home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Space & Astronomy
/
Space and Astronomy (October 1993).iso
/
pc
/
text
/
daily_1
/
930318.dfc
< prev
next >
Wrap
Text File
|
1993-03-20
|
34KB
|
664 lines
"930318.DFC" (32656 bytes) was created on 03-19-93
18-Mar-93 Daily File Collection
These files were added or updated between 17-Mar-93 at 21:00:00 {Central}
and 18-Mar-93 at 21:00:33.
=--=--=START=--=--= NASA Spacelink File Name:930318.REL
PRELIMINARY RESULTS FROM ATLAS 1 (STS-45)
NASA Facts
National Aeronautics and Space Administration
Washington, D.C. 20546
Preliminary Results from ATLAS 1
The first Atmospheric Laboratory for Applications and Science (ATLAS 1)
conducted 14 investigations in atmospheric science, solar science, space plasma
physics and astronomy. The 13 instruments were carried aboard two Spacelab
pallets or mounted on the payload bay walls of the Space Shuttle Atlantis,
which was launched March 24, 1992 and landed April 4, 1992.
The data from these investigations will be used in several ways. The
six ATLAS core instruments and the co-manifested Shuttle Solar Backscatter
Ultraviolet Experiment (SSBUV), will be reflown periodically to provide
"snapshots" the Earth's atmosphere and the Sun at different points of the 11-
year solar cycle.
ATLAS 1 obtained substantial volumes of data that will help scientists
better understand the chemistry of the atmosphere, the energy output of the
sun, the behavior of high-energy particles as they reach the atmosphere and the
structure of the universe.
In addition, data from several ATLAS 1 instruments, which are precisely
calibrated before and after flight, will be compared to observations from
similar instruments aboard free-flying satellites. This will help insure the
accuracy of a large portion of the data that is the ultimate product of NASA's
Mission to Planet Earth, a comprehensive research program that takes advantage
of the perspective from space to study the Earth as a global environment
system.
Though data analysis continues, some preliminary results are available.
Data will continue to be refined and results published in scientific journals.
A special section of Geophysical Research Letters, a journal of the American
Geophysical Union, devoted entirely to ATLAS 1 results, is scheduled for
publication in spring 1993.
Atmospheric Science
Atmospheric Trace Molecule Spectroscopy (ATMOS):
Showed increases in hydrogen fluoride and hydrogen chlorideQcompounds involved
in ozone depletionQfrom the instrument's 1985 flight aboard Spacelab 3. These
increases are consistent with predictions of computer models and with
measurements of surface concentrations of chlorofluorocarbons, which are the
sources of the chlorine and fluorine in the stratosphere.
ATMOS obtained more than 9,300 spectra in 53 orbital sunrises and 41
sunsets. The instrument made 30 coincident measurements with the HALOE
instrument aboard the Upper Atmosphere Research Satellite (UARS), 24 coincident
measurements with UARS' CLAES instrument and 14 coincident measurements with
the SAGE II instrument aboard the Earth Radiation Budget Satellite (ERBS). The
formal comparison and analysis of data between the ATMOS and UARS science teams
will begin in 1993.
Atmospheric Lyman-Alpha Emissions (ALAE):
Expanded our knowledge about how chemicals mix in the regions above our
atmosphere by improving upon previous measurements of hydrogen and deuterium.
ALAE observed deuterium as far down as approximately 50 miles (80
kilometers), the bottom of the atmospheric region known as the thermosphere.
This measurement represents an important advance over ALAE's measurements on
Spacelab 1 in 1983, in which atomic deuterium could not be detected below
approximately 70 miles (110 km). ALAE also obtained measurements of hydrogen
and deuterium in the exosphere and interplanetary medium.
The results from the Earth's upper atmosphere can also be compared to
similar measurements made in the atmospheres of Venus and Mars to help us
better understand the differences between the atmospheres of the planets.
Grille Spectrometer (Grille): Observed 10 trace atmospheric gases, including
carbon dioxide, ozone and chemicals involved in stratospheric ozone depletion.
Initial analysis shows an increase in hydrogen chloride from the mid-1980s,
compared to ATMOS data from Spacelab 3. GRILLE obtained 89 observations
ranging from 1 degree South to 33 degrees South. An additional measurement was
made at 29 degrees North on the ninth (extra) day of the mission. Data also
were compared with those from Grille's first flight, aboard Spacelab 1 in 1983.
