Дата: 08 апреля 1998 (1998-04-08)
От: Alexander Bondugin
Тема: Mars Global Surveyor Update - April 4, 1998
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Mars Global Surveyor
Saturday Update on Targeted Observations
04-APR-98 10:00 AM PST
Mars Global Surveyor made its first attempt to target a specific location on
the surface of Mars yesterday and missed the target very slightly. The site
of the Viking Lander 1 was the first target in the up coming set of four
that will include Viking Lander 2, Mars Pathfinder and the Cydonia region.
Global Surveyor came rather close, but the landing site was about 150 meters
(500 feet) to the west of the edge of the long, narrow image that was to
contain it. The image was well centered in the north to south direction. The
width of the image was slightly greater than 5 km (3 miles). The flight team
will continue its analysis of the targeting performance.
The sequence of events for the imaging of Cydonia was loaded on board the
spacecraft yesterday afternoon. The detailed commands to control the imaging
will be loaded in about 2 hours after the latest orbit determination has
been completed.
04-APR-98 4:00 PM PST
The Mars Global Surveyor flight team and camera operators may have been
successful in placing the site of the Viking Lander 2 within the field of
view of the MGS Mars Orbiter Camera on the second of four attempts to image
sites of interest on the surface of Mars. Like the atmospheric conditions in
Pasadena, CA, today, Utopia Planitia, the location of the Viking Lander 2,
was heavily overcast when the image was recorded shortly in early afternoon,
Pacific time, yesterday. The Mars Orbiter Camera team reports that because
of the surface obscuration, the location of the image with respect to
surface features is problematic. It is believed, however, that the
Viking-era landing location and one of its more recently estimated locations
are within the lower portion of the image. Knowledge of the Viking Lander 2
site is the least well established of the targets that Global Surveyor is
attempting to photograph. Analysis of the results of these first images will
help the project team with the future imaging attempts.
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=SANA=
Дата: 08 апреля 1998 (1998-04-08)
От: Alexander Bondugin
Тема: SJI's Sky and Space Update - April 1, 1998
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SAN JUAN INSTITUTE'S SKY AND SPACE UPDATE
Summary information about the night sky and recent findings and events
in solar system exploration and science. Updated every 2 weeks.
LAST UPDATED: WED. APR. 1, 1998
Prepared by: Dr. Bruce Betts and Andre Bormanis
OBJECTS TO LOOK FOR IN THE NIGHT SKY (MID-NORTHERN LATITUDES)
VENUS is visible in the low east-southeast in the pre-dawn sky, looking
like an extremely bright star.
JUPITER lies to the lower left of Venus shortly before dawn.
THE MOON
First Quarter Moon occurs Apr. 3 at 12:18 p.m. PST (UT - 8 hours).
Full Moon occurs Apr. 11 at 3:23 p.m. PDT (UT - 7 hours). This month's
full Moon is called the Grass Moon or Egg Moon.
PLANETARY SPACECRAFT UPDATE
MARS GLOBAL SURVEYOR: NASA's Mars Global Surveyor (MGS) spacecraft has
begun a summer-long set of scientific observations of the red planet from an
interim elliptical orbit. MGS has been taking science observations
periodically over the last several months, but the spacecraft was also going
through a series of aerobraking maneuvers: dipping into the upper atmosphere
to adjust its orbit. Aerobraking will be suspended until September, and will
then continue until March 1999, when the spacecraft will be in a final,
circular orbit for its prime mapping mission. Observations that will be
attempted between now and September include high resolution imaging of the
Viking and Pathfinder landing sites. For more information on the MGS
mission including already released data, see http://mars.jpl.nasa.gov/mgs/
EQUATOR-S: The Max Planck Institute in Germany launched the EQUATOR-S
spacecraft on Dec. 2 of last year. The main mission of Equator-S is to
examine how the solar wind interacts with the Earth's magnetic field,
particularly in equatorial latitudes. Earth's magnetic field protects us
from the harmful particles and radiation constantly generated by the Sun.
