHU

KSC SHUTTLE STATUS REPORT 7/16/93




        KENNEDY SPACE CENTER SPACE SHUTTLE STATUS REPORT
                      Friday, July 16, 1993


KSC Contact: Bruce Buckingham

              MISSION: STS-51  ACTS-TOS/ORFEUS-SPAS
                           Launch minus 1 day


VEHICLE: Discovery/OV-103             ORBITAL ALTITUDE: 184 miles
LOCATION: Pad 39-B                    INCLINATION: 28.45 degrees
LAUNCH DATE: Saturday, July 17, 1993  CREW SIZE: 5
LAUNCH WINDOW: 9:22 - 10:24 a.m. EDT
EXPECTED KSC LANDING DATE/TIME: July 26 or 27  7:21 a.m. EDT
EXPECTED MISSION DURATION: 8 days/22 hours + 1 day (an additional
day on orbit may be granted if orbiter cryogenics allow)

     The countdown for Discovery's launch continues without problem at KSC's
Pad 39-B.  No technical or hardware issues are being worked.  Yesterday
operations to load the onboard cryogenic tanks with the liquid oxygen and
liquid hydrogen reactants was completed on schedule and the orbiter mid-body
umbilical unit, through which the reactants flow, was demated and retracted
away from the vehicle.  Communications activation and final vehicle and
facility closeouts are continuing today.  Also, time critical equipment and the
last two mid-body payloads, CHROMEX and CPCG, are being installed into the
orbiter.

     Earlier, the rotating service structure was rolled to launch position with
first motion occurring at 10:16 a.m. today.

     At about 1:00 a.m. tomorrow, the external tank will be loading with more
than 500,000 gallons of liquid hydrogen and liquid oxygen.  Operations toward
that milestone are proceeding without problem.

     Forecasters continue to indicate only 10 percent probability of weather
prohibiting launch with a slight chance of showers being the primary concern.
The winds at the pad are expected to be from the west-south-west at 4 to 6
knots; temperature 84 de- grees F.; visibility 7 miles; and clouds scattered at
3,000 and 25,000 feet.  A 24-hour or 48-hour delay will see about the same
conditions with a forecast 10 percent chance of violation each day.

     Today, the five-member astronaut crew for this mission have been given a
briefing on tomorrow's weather outlook and completed their review of launch day
activities and mission plans.  STS-51 Commander Frank Culbertson and Pilot
William Readdy will fly in the T-38 training aircraft this afternoon.  The
entire crew will be ready for sleep at about 6:30 p.m.  They will be awakened
tomorrow at 4:12 a.m.


        SUMMARY OF HOLDS AND HOLD TIMES REMAINING FOR STS-51


T-TIME ------- LENGTH OF HOLD ---- HOLD BEGINS ---- HOLD ENDS

T-11 hours --- 13 hrs., 32 mins. - 5:30 am Fri.----- 7:02 pm Fri.
T-6 hours ---- 1 hour ----------- 12:02 am Sat.----- 1:02 am Sat.
T-3 hours ---- 2 hours ----------- 4:02 am Sat.----- 6:02 am Sat.
T-20 minutes - 10 minutes -------- 8:42 am Sat.----- 8:52 am Sat.
T-9 minutes -- 10 minutes -------- 9:03 am Sat.----- 9:13 am Sat.





                      CREW FOR MISSION STS-51

Commander (CDR): Frank Culbertson
Pilot (PLT): Bill Readdy
Mission Specialist (MS1): Jim Newman
Mission Specialist (MS2): Dan Bursch
Mission Specialist (MS3): Carl Walz





           SUMMARY OF STS-51 LAUNCH DAY CREW ACTIVITIES


Saturday, July 17, 1993

4:12 a.m.      Wake up
4:42 a.m.      Breakfast
5:12 a.m.      Weather briefing (CDR, PLT, MS2)
5:12 a.m.      Don flight equipment (MS1, MS3)
5:22 a.m.      Don flight equipment (CDR, PLT, MS2)
5:52 a.m.      Depart for launch pad 39-B
6:22 a.m.      Arrive at white room and begin ingress
7:37 a.m.      Close crew hatch
9:22 a.m.      Launch


                          #   #   #   #
     Source:NASA Spacelink    Modem:205-895-0028  Internet:192.149.89.61
=--=--=-END-=--=--=

=--=--=START=--=--= NASA Spacelink File Name:930716.SKD

DAILY NEWS/TV SKED 7-16-93

Daily News
Friday, July 16, 1993
Two Independence Square; Washington, D.C.
Audio Service:202/358-3014


 % Spaceweek kicks off today;
 % STS-51 mission scheduled for launch tomorrow;
 % NASA  signs space agreement with German Space Agency.