Imaging Spectrometic Observatory (ISO):
Obtained the first complete spectral map of the ionosphere, thermosphere and
mesosphere (altitudes between 40 and 240 miles). ISO also made the first
space-based measurement of the hydroxyl radical (OH, a key intermediate of the
chemistry affecting ozone levels in the mesosphere and stratosphere) between
approximately 40 and 50 miles (70-80 km) Together with measurements from ALAE,
MAS, ATMOS, and GRILLE, these data will form a comprehensive set of mesospheric
chemistry data that can be used to validate computer models.
ISO also made the first comprehensive spectral survey of mesospheric
airglow, the faint glow that emanates from chemical reactions in the upper
atmosphere. The airglow data can be used to help evaluate computer models of
the atmosphere. ISO also made the first dayglow profiles of an electronically
excited form of atomic nitrogen, which may improve our understanding of nitric
oxide in the thermosphere and the critical role it plays in the chemistry in
the upper atmosphere.
Millimeter-Wave Atmospheric Science (MAS):
Refined our knowledge of the atmosphere with measurements of ozone, chlorine
monoxide and water vapor that were consistent with existing models and previous
observations. Day-night, latitudinal and vertical variations in ozone and
water vapor were as expected. The MAS data show significant variations in
ozone across longtitudes at approximately 60 degrees latitude and 18 miles (30
km) altitude. This is consistent with data from the Total Ozone Mapping
Spectrometer (TOMS) aboard NASA's Nimbus 7 satellite.
The MAS measurements are also being compared to ground- based microwave
measurements to improve validation and interpretation. MAS measurements will
be compared to those from instruments aboard the Upper Atmosphere Research
Satellite (UARS) to better assess the MAS and UARS measurements.
Shuttle Solar Backcatter Ultraviolet Experiment (SSBUV):
Indicated, through comparisons of SSBUV data with the Solar Backscatter
Ultraviolet Experiment (SBUV-2) instrument aboard the NOAA-11 weather
satellite, that the SBUV-2 instrument has continued to degrade at its shortest
wavelengths as expected. Subsequent analysis will allow science teams to
compare SSBUV's ozone data with NOAA-11's and refine the latter's data.
Other results indicate that SSBUV's sensitivity over most of its
wavelengths was comparable to that seen in SSBUV's previous flight (August
1991), and that comparisons of solar measurements between these two flights was
quite good at most wavelengths.
SSBUV obtained ozone profiles and total ozone amounts during 34 orbits.
For six additional orbits, the instrument observed upper stratospheric ozone
distributions with a higher resolution across Earth's latitudes. The
instrument also obtained solar ultraviolet measurements on seven orbits, and
there were four in-flight calibrations to assess instrument performance.
Solar Science
Active Cavity Radiometer Irradiance Monintor (ACRIM) and the
Measurement of the Solar Constant (SOLCON):
Obtained data on the solar constant that are still being analyzed and compared
to several similar instruments, including the ACRIM instrument onboard UARS and
to the Earth Radiation Budget Experiment (ERBE) onboard the Earth Radiation
Budget Satellite (ERBS). SOLCON data show strong evidence for solar variation
during the mission (higher solar levels during the first and fourth solar
pointing period than the second and third). The expected correlation between
total solar output and the number of sunspots was observed.
Solar Spectrum Measurement (SOLSPEC) and the Solar Ultraviolet
Spectral Irradiance Monitor (SUSIM):
Obtained measurements of the sun's ultraviolet energy. Results are being
compared with those obtained from the previous flights of these instruments
aboard Spacelab 1 and Spacelab 2, respectively. Preliminary comparisons
indicate relatively good agreement between the two flights for both
instruments.
Once final analysis of the SUSIM data are completed, the results will
be compared with the SUSIM instrument flying aboard UARS. These highly
calibrated instruments are an important check on solar ultraviolet data because
the harsh environment of space significantly degrades instruments on
free-flying satellites. While these instruments are designed with onboard
calibration lamps to correct for instrument degradation, the confidence gained
by having an independent instrument available for comparison is critical, given
the importance of ultraviolet radiation in creating and destroying ozone.