Equator-S was launched as a "piggy-back" payload on an Ariane-4 rocket
carrying a communications satellite to geostationary transfer orbit.
EXTRA-SOLAR PLANET UPDATE
In recent years, astronomers have detected a number of planets orbiting
other stars. The Sky & Space Update will inform its readers of new
extra-solar planets as they are discovered.
To date, nine planets, ranging in mass from roughly half the mass of
Jupiter to ten times the mass of Jupiter, are thought to have been detected
orbiting nearby, Sun-like stars. A number of additional, more massive
objects have also been observed, but some of these may be brown dwarf stars,
not planets.
The new planets have not been observed directly. The existence of some
of the planets has been inferred by the slight pull they exert on their
parent stars, which causes the star to trace out a tiny circular orbit in
rhythm with the orbiting planet.
This wobbling motion can be detected by looking at a planet-girded
star's light spectrum. The spectral lines of the star shift back and forth
as the star wobbles. The period of the spectral shifting gives the period
of the planet's orbit, which can then be used to calculate how far the
planet is from its star. The amplitude of the shift can be used to
calculate the planet's minimum mass.
A number of the known extra-solar planets have very tight orbits,
circling their stars closer than Mercury orbits our Sun. At least one of
the planets orbits its star at a distance where liquid water could possibly
exist on the surface of a terrestrial planet. It's conceivable that this
gas giant planet could have large moons, like our own Jupiter. If one or
more of these putative moons has an atmosphere, liquid water -- and thus
life -- would have a chance of existing there.
For more information on the search for extra-solar planets, visit
http://cannon.sfsu.edu/~williams/planetsearch.
THESE WEEKS IN SPACE HISTORY
APR. 3, 1966: The Soviet spacecraft Luna 10 became the first spacecraft
to orbit the Moon.
APR. 12, 1961: Soviet cosmonaut Yuri Gagarin became the first human to
travel in space, making one complete orbit of the Earth.
APR. 13, 1970: An oxygen tank explosion aboard the U.S. Apollo 13
spacecraft threatened the lives of the third crew of astronauts headed for a
Moon landing.
RANDOM SPACE FACT
If all of the particles that make up Saturn's rings were gathered
together, they would form a sphere about 120 miles in diameter, roughly the
size of Saturn's seventh largest moon, Mimas.
**********************************************************************
The San Juan Institute (SJI) is a non-profit corporation headquartered
in San Juan Capistrano, CA with divisions there and in Tucson, AZ. SJI
carries out research and education in planetary and Earth sciences and
astronomy, with funding provided by government grants and private donations,
which are always needed. Partial funding for the SSU has been provided by
NASA's Office of Space Science.
San Juan Capistrano Research Institute Ph: 714-240-2010, Fax: 714-240-0482
31882 Camino Capistrano, Suite 107 Email: educate@sji.org
San Juan Capistrano, CA 92675 Web site: http://www.sji.org
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=SANA=
Дата: 08 апреля 1998 (1998-04-08)
От: Alexander Bondugin
Тема: STARDUST Update - April 3, 1998
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STARDUST Status Report
April 3, 1998
Ken Atkins
STARDUST Project Manager
Assembly, Test, and Launch Operations (ATLO) activities: ATLO effort
continued wrapping the harness, building/installing the main particle
"Whipple" shield, installing the CIDA (Cometary and Interstellar Dust Analyzer)
keep-alive power (defined last week) converter and preparing for the solar
array switching unit (SASU) interface test. Preparations continued for
installing the flight solar arrays and for the arrival of many key assemblies
for system integration later this month.
The thermal vacuum test on the Sample Return Capsule (SRC) was completed on
both hot and cold cycles. This is to ensure assemblies and wiring have a
lot of margin for any expected thermal environments on the mission.
Additional testing is planned on the deployment mechanisms.