Spaceweek kicks off today, July 16 and continues through until July 24.
Spaceweek is the annual celebration of the Apollo 11 lunar landing and a time
for all of us to reflect on the value of space exploration.  This year's theme
is "Space After the Cold War."

Numerous NASA astronauts will be traveling across the country this week to
speak at science museums and to historical societies.  NASA Administrator
Daniel S. Goldin will deliver a speech in Houston today as part of the
Spaceweek.

Several NASA field centers are sponsoring Spaceweek events, including a
day-long space fair at the Lewis Research Center on July 21, and a model
launch, lecture series and amateur radio satellite demonstration at the
Virginia Air and Space Center near the Langley Research Center. The National
Space Society is sponsoring the first annual "Race for Space," a 5k/1k run and
walk on the Mall at 8 a.m.  Sunday, July 18, here in Washington.

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

Tomorrow at 9:22 a.m.  EDT, Space Shuttle Discovery is scheduled to make its
17th voyage into space.  Discovery's STS-51 mission is scheduled to last nine
days with the possibility of an additional day added if enough onboard
cryogenic reactants are available.

The crew for this mission are Commander Frank Culbertson, Pilot William Readdy
and Mission Specialists Daniel Bursch, James Newman and Carl Walz. Discovery is
scheduled to land at the Kennedy Space Center.

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

Yesterday, NASA and the German Space Agency signed an agreement to work
together on four space missions using the retrievable German Shuttle Pallet
Satellite (ASTRO-SPAS).  The ASTRO-SPAS program involves combined U.S. and
German science payloads to be flown on a newly developed German designed
science satellite.


The first part of the ASTRO-SPAS program consists of two missions.  The first
mission involves far and extreme ultraviolet astronomy and a second, to take
infrared and far infrared radiation measurements in the Earth's atmosphere.

The first mission, ORFEUS-SPAS is scheduled launch on July 17 aboard Space
Shuttle Discovery. The objective of the ORFEUS-SPAS-01 is to launch a
deployable/retrievable astronomical platform and obtain ultraviolet spectra for
both astrophysically interesting sources and the intervening interstellar
medium.




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



         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.


Friday, July 16, 1993

Live      8:00 am       STS-51 Countdown Status Briefings.
        11:00 am        STS-51 Pre-Launch Press Conference.
          2:00 pm       Starfinder #2.
          3:00 pm       TQM #2

Saturday, July 17, 1993

Live      4:30 am       STS-51 launch coverage scheduled to begin.  L+60 min
            Post Launch News Conference NASA TV will cover the
            STS-51 mission from lift-off to landing.



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.
     Source:NASA Spacelink    Modem:205-895-0028  Internet:192.149.89.61
=--=--=-END-=--=--=

=--=--=START=--=--= NASA Spacelink File Name:930716A.REL

7/16/93:  HUBBLE SUPPORTS BLACK HOLE MODEL FOR ACTIVE GALAXIES

Paula Cleggett-Haleim
Headquarters, Washington, D.C.
July 16, 1993

Jim Elliott
Goddard Space Flight Center, Greenbelt, Md.

Ray Villard
Space Telescope Science Institute, Baltimore, Md.

RELEASE:  93-130

    A team of astronomers reports that recent NASA Hubble Space Telescope
(HST) observations of a class of active galaxies further support the theory
that they are fueled by a massive black hole at the center.

    The researchers say the HST results rule out vigorous star formation as
the alternative explanation for the mysterious power source behind quasars and
extremely bright galactic nuclei.

    "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," says Alexei V. Filippenko, Professor of Astronomy, University of
California at Berkeley. "The most likely alternative, then, is the standard
model in which the energy is provided by matter falling into a black hole."