Space Plasma Physics
Atmospheric Emissions Photometric Imaging (AEPI):
Succeeded in several different areas. By observing the formation and changes
in airglow (high- energy particles) around the shuttle, AEPI will help answer
questions about the energetics and dynamics of the mesosphere. These
measurements are important in their own right and also will better define the
science objectives of the proposed Thermosphere-Ionosphere-Mesosphere
Energetics and Dynamics (TIMED) mission.
AEPI also observed the artificial auroras created by the SEPAC
instrument. By knowing the energy levels and electric currents of these beams,
and then observing the beams' behavior and lifetimes, the AEPI team will be
able to better understand how natural aurorae behave and the structure of the
Earth's magnetic field. The AEPI-SEPAC experiments also proved the technology
of beam formation and the detection of subsequent aurora.
Energetic Neutral Atom Precipitation (ENAP):
Using the ISO instrument, studied emissions from neutral atoms (not
electrically charged) atoms that reached the upper atmosphere. Emissions from
several chemicals were observed, and quantitative information on the magnitude
of these emissions was obtained. These data are particularly important for
understanding emissions at low- to mid-magnetic latitudes. Thermospheric
modelers will use the data to better understand the effect of neutral atom
precipitation on the chemistry of thermosphere and ionsphere.
Space Experiments with Particle Accelerators (SEPAC):
Created and observed several artificial auroras, allowing scientists to observe
the structure of the Earth's magnetic field. Together, data from SEPAC and
AEPI showed the size and intensity of the artificial auroras and determined the
cause of their shape. Correlative measurements made from the ground in Peru
detected disturbances associated with the SEPAC plasma contactor beam. The
SEPAC investigation will provide significant amounts of data that will help us
better understand the structure of the Earth's magnetic field and the behavior
of high-energy particles from space as they reach the field.
Astronomy
Far Ultraviolet Space Telescope (FAUST):
Observed 22 fields and detected 4,976 objects. Data anlyzed to date include
images from the north galactic pole and the galactic and extragalactic
background, as well as of the broad structural characteristics of galaxies.
Data on far ultraviolet emissions of the Earth were also obtained, as was
information about the magnitude of a potential Shuttle effect on astronomical
observations. Astronomical data have been compared to that from other
spacecraft for particular objects; a good correlation between the flux observed
by FAUST and that from the International Ultraviolet Explorer (IUE) satellite
was obtained.
FAUST data also indicated that the orbital night at ATLAS 1's
approximately 180-mile altitude becomes sufficiently dark that astronomical and
geophysical observations can be made to low light levels. A faint far
ultraviolet glow seen when looking down at the Earth has been shown to be of
terrestrial origin and not due to shuttle glow.
March 1993
Source:NASA Spacelink Modem:205-895-0028 Internet:192.149.89.61
=--=--=-END-=--=--=
=--=--=START=--=--= NASA Spacelink File Name:930318.SKD
DAILY NEWS/TV SKED 3/18/93
Daily News
Thursday, March 18, 1993
Two Independence Square,
Washington, D.C..
Audio Service: 202/358-3014
% STS-55 Status;
% Gravity Wave Search
% STS-56 Update
* * * * * * * * * * * * * * * *
Technicians at the Kennedy Space Center are working to prepare orbiter Columbia
for its March 21 launch. Workers will resume aft main engine compartment
closeouts and inspections. They will also resume avionics bay closeouts and
will begin countdown later today. Space Shuttle mission STS-55 is scheduled to
last 8 days and have a crew of 7. STS- 55's primary payload is Spacelab D2 and
is the second mission basically dedicated to Germany research.
Beginning tomorrow at 9:00 am EST, NASA TV will carry the STS-55 L-2 Countdown
Status briefing. The briefing will originate from the Kennedy Space Center.
* * * * * * * * * * * * * * * *
Three interplanetary spacecraft, headed for Mars, Jupiter and over the poles of
the sun, may soon prove the existence of elusive waves in the universe's
gravitational field by bobbing on ripples in space.
Having never been directly detected, these waves were predicted decades ago in
Einstein's theory of relativity. The waves are believed to be made by
supernova explosions, collapsing black holes and other catastrophic events.
The spacecraft, on their way to seperate destinations in the solar system, are
NASA's Mars Observer, Galileo and the European Space Agency's Ulysses
spacecraft. The joint NASA-ESA experiment will run from March 21 to April 11.