Testing of the Payload & Attitude Control Interface (PACI) board with the
Cometary & Interstellar Dust Analyzer (CIDA) electronics simulator and the
star camera and IMU simulations continued without problems.
Opportunity and Outreach: Increased distribution of informational bookmarks
continued. The Challenger Centers received a supply for their students who
will be participating in their "Rendezvous with a Comet" educational
experience/event.
For more information on the STARDUST mission - the first ever comet sample
return mission - please visit the STARDUST home page:
http://stardust.jpl.nasa.gov
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=SANA=
Дата: 08 апреля 1998 (1998-04-08)
От: Alexander Bondugin
Тема: Neurolab Shuttle Mission To Launch April 16
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Debbie Rahn / Jennifer McCarter
Headquarters, Washington, DC April 3, 1998
(Phone: 202/358-1639)
George Diller
Kennedy Space Center, FL
(Phone: 407/867-2468)
Ed Campion
Johnson Space Center, Houston, TX
(Phone: 281/483-5111)
NOTE TO EDITORS: N98-25
NEUROLAB SHUTTLE MISSION TO LAUNCH APRIL 16
Space Shuttle program managers today affirmed April 16 as the
launch date for NASA's second Shuttle mission of 1998 -- a two
week life sciences research flight that will focus on the most
complex and least understood part of the human body, the nervous
system.
The Flight Readiness Review held at NASA's Kennedy Space
Center, FL, yesterday is the final major review by all Shuttle
project offices to evaluate the readiness of the flight crew and
vehicle, along with launch and mission control flight teams, to
support the launch of Space Shuttle Columbia on the STS-90
Neurolab mission.
Columbia is scheduled for launch on April 16, 1998 from
NASA's Kennedy Space Center Launch Complex 39-B. The 2 1/2 hour
available launch window opens at 2:19 p.m. EDT. The STS-90
mission is scheduled to last 15 days, 21 hours, 50 minutes.
However, mission managers are reserving an option of extending the
flight one additional day for science operations if Shuttle
electrical power margins permit. A launch on April 16, and a 16-
or 17- day nominal mission would have Columbia landing at Kennedy
on May 2 or 3.
The STS-90 Mission Commander is Richard A. Searfoss. Pilot
for the flight is Scott D. Altman. There are three mission
specialists assigned to this mission -- Richard M. Linnehan, who
is also serving as the Payload Commander; Kathryn P. (Kay) Hire;
and Dafydd (Dave) Rhys Williams from the Canadian Space Agency.
Two payload specialists -- Jay Clark Buckey, Jr., and James A.
(Jim) Pawelczyk -- round out the seven member STS-90 crew.
STS-90 will be the 25th flight of Columbia and the 90th
mission flown since the start of the Space Shuttle program in
April 1981.
For complete biographical information on the STS-90 crew and
other astronauts, see the NASA Internet astronaut biography home
page at URL: http://www.jsc.nasa.gov/Bios/
-end-
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=SANA=
Дата: 08 апреля 1998 (1998-04-08)
От: Alexander Bondugin
Тема: This Week On Galileo - April 6-12, 1998
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THIS WEEK ON GALILEO
April 6-12, 1998
Galileo spends most of the week processing and transmitting to Earth
pictures and other science information gathered during the spacecraft's
recent encounter with the Jupiter system. The data returned to Earth this
week includes information on Io, Europa and Jupiter's magnetic and electric
field environment. On Friday of this week, the spacecraft performs regular
maintenance on its propulsion system and then performs a turn to keep its
radio antenna pointed toward the Earth.
This week's data processing schedule starts with an observation performed by
the Near Infrared Mapping Spectrometer (NIMS). The observation contains
science information describing the south pole of Jupiter's volcanic moon Io.
The data is the highest resolution of Io that will be possible through
Spring of 1999 and the best view of Io's south pole possible until the
spacecraft's return to Io in late 1999.