    Seyfert galaxies are nearby galaxies with extremely bright central
regions that often obscure the much dimmer stars in the surrounding galaxy.
Quasars -- quasi stellar radio sources -- are among the most distant objects in
the universe and are visible from Earth only because they are so bright.

    Both types of objects, collectively referred to as active galactic
nuclei (AGN), give off prodigious amounts of energy.  Much of the radiation is
in the form of high-energy x-rays and gamma rays.

Convincing Observations

    Observations over the past 30 years have convinced most astronomers
that the only object capable of producing such tremendous amounts of energy in
a relatively small galactic core is a black hole.

    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 with
one another, releasing tremendous amounts of radiation.

    A competing explanation is the starburst hypothesis, which proposes
some active galaxies -- in particular so-called Seyfert galaxies and some
dimmer quasars -- are bright because of vigorous star formation at the center.
This starburst activity generates massive hot stars that evolve rapidly and
explode after a mere 10 million years.

    This model, championed by Roberto Terlevich of the Royal Greenwich
Observatory in Cambridge, England, predicts that light from the nucleus of an
active galaxy should show characteristics of light from very hot stars.  In
particular, it should show ultraviolet absorption lines -- specific wavelengths
in the ultraviolet part of the spectrum that are blocked or absorbed by cooler
gas in the atmospheres of the stars.

    "Terlevich's hypothesis was generally dismissed by astronomers, but we
felt it was conceivable that some of the least luminous active galaxies could
have enough stars in their nuclei to produce this amount of energy," Filippenko
says. "Among astronomers, there is a tendency to associate anything mysterious
with a black hole, but we thought it was important to test the hypothesis and
not jump on the black-hole bandwagon."

    The astronomers chose to use NGC 4395 to test the starburst hypothesis
because the region around the nucleus is nearly devoid of stars, which could
contaminate the spectra and make the findings ambiguous.

    Filippenko and his colleagues used the Faint Object Spectrograph aboard
the HST to make a 7-hour observation of the nucleus of NGC 4395.  They did not
detect any absorption lines that could be ascribed to stars in the nucleus.

    "We can say with confidence that there is no unambiguous evidence that
stellar processes are responsible for light emitted by the nucleus of this
galaxy," Filippenko says.

    In addition, an image of the galaxy obtained with HST's Planetary
Camera shows a galactic center at most 2 light years across -- less than half
the distance from the sun to the nearest star.

Starburst Hypothesis

    "This is smaller than all but the smallest star clusters, which are
extremely rare, " Filippenko says. "Although the size alone does not rule out
the possibility of a star cluster being responsible for the light, it makes
this unlikely." He concludes, "The starburst hypothesis doesn't work for this
nearby active galaxy, so it probably doesn't work for most others."

    The findings are reported in the June 20, 1993, issue of The
Astrophysical Journal by Filippenko, graduate student Luis C. Ho and California
Institute of Technology astronomer Wallace L.W. Sargent.

    Filippenko and Sargent identified NGC 4395 4 years ago as the least
luminous and nearest Seyfert galaxy known, based on its spectrum.  It is about
8 million light years away in the direction of the constellation Canes Venatici
(The Hunting Dogs).

    Seyfert galaxies, quasars and other AGNs are generally thought to
comprise only about one of every 100 known galaxies.  Based on a survey of more
than 500 galaxies over the past 10 years, Filippenko and Sargent think the
number may be closer to one in 10.

    Previous Hubble observations 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.

    Support for the research was provided by NASA through the Space
Telescope Science Institute and the National Science Foundation. The Hubble
Space Telescope is a project of international cooperation between NASA and the
European Space Agency.
     Source:NASA Spacelink    Modem:205-895-0028  Internet:192.149.89.61
=--=--=-END-=--=--=

=--=--=START=--=--= NASA Spacelink File Name:930716B.REL

7/16/93:  JSC DIRECTOR COHEN ANNOUNCES RETIREMENT

Jeffrey Vincent
Headquarters, Washington, D.C.
July 16, 1993


Jeffrey E. Carr
Johnson Space Center, Houston


RELEASE:  93-131


    Aaron Cohen announced today that he has accepted appointment as the
Zachry Professor of Engineering at his alma mater, Texas A&M University, and
will retire as Director of the Johnson Space Center effective August 20th to
assume his engineering faculty duties when the fall term opens at the end of
August.