This will mark the first time three spacecraft will make observations at the
same time, greatly increasing the reliability of any detection.
Successful detection of gravitational waves can open up an entirely new kind of
astronomy. "Gravitational wave research is now in the hands of physicists.
Once signals are detected, the astronomers will be beating down the doors, "
says Dr. Robert Stachnik, Wave Program Scientist in NASA's Astrophysics
Division.
* * * * * * * * * * * * * * * *
The STS-56 Preflight Briefing is scheduled to start tomorrow at 9:30 am EST
with a mission overview and will continue most of the day. The briefing will
be carried live on NASA television and will have question and answers from
participating NASA centers.
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. Live indicates a program is transmitted live.
Thursday, March 18, 1993
12:00 pm A Dive Into Space
12:15 pm Replay of STS-55 Countdown Briefing
12:30 pm Best of NASA Today: Technology 2001
1:00 pm Apollo 15: In the Mountains of the Moon
1:30 pm Zero-G and Space Suits
2:00 pm Starfinder #19
2:30 pm Voyager 2/Saturn Encounter
3:00 pm TQM 59
4:15 pm Replay of STS-55 Countdown Briefing
Friday, March 19, 1993
9:00 am STS-55 Countdown Status L-2 (KSC)
9:30 am STS-56 Mission Overview (JSC)
10:30 am Atmospheric Laboratory for Applications and Science (MSFC)
11:35 am SPARTAN (JSC)
12:10 pm Shuttle Amateur Radio Experiments (JSC)
2:00 pm DED Experiments Overview (JSC)
3:00 pm STS-56 Crew Briefing (JSC)
NASA Select 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:6_2_18_5.TXT
NOTE: This file is too large {25271 bytes} for inclusion in this collection.
The first line of the file:
- Current Two-Line Element Sets #161 -
Source:NASA Spacelink Modem:205-895-0028 Internet:192.149.89.61
=--=--=-END-=--=--=
=--=--=START=--=--= NASA Spacelink File Name:6_2_2_35_18.TXT
PRELIMINARY RESULTS FROM ATLAS 1 (STS-45)
NASA Facts
National Aeronautics and Space Administration
Washington, D.C. 20546
Preliminary Results from ATLAS 1
The first Atmospheric Laboratory for Applications and Science (ATLAS 1)
conducted 14 investigations in atmospheric science, solar science, space plasma
physics and astronomy. The 13 instruments were carried aboard two Spacelab
pallets or mounted on the payload bay walls of the Space Shuttle Atlantis,
which was launched March 24, 1992 and landed April 4, 1992.
The data from these investigations will be used in several ways. The
six ATLAS core instruments and the co-manifested Shuttle Solar Backscatter
Ultraviolet Experiment (SSBUV), will be reflown periodically to provide
"snapshots" the Earth's atmosphere and the Sun at different points of the 11-
year solar cycle.
ATLAS 1 obtained substantial volumes of data that will help scientists
better understand the chemistry of the atmosphere, the energy output of the
sun, the behavior of high-energy particles as they reach the atmosphere and the
structure of the universe.
In addition, data from several ATLAS 1 instruments, which are precisely
calibrated before and after flight, will be compared to observations from
similar instruments aboard free-flying satellites. This will help insure the
accuracy of a large portion of the data that is the ultimate product of NASA's
Mission to Planet Earth, a comprehensive research program that takes advantage
of the perspective from space to study the Earth as a global environment
system.
Though data analysis continues, some preliminary results are available.
Data will continue to be refined and results published in scientific journals.
A special section of Geophysical Research Letters, a journal of the American
Geophysical Union, devoted entirely to ATLAS 1 results, is scheduled for
publication in spring 1993.
Atmospheric Science
Atmospheric Trace Molecule Spectroscopy (ATMOS):
Showed increases in hydrogen fluoride and hydrogen chlorideQcompounds involved
in ozone depletionQfrom the instrument's 1985 flight aboard Spacelab 3. These
increases are consistent with predictions of computer models and with
measurements of surface concentrations of chlorofluorocarbons, which are the
sources of the chlorine and fluorine in the stratosphere.