The Photopolarimeter Radiometer team returns one of three observations
performed by their instrument designed to refine maps of temperature
variation across Europa's surface. These maps will be useful in
understanding the different ages of Europa's surface, how the surface might
have been formed and the different materials found on the surface. NIMS and
the spacecraft's camera, or Solid State Imaging (SSI) subsystem, will return
information on a region of dark lines and the Mannann'an crater,
respectively. Together with other observations, the Mannann'an crater
pictures are expected to result in stereo pictures of the region.
Finally, this week's playback and transmission of data recorded on the
spacecraft includes information from the fields and particles instruments
regarding the interaction of Jupiter's magnetic and electric field
environment with Europa. This type of information is gathered during almost
every orbit, with each orbit providing new scientific understanding of these
phenomena.
Preliminary results from last week's attitude control system performance
test have provided indications that the behavior of the system's gyroscopes
did not degrade further during the latest passage through Jupiter's intense
radiation environment last month. In addition, further investigation into
the possible cause of the anomalous behavior has identified a single
computer chip. Of many computer chips involved in the operation of the
spacecraft's gyroscopes, this chip is slightly more exposed to the radiation
environment. The malfunction of this chip seems to be consistent with the
anomalous behavior observed with the attitude control system.
For more information on the Galileo spacecraft and its mission to Jupiter,
please visit the Galileo home page:
http://www.jpl.nasa.gov/galileo/
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=SANA=
Дата: 08 апреля 1998 (1998-04-08)
От: Alexander Bondugin
Тема: First MGS Image Of Cydonia Region Available
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FIRST MGS IMAGE OF CYDONIA REGION
April 6, 1998
The first Mars Global Surveyor image of the Cydonia region
including the "Face on Mars" is now available. The raw
image is available at these locations:
http://mars.jpl.nasa.gov/mgs/target/CYD1/index.html
http://www.jpl.nasa.gov/marsnews/mgs/cydonia/
A processed version of the raw image will be released later
today. If you have difficulty reaching any of these sites
due to the high demand, try one of the mirror sites listed below.
Ron Baalke
CYDONIA PHOTO CAPTION
Orbit: 220
Range: 444.21 km
Resolution: 4.32 m/pixel
Image dimensions: 1024 X 19200 pixels, 4.42 km X 82.94 km
Line time: 0.69 msecEmission angle: 44.66 degrees
Incidence angle: 64.96 degrees
Phase angle: 61.97 degrees
Scan rate: ~0.1 degree/sec
Start time: periapsis + 375 sec
Sequence submitted to JPL: Sat 04/04/98 15:15 PST
Image acquired by MOC: Sun 04/05/98 00:39:37 PST
Data retrieved from JPL: Mon 04/06/98 09:05 PDT
Quick Reference to Mars Global Surveyor Mirror Sites
Sites with Fast Update Capability
Name MGS Mirror Site Address Bandwidth
Update Delay
Digital - USA http://entertainment.digital.com/mars/JPL/mgs300 Mbps 10
Minutes
Sun - USA http://www.sun.com/mars/mgs 225 Mbps 20
Minutes
Silicon Graphics - http://mars.sgi.com/mgs 200 Mbps 3
Minutes
USA
SDSC - USA http://mars.sdsc.edu/mgs 155 Mbps 2
Minutes
AOL - USA http://mars.primehost.com/mgs 100 Mbps 15
Minutes
NASA AMES - USA http://mpfwww.arc.nasa.gov/mgs 100 Mbps 2
Minutes
Keyway - USA http://pathfinder.keyway.net/pathfinder/mgs 90 Mbps 2
Minutes