    Paul J. Weitz, Deputy Director of the Johnson Space Center, will become
Acting Director at Cohen's departure.

    Cohen culminates a career with the government of more than 33 years of
distinguished service, including two years of commissioned service with the
U.S. Army. He came to NASA in 1962 and served in key leadership roles in the
Apollo Program, where his efforts were critical to the successes of all six
U.S. lunar landings.  He subsequently served as the Manager for the Space
Shuttle orbiter, directing the design, development, production and initial
flight testing of the orbiter.

    Cohen was made responsible for all engineering and research at the
Johnson Space Center following the successful completion of the Space Shuttle
orbital flight tests, assuming his present responsibilities as Director of the
Johnson Space Center in 1986.  In March of 1992 until March of 1993, he served
as Acting Deputy Administrator of NASA.

    Dan Goldin, the NASA Administrator, said of Cohen, "Aaron represents
all of the finest you could 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.

    "I know my fellow NASA employees join me in saying we will sorely miss
him and his wise counsel and advice.  Aaron can take great pride in his past
achievements as he now takes on the challenge of an academic career.  We all
wish him well as he returns to Texas A&M. I know his new career will be one
that is equally marked by great accomplishments and dedicated service," Goldin
said.

    Goldin announced that Cohen will serve as a Special Consultant to the
Administrator on human space flight as well as research and technology. "Even
though Aaron will be involved with his duties at Texas A&M, he has agreed to
continue to assist NASA in answering the challenges that lie ahead.  His
continuing involvement will allow us to take advantage of his tremendous
experience, knowledge and expertise.  Both Texas A&M and NASA can continue to
benefit from the involvement of one of NASA's finest managers and engineers,"
said Goldin.

    Dr.  Herbert H. Richardson, chancellor of the Texas A&M University
System and Dr. Kenneth L. Peddicord, interim dean of the College of
Engineering, expressed pleasure that Cohen's extensive experience with the U.S.
space program now would be applied to the University's programs. "As a leader
in the space program for more than 3 decades, his unparalleled scientific and
programmatic experience will be a gold mine for our students," Richardson said.
Pedicord noted that Cohen plans to develop multidisciplinary courses based on
his NASA background aimed at both undergraduate and graduate students, and
said, "we're thrilled that Mr. Cohen and his vast experiences are coming to the
faculty and students at Texas A&M."

    In announcing his plans Cohen said, "I am leaving with a great sense of
accomplishment, but also with an enormous feeling of nostalgia.  I have had the
privilege of working with the giants of our profession, and I have had the good
fortune to see future giants in the making.  I am confident our nation's future
space endeavors will be in good hands, and I look forward to helping Texas A&M
educate our nation's future engineers."

    Cohen's many honors include the highest award for senior Federal
executives, the Presidential Rank of Distinguished Executive (1982 and 1988)
and he has three times been the recipient of NASA's highest award, the
Distinguished Service Medal. He is a member of the National Academy of
Engineering, a Fellow of the American Astronautical Society and the American
Institute of Aeronautics and Astronautics, a Distinguished Alumnus of Texas
A&M, recipient of honorary doctorate degrees from Stevens Institute of
Technology and from the University of Houston-Clear Lake, and recipient of the
American Society of Mechanical Engineers Medal.

    Cohen received his Bachelor's degree in Mechanical Engineering from
Texas A&M in 1952, and his Master's degree in Applied Mathematics from Stevens
Institute of Technology in 1958.  He and his wife, Ruth, have three married
children and seven grand children.

- end -
     Source:NASA Spacelink    Modem:205-895-0028  Internet:192.149.89.61
=--=--=-END-=--=--=

=--=--=START=--=--= NASA Spacelink File Name:6_2_2_46_9.TXT

L-1 DAY LAUNCH WEATHER FORECAST

              LAUNCH WEATHER FORECAST FOR STS-51
                             L-1 Days



George H. Diller
NASA Kennedy Space Center


Synopsis: Strengthening high pressure will dominate.  Weak low altitude and
mid-level winds provide little movement for developing convective showers or
thunderstorms over land, however, offshore activity will move gradually
onshore.