ATMOS obtained more than 9,300 spectra in 53 orbital sunrises and 41
sunsets. The instrument made 30 coincident measurements with the HALOE
instrument aboard the Upper Atmosphere Research Satellite (UARS), 24 coincident
measurements with UARS' CLAES instrument and 14 coincident measurements with
the SAGE II instrument aboard the Earth Radiation Budget Satellite (ERBS). The
formal comparison and analysis of data between the ATMOS and UARS science teams
will begin in 1993.
Atmospheric Lyman-Alpha Emissions (ALAE):
Expanded our knowledge about how chemicals mix in the regions above our
atmosphere by improving upon previous measurements of hydrogen and deuterium.
ALAE observed deuterium as far down as approximately 50 miles (80
kilometers), the bottom of the atmospheric region known as the thermosphere.
This measurement represents an important advance over ALAE's measurements on
Spacelab 1 in 1983, in which atomic deuterium could not be detected below
approximately 70 miles (110 km). ALAE also obtained measurements of hydrogen
and deuterium in the exosphere and interplanetary medium.
The results from the Earth's upper atmosphere can also be compared to
similar measurements made in the atmospheres of Venus and Mars to help us
better understand the differences between the atmospheres of the planets.
Grille Spectrometer (Grille): Observed 10 trace atmospheric gases, including
carbon dioxide, ozone and chemicals involved in stratospheric ozone depletion.
Initial analysis shows an increase in hydrogen chloride from the mid-1980s,
compared to ATMOS data from Spacelab 3. GRILLE obtained 89 observations
ranging from 1 degree South to 33 degrees South. An additional measurement was
made at 29 degrees North on the ninth (extra) day of the mission. Data also
were compared with those from Grille's first flight, aboard Spacelab 1 in 1983.
Imaging Spectrometic Observatory (ISO):
Obtained the first complete spectral map of the ionosphere, thermosphere and
mesosphere (altitudes between 40 and 240 miles). ISO also made the first
space-based measurement of the hydroxyl radical (OH, a key intermediate of the
chemistry affecting ozone levels in the mesosphere and stratosphere) between
approximately 40 and 50 miles (70-80 km) Together with measurements from ALAE,
MAS, ATMOS, and GRILLE, these data will form a comprehensive set of mesospheric
chemistry data that can be used to validate computer models.
ISO also made the first comprehensive spectral survey of mesospheric
airglow, the faint glow that emanates from chemical reactions in the upper
atmosphere. The airglow data can be used to help evaluate computer models of
the atmosphere. ISO also made the first dayglow profiles of an electronically
excited form of atomic nitrogen, which may improve our understanding of nitric
oxide in the thermosphere and the critical role it plays in the chemistry in
the upper atmosphere.
Millimeter-Wave Atmospheric Science (MAS):
Refined our knowledge of the atmosphere with measurements of ozone, chlorine
monoxide and water vapor that were consistent with existing models and previous
observations. Day-night, latitudinal and vertical variations in ozone and
water vapor were as expected. The MAS data show significant variations in
ozone across longtitudes at approximately 60 degrees latitude and 18 miles (30
km) altitude. This is consistent with data from the Total Ozone Mapping
Spectrometer (TOMS) aboard NASA's Nimbus 7 satellite.
The MAS measurements are also being compared to ground- based microwave
measurements to improve validation and interpretation. MAS measurements will
be compared to those from instruments aboard the Upper Atmosphere Research
Satellite (UARS) to better assess the MAS and UARS measurements.
Shuttle Solar Backcatter Ultraviolet Experiment (SSBUV):
Indicated, through comparisons of SSBUV data with the Solar Backscatter
Ultraviolet Experiment (SBUV-2) instrument aboard the NOAA-11 weather
satellite, that the SBUV-2 instrument has continued to degrade at its shortest
wavelengths as expected. Subsequent analysis will allow science teams to
compare SSBUV's ozone data with NOAA-11's and refine the latter's data.
Other results indicate that SSBUV's sensitivity over most of its
wavelengths was comparable to that seen in SSBUV's previous flight (August
1991), and that comparisons of solar measurements between these two flights was
quite good at most wavelengths.
SSBUV obtained ozone profiles and total ozone amounts during 34 orbits.
For six additional orbits, the instrument observed upper stratospheric ozone
distributions with a higher resolution across Earth's latitudes. The
instrument also obtained solar ultraviolet measurements on seven orbits, and
there were four in-flight calibrations to assess instrument performance.