NCSA - USA http://www.ncsa.uiuc.edu/mars/mgs 55 Mbps 2
Minutes
NASA KSC - USA http://www.ksc.nasa.gov/mars/mgs 55 Mbps 3
Minutes
CSIRO - AUSTRALIA http://sparkli.tip.csiro.au/mars/mgs 34 Mbps 10
Minutes
WEB2MIL - URUGUAY http://web2mil.intercanal.com/mars/mgs 10 Mbps 2
Minutes
PGD - USA http://mars.pgd.hawaii.edu/mgs 10 Mbps 2
Minutes
Riken - JAPAN http://riksun1.riken.go.jp/JPL/mgs 6 Mbps 2
Minutes
NASDA - JAPAN http://mars.tksc.nasda.go.jp/JPL/mgs 1.5 Mbps 2
Minutes
IKI - RUSSIA http://www.iki.rssi.ru/jplmirror/mars/mgs 0.512 Mbps 2
Minutes
THOS - SOUTH AFRICA http://www.southafrica.co.za/mars/mgs 0.128 Mbps 3
Minutes
Sites with Same Day Update Capability
Name MGS Mirror Site Address Bandwidth
Max Update
Delay
Excite - USA http://mars.excite.com/mars/mgs 155 Mbps 12
Hours
Catlin - USA http://mars.catlin.edu/mgs 20 Mbps 12
Hours
Hewlette Packard - http://mars.hp.com/mgs 10 Mbps 12
Hours
USA
Sunsite - DENMARK http://sunsite.auc.dk/mars/mgs 3 Mbps 1
Hour
Ihighway - USA http://mars.ihighway.net/mgs 3 Mbps 12
Hours
CNES - FRANCE http://www-mars.cnes.fr/mgs 3 Mbps 30
Minutes
Sussex - ENGLAND http://tc.cpes.susx.ac.uk/mars/mgs 2 Mbps 12
Hours
Apranet - http://mars.arpanet.ch/mgs 2 Mbps 12
Hours
SWITZERLAND
Egnatia - GREECE http://www.egnatia.ee.auth.gr/mirrors/mars/mgs 2 Mbps 12
Hours
Provider - POLAND http://mars.provider.com.pl/mgs 2 Mbps 12
Hours
FHO - GERMANY http://spot.fho-emden.de/nasa/mgs 2 Mbps 12
Hours
Webdesign - HUNGARY http://mars.webdesign.hu/mgs 1.5 Mbps 12
Hours
SCI-CTR - SINGAPORE http://www.sci-ctr.edu.sg/mars/mgs 0.128
Mbps12 Hours
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=SANA=
Дата: 08 апреля 1998 (1998-04-08)
От: Alexander Bondugin
Тема: New water and remote galaxies complete ISO's observations [1/2]
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European Space Agency
Press Information Note No. 09-98
Paris, France 7 April 1998
New water and remote galaxies complete ISO's observations
Water vapour detected on Saturn's largest moon, Titan, and infrared
galaxies identified at immense distances are among the latest results
from the European Space Agency's Infrared Space Observatory, ISO. At a
press briefing in London today (7 April) ESA's director of science,
Roger Bonnet, said "ISO is one of the most successful space
observatories, and in the infrared it has had no rival." Its discoveries
will change our views on the Universe.
ISO's operational teams at ESA's ground station at Villafranca near
Madrid have been hurrying to provide the world's astronomers with as
many observations as possible. They have long anticipated the exhaustion
of ISO's vital supply of liquid helium, which cooled the infrared
telescope and its instruments to their operating temperatures, close to
absolute zero. Two weeks after ISO was put into orbit on 17 November
1995 by an Ariane 44P launcher, the external parts of the cooling system
had settled to the operating temperature. The specification required
that ISO should then operate for at least 18 months -- implying that
operations might have to end in May 1997.
Thanks to superb engineering by European industry, which built the
spacecraft and its super-cool telescope, ISO has given astronomers
almost a year longer than that. During the extra time the count of ISO's
observations of cosmic objects has risen from 16,000 to about 26,000.
Among the benefits of ISO's longevity has been the chance to examine an
important region of the sky, in and around the constellation of Orion.
This was not accessible in the nominal mission but has now been observed
in two periods.
Four international teams, supported by national funding agencies,
supplied the instruments to analyse the infrared rays received by ISO's
telescope. The principal investigators leading the teams are Dietrich
Lemke (Heidelberg, Germany) for the versatile photometer ISOPHOT,
Catherine Cesarsky (Saclay, France) for the camera ISOCAM, Thijs de
Graauw (Groningen, the Netherlands) for the Short Wavelength
Spectrometer SWS, and Peter Clegg (London, UK) for the Long Wavelength
Spectrometer LWS.
Water vapour on Titan
A big difference between ISO and the only previous infrared astronomy
satellite (IRAS 1983) has been its ability to examine individual objects
across a wide range of accurately defined infrared wavelengths. Many
spectra showing patterns of intensities at the different wavelengths
have enabled astronomers to deduce the presence of diverse materials in
interstellar space, in the surroundings of stars, and in other
galaxies.
As previously reported, ISO has identified stony materials, tarry
compounds of carbon, and vapours and ices like water and carbon
monoxide. Together they give the first clear picture of how Mother
Nature prepares, from elements manufactured in stars, the ingredients
needed for planets and for life itself.
Particularly striking for the human imagination are ISO's repeated
discoveries of water in the deserts of space. They encourage
expectations of life elsewhere in the Universe. Water has turned up
around dying stars, newborn stars, in the general interstellar medium,
in the atmospheres of the outer planets and in other galaxies too. A
link to the Earth's oceans and the water we live by comes in the water-ice
long known to be a major ingredient of comets, which are relics from the
era of planet-building.
A further link to the investigation of the origin of life is the
apparent detection of water vapour in the mysterious atmosphere of
Saturn's largest moon, Titan. A preliminary announcement comes from an
international team headed by Athena Coustenis of Paris Observatory and
Alberto Salama of the ISO Science Operations Center at Villafranca.
The team used ISO's Short Wavelength Spectrometer during several hours
of observations last December, when Titan was at its farthest from
Saturn as seen by ISO. Emissions at wavelengths of 39 and 44 microns
showed up, as an expected signature of water vapour. The news will
excite the scientists involved in ESA's probe Huygens, launched last
year aboard NASA's Cassini spacecraft. It will parachute into Titan's
atmosphere to see what the chemistry of the Earth may have been like
before life began.
"Water vapour makes Titan much richer," comments Athena Coustenis. "We
knew there was carbon monoxide and carbon dioxide in Titan's atmosphere,
so we expected water vapour too. Now that we believe we've found it, we
can expect to better understand the organic chemistry taking place on
Titan and also the sources of oxygen in the Saturnian System. After ISO,
the Huygens probe will reveal the actual degree of complexity in a
mixture of elaborate organic molecules closely resembling the chemical
soup on the young Earth."
Ballet corps of young stars
Infrared images of the spectacular Orion star-forming regions, at a
distance of approximately 1500 light years, are bonuses from ISO's
extended life. In the Horsehead Nebula, visible light shows a large dark
dust cloud from which a black wisp shaped like a horse's head protrudes
into a luminous cloud of gas. When seen by ISO's camera ISOCAM, dense
parts of the dusty region appear as shiny filaments and the horse's head
almost disappears. Young stars are detected in the horse's forehead and
in the nearby nebula NGC 2023.
Other well-known nebulae in the Orion region include NGC 2068 and NGC
2071. Emission by carbon compounds (polycyclic aromatic hydrocarbons or
PAH) makes the infrared nebulae spectacular, as seen by ISOCAM. And
thanks to ISOCAM's sensitivity and the ability of infrared rays to
penetrate a dust cloud better than visible light, ballet corps of young
stars appear on the stage, seen as spots in the centre of these two
nebulae. This is not surprising, because the dense, dusty regions called
molecular clouds are often the breeding grounds of new stars, but ISOCAM
detects fainter and more obscured objects.