At the opening of the launch window at 9:22 a.m. on Saturday forecast
conditions are:


Clouds:  scattered at 3,000 feet
         scattered at 25,000 feet
Visibility: 7 or miles or greater
Wind - Pad 39B: WSW/4-6 knots
Temperature:  84 degrees
Dewpoint:     70 degrees
Humidity:     60%
Precipitation: slight chance of showers offshore

Other weather concerns: possible chance of thunderstorm and
clouds extending over KSC area



Probability of launch weather violation on Saturday: 10%
                      tanking violation on Saturday:  5%

Chance of violation with 24 hour scrub turnaround: 10%
                         48 hour scrub turnaround: 10%



Cape Canaveral Forecast Facility
Department of the Air Force
7/16/93
     Source:NASA Spacelink    Modem:205-895-0028  Internet:192.149.89.61
=--=--=-END-=--=--=

=--=--=START=--=--= NASA Spacelink File Name:6_7_2_16_7.TXT

7/16/93:  HUBBLE SUPPORTS BLACK HOLE MODEL FOR ACTIVE GALAXIES

Paula Cleggett-Haleim
Headquarters, Washington, D.C.
July 16, 1993

Jim Elliott
Goddard Space Flight Center, Greenbelt, Md.

Ray Villard
Space Telescope Science Institute, Baltimore, Md.

RELEASE:  93-130

    A team of astronomers reports that recent NASA Hubble Space Telescope
(HST) observations of a class of active galaxies further support the theory
that they are fueled by a massive black hole at the center.

    The researchers say the HST results rule out vigorous star formation as
the alternative explanation for the mysterious power source behind quasars and
extremely bright galactic nuclei.

    "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," says Alexei V. Filippenko, Professor of Astronomy, University of
California at Berkeley. "The most likely alternative, then, is the standard
model in which the energy is provided by matter falling into a black hole."

    Seyfert galaxies are nearby galaxies with extremely bright central
regions that often obscure the much dimmer stars in the surrounding galaxy.
Quasars -- quasi stellar radio sources -- are among the most distant objects in
the universe and are visible from Earth only because they are so bright.

    Both types of objects, collectively referred to as active galactic
nuclei (AGN), give off prodigious amounts of energy.  Much of the radiation is
in the form of high-energy x-rays and gamma rays.

Convincing Observations

    Observations over the past 30 years have convinced most astronomers
that the only object capable of producing such tremendous amounts of energy in
a relatively small galactic core is a black hole.

    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 with
one another, releasing tremendous amounts of radiation.

    A competing explanation is the starburst hypothesis, which proposes
some active galaxies -- in particular so-called Seyfert galaxies and some
dimmer quasars -- are bright because of vigorous star formation at the center.
This starburst activity generates massive hot stars that evolve rapidly and
explode after a mere 10 million years.

    This model, championed by Roberto Terlevich of the Royal Greenwich
Observatory in Cambridge, England, predicts that light from the nucleus of an
active galaxy should show characteristics of light from very hot stars.  In
particular, it should show ultraviolet absorption lines -- specific wavelengths
in the ultraviolet part of the spectrum that are blocked or absorbed by cooler
gas in the atmospheres of the stars.

    "Terlevich's hypothesis was generally dismissed by astronomers, but we
felt it was conceivable that some of the least luminous active galaxies could
have enough stars in their nuclei to produce this amount of energy," Filippenko
says. "Among astronomers, there is a tendency to associate anything mysterious
with a black hole, but we thought it was important to test the hypothesis and
not jump on the black-hole bandwagon."

    The astronomers chose to use NGC 4395 to test the starburst hypothesis
because the region around the nucleus is nearly devoid of stars, which could
contaminate the spectra and make the findings ambiguous.

    Filippenko and his colleagues used the Faint Object Spectrograph aboard
the HST to make a 7-hour observation of the nucleus of NGC 4395.  They did not
detect any absorption lines that could be ascribed to stars in the nucleus.

    "We can say with confidence that there is no unambiguous evidence that
stellar processes are responsible for light emitted by the nucleus of this
galaxy," Filippenko says.