Solar Science
Active Cavity Radiometer Irradiance Monintor (ACRIM) and the
Measurement of the Solar Constant (SOLCON):
Obtained data on the solar constant that are still being analyzed and compared
to several similar instruments, including the ACRIM instrument onboard UARS and
to the Earth Radiation Budget Experiment (ERBE) onboard the Earth Radiation
Budget Satellite (ERBS). SOLCON data show strong evidence for solar variation
during the mission (higher solar levels during the first and fourth solar
pointing period than the second and third). The expected correlation between
total solar output and the number of sunspots was observed.
Solar Spectrum Measurement (SOLSPEC) and the Solar Ultraviolet
Spectral Irradiance Monitor (SUSIM):
Obtained measurements of the sun's ultraviolet energy. Results are being
compared with those obtained from the previous flights of these instruments
aboard Spacelab 1 and Spacelab 2, respectively. Preliminary comparisons
indicate relatively good agreement between the two flights for both
instruments.
Once final analysis of the SUSIM data are completed, the results will
be compared with the SUSIM instrument flying aboard UARS. These highly
calibrated instruments are an important check on solar ultraviolet data because
the harsh environment of space significantly degrades instruments on
free-flying satellites. While these instruments are designed with onboard
calibration lamps to correct for instrument degradation, the confidence gained
by having an independent instrument available for comparison is critical, given
the importance of ultraviolet radiation in creating and destroying ozone.
Space Plasma Physics
Atmospheric Emissions Photometric Imaging (AEPI):
Succeeded in several different areas. By observing the formation and changes
in airglow (high- energy particles) around the shuttle, AEPI will help answer
questions about the energetics and dynamics of the mesosphere. These
measurements are important in their own right and also will better define the
science objectives of the proposed Thermosphere-Ionosphere-Mesosphere
Energetics and Dynamics (TIMED) mission.
AEPI also observed the artificial auroras created by the SEPAC
instrument. By knowing the energy levels and electric currents of these beams,
and then observing the beams' behavior and lifetimes, the AEPI team will be
able to better understand how natural aurorae behave and the structure of the
Earth's magnetic field. The AEPI-SEPAC experiments also proved the technology
of beam formation and the detection of subsequent aurora.
Energetic Neutral Atom Precipitation (ENAP):
Using the ISO instrument, studied emissions from neutral atoms (not
electrically charged) atoms that reached the upper atmosphere. Emissions from
several chemicals were observed, and quantitative information on the magnitude
of these emissions was obtained. These data are particularly important for
understanding emissions at low- to mid-magnetic latitudes. Thermospheric
modelers will use the data to better understand the effect of neutral atom
precipitation on the chemistry of thermosphere and ionsphere.
Space Experiments with Particle Accelerators (SEPAC):
Created and observed several artificial auroras, allowing scientists to observe
the structure of the Earth's magnetic field. Together, data from SEPAC and
AEPI showed the size and intensity of the artificial auroras and determined the
cause of their shape. Correlative measurements made from the ground in Peru
detected disturbances associated with the SEPAC plasma contactor beam. The
SEPAC investigation will provide significant amounts of data that will help us
better understand the structure of the Earth's magnetic field and the behavior
of high-energy particles from space as they reach the field.
Astronomy
Far Ultraviolet Space Telescope (FAUST):
Observed 22 fields and detected 4,976 objects. Data anlyzed to date include
images from the north galactic pole and the galactic and extragalactic
background, as well as of the broad structural characteristics of galaxies.
Data on far ultraviolet emissions of the Earth were also obtained, as was
information about the magnitude of a potential Shuttle effect on astronomical
observations. Astronomical data have been compared to that from other
spacecraft for particular objects; a good correlation between the flux observed
by FAUST and that from the International Ultraviolet Explorer (IUE) satellite
was obtained.
FAUST data also indicated that the orbital night at ATLAS 1's
approximately 180-mile altitude becomes sufficiently dark that astronomical and
geophysical observations can be made to low light levels. A faint far
ultraviolet glow seen when looking down at the Earth has been shown to be of
terrestrial origin and not due to shuttle glow.