"We have used ISOCAM to make a census of families of young stars,"
comment Lennart Nordh and Goran Olofsson of Stockholm University, who
lead a team of astronomers from Sweden, France, Italy, the UK and ESA.
"By comparing the intensities of the point-like objects at different
infrared wavelengths we can efficiently identify the ensemble of young
stars still embedded in its parental molecular clouds."
From their study of ISO's early observations of four star-forming
clouds, the astronomers report the detection of small stars. "Almost 300
young stars have been identified to date, many of which were previously
not recognized," Nordh and Olofsson say. "Most of the latter objects
have luminosities 10-100 times lower than revealed by earlier
observations. Our preliminary analysis indicates that at least ten per
cent of the embedded young stars will become small brown dwarfs, or
ownerless super-planets, less than one-tenth of the mass of the Sun."
Colliding galaxies
Some galaxies are unusually bright in the infrared because of cosmic
traffic accidents that bring them into collision with other galaxies.
The result is a frenzy of star formation called a starburst. The
explosion of short-lived stars then creates a pall of warm dust which
ISO observes in the infrared. The relative intensities of different
wavelengths enable astronomers to distinguish starburst events from
other sources of strong infrared rays, such as the environment of a
black hole in the nucleus of a galaxy. Collisions and starbursts play an
important part in the evolution of galaxies.
A famous pair of colliding galaxies called the Antennae was one of the
first objects to be examined by ISO. Continuing study of the Antennae
over the past two years has revealed a clear picture of a starburst
occurring exactly where the dense disks of the galaxies intersect. The
nuclei of the two galaxies are plainly distinguished too.
Centaurus A is a galaxy that first attracted the attention of
astronomers by its strong of radio emissions. In its visible appearance,
a large, round (elliptical) galaxy has a dark band across its face. This
too turns out to be the result of a galactic collision. The dark band is
a flat, disk-shaped galaxy seen almost edge-on. Centaurus A is the
nearest case of a phenomenon seen elsewhere by ISO, in which a flat
galaxy has merged with an elliptical galaxy while preserving its flat
configuration.
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=SANA=
Дата: 08 апреля 1998 (1998-04-08)
От: Alexander Bondugin
Тема: Early Tests Show Air Turbulence Sensor Could Make Air Travel Safer
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Dwayne Brown
Headquarters, Washington, DC April 6, 1998
(Phone: 202/358-1726)
Kirsten Williams
Dryden Flight Research Center, Edwards, CA
(Phone: 805/258-2662)
Kathy Barnstorff
Langley Research Center, Hampton, VA
(Phone: 757/864-9886)
Anatta
National Center for Atmospheric Research, Boulder, CO
(Phone: 303/497-8604)
RELEASE: 98-57
EARLY TESTS SHOW AIR TURBULENCE SENSOR COULD MAKE AIR TRAVEL SAFER
NASA is testing a new sensor that could make air travel safer
by detecting previously invisible forms of clear air turbulence
and giving pilots time to take safety precautions. Early tests of
the new clear air turbulence sensor are promising, officials say.
Clear air turbulence is an invisible safety hazard for
aircraft. Though seldom damaging to modern aircraft, which are
designed to withstand its stresses, it is the leading cause of in-
flight injuries among the flying public.
"During the tests, the system observed turbulent regions of
air ahead of the aircraft as it moved forward. The aircraft
experienced disturbances as it penetrated the turbulence. In that
scenario, if an alarm were sounded when turbulence was first
detected, passengers could have quickly returned to their seats
and fastened their seatbelts before the encounter," said project
manager Rod Bogue of NASA's Dryden Flight Research Center,
Edwards, CA.
Flights of the detector originated from Jefferson County
Airport, near Broomfield, CO. The experiment was flown on three
separate flights for a total of more than seven hours at altitudes
as high as 25,000 feet. Additional flights are slated to add to
the turbulence database and to fine-tune the sensor for better
measurements.
Currently there are no effective warning systems for clear