    In addition, an image of the galaxy obtained with HST's Planetary
Camera shows a galactic center at most 2 light years across -- less than half
the distance from the sun to the nearest star.

Starburst Hypothesis

    "This is smaller than all but the smallest star clusters, which are
extremely rare, " Filippenko says. "Although the size alone does not rule out
the possibility of a star cluster being responsible for the light, it makes
this unlikely." He concludes, "The starburst hypothesis doesn't work for this
nearby active galaxy, so it probably doesn't work for most others."

    The findings are reported in the June 20, 1993, issue of The
Astrophysical Journal by Filippenko, graduate student Luis C. Ho and California
Institute of Technology astronomer Wallace L.W. Sargent.

    Filippenko and Sargent identified NGC 4395 4 years ago as the least
luminous and nearest Seyfert galaxy known, based on its spectrum.  It is about
8 million light years away in the direction of the constellation Canes Venatici
(The Hunting Dogs).

    Seyfert galaxies, quasars and other AGNs are generally thought to
comprise only about one of every 100 known galaxies.  Based on a survey of more
than 500 galaxies over the past 10 years, Filippenko and Sargent think the
number may be closer to one in 10.

    Previous Hubble observations 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.

    Support for the research was provided by NASA through the Space
Telescope Science Institute and the National Science Foundation. The Hubble
Space Telescope is a project of international cooperation between NASA and the
European Space Agency.
     Source:NASA Spacelink    Modem:205-895-0028  Internet:192.149.89.61
=--=--=-END-=--=--=

=--=--=START=--=--= NASA Spacelink File Name:6_8_3_4_36.TXT

MAGELLAN STATUS REPORT FOR WEEK ENDING 7/16/93

Magellan Significant Events for Week Ending 7/16/93

1.  The Magellan Transition Experiment continues to go well after 52 days of
aerobraking in the Venus atmosphere.  All subsystems are reported to be
nominal.  The apoapsis has been reduced below 2700 km (from its original 8460
km).

2.  Atmospheric density has continued to decrease since COTM9 two weeks ago, so
COTM10, a 1/2 down maneuver, was performed early Thursday to keep the orbit
change on track for achieving a 102-minute orbit on July 27th.


Magellan Significant Events for Next Week

1.  The periapsis altitude will drift upward until late July, then downward.
Another full down COTM is planned for Tuesday.

2.  The "end game" phase of aerobraking is now targeted for the period between
July 27 and August 8, with a final orbit 200 km and 650 km from the surface of
Venus.


COTM = Corridor Orbit Trim Maneuver
     Source:NASA Spacelink    Modem:205-895-0028  Internet:192.149.89.61
=--=--=-END-=--=--=

=--=--=START=--=--= NASA Spacelink File Name:9_10_15_2.TXT

 NOTE: This file is too large {36299 bytes} for inclusion in this collection.
    The first line of the file:

THE EXPLORATION OF MARS

     Source:NASA Spacelink    Modem:205-895-0028  Internet:192.149.89.61
=--=--=-END-=--=--=

=--=--=START=--=--= NASA Spacelink File Name:9_11_19_5.TXT

STS-51 PRE-LAUNCH ELEMENTS


STS-51
1 00051U          93198.60748674  .00044522  00000-0  13742-3 0    19
2 00051  28.4662 327.4431 0004344 291.3491  68.6685 15.91099027    28

Satellite: STS-51
Catalog number: 00051
Epoch time:      93198.60748674   =    (17 JUL 93   14:34:46.85 UTC)
Element set:     001
Inclination:       28.4662 deg
RA of node:       327.4431 deg           Space Shuttle Flight STS-51
Eccentricity:     .0004344              Prelaunch Element set JSC-001
Arg of perigee:   291.3491 deg          Launch:  17 JUL 93  13:22 UTC
Mean anomaly:      68.6685 deg
Mean motion:   15.91099027 rev/day              G. L. Carman
Decay rate:     4.4522e-04 rev/day~2      NASA Johnson Space Center
Epoch rev:               2
Checksum:              290

G.L.CARMAN
     Source:NASA Spacelink    Modem:205-895-0028  Internet:192.149.89.61
=--=--=-END-=--=--=

=--=END OF COLLECTION---COLLECTED 10 FILES---COMPLETED 21:07:33=--=