March 1993
Source:NASA Spacelink Modem:205-895-0028 Internet:192.149.89.61
=--=--=-END-=--=--=
=--=--=START=--=--= NASA Spacelink File Name:6_2_2_43_7.TXT
STS-55 FLIGHT DAY 1 STATE VECTOR (PREDICTED) ON ORBIT OPERATIONS
(Posted 03/18/93 by Roger Simpson)
The following vector for the flight of STS-55 is provided by NASA Johnson Space
Center, Flight Design and Dynamics Division for use in ground track plotting
programs. The vector represents the predictied trajectory of Columbia during
on orbit operations, after the OMS-2 maneuver.
THE VECTOR ASSUMES AN ON TIME LAUNCH.
Lift off Time : 1993/080/14:52:00.000
Lift off Date : 03/21/93
Vector Time (GMT) : 080/15:35:00.000
Vector Time (MET) : 000/00:43:00.000
Orbit Count : 1
Weight : 244237.0 LBS
Drag Coefficient : 2.00
Drag Area : 2750.0 SQ FT
M50 Elements Keplerian Elements
----------------------- --------------------------
X = -7282180.4 FT A = 3608.0505 NM
Y = 18545075.2 FT E = 0.000522
Z = -9120618.7 FT I (M50) = 28.26316 DEG
Xdot = -21900.038934 FT/S Wp (M50) = 258.54411 DEG
Ydot = -11418.251720 FT/S RAAN (M50) = 233.06347 DEG
Zdot = -5721.930488 FT/S / N (True) = 342.98110 DEG
Anomalies \ M (Mean) = 342.99858 DEG
Ha = 162.4038 NM
Hp = 160.0045 NM
Mean of 1950 (M50) : Inertial, right-handed Cartesian system whose
Coordinate System origin is the center of the earth. The epoch
is the beginning of the Besselian year 1950.
X axis: Mean vernal equinox of epoch
Z axis: Earth's mean rotational axis of epoch
Y axis: Completes right-hand system
A: Semi-major axis
E: Eccentricity N: True anomaly
I: Inclination M: Mean anomaly
Wp: Argument of perigee Ha: Height of apogee
RAAN: Right ascension of ascending node Hp: Height of perigee
POSTED BY RSIMPSON AT VMSPFHOU ON VMSPFHOU.VMBOARDS:PAONEWS
Source:NASA Spacelink Modem:205-895-0028 Internet:192.149.89.61
=--=--=-END-=--=--=
=--=--=START=--=--= NASA Spacelink File Name:6_8_4_9_30.TXT
MARS OBSERVER MISSION STATUS March 18, 1993
The Mars Observer spacecraft completed its third trajectory correction
maneuver (TCM-3) today at 11 a.m. Pacific Standard Time, setting the stage for
approach and capture in Mars orbit on Aug. 24, 1993.
The spacecraft fired four of its small 22-Newton thrusters to achieve the
desired change in velocity of 0.46 meters (1.5 feet) per second. Preliminary
engineering data indicated that the 17-second maneuver was successfully
completed. If necessary, a fourth TCM will be performed 20 days before orbit
insertion.
All spacecraft subsystems and instrument payload are performing well in the
outer cruise configuration. Uplink and downlink communications are being
performed via the high-gain antenna.
Since activation of the high-gain antenna in early January, JPL has been
conducting a Ka-band communications link experiment with the Mars Observer
spacecraft. The experiment will evaluate communications capabilities using
shorter, 9-millimeter-long wavelengths rather than the 3.5-centimeter
wavelengths (X-band) that are currently used. The experiment is the first of
its kind and was made possible with advanced technology deployed at the
Goldstone 34-meter research antenna. Early results have been excellent and the
spacecraft will be periodically tracked at Ka- band throughout the mission.
The experiment is sponsored by NASA's Office of Space Communications and is
aimed at advancing technology for future, low-cost planetary exploration
missions.
Today Mars Observer is about 30 million kilometers (18 million miles) from
Mars, traveling at a velocity of about 11,000 kilometers per hour (7,500 miles
per hour) with respect to Mars. One-way light time to Earth is about 7.5
minutes (444 seconds).
Source:NASA Spacelink Modem:205-895-0028 Internet:192.149.89.61
=--=--=-END-=--=--=
=--=END OF COLLECTION---COLLECTED 7 FILES---COMPLETED 21:13:05=--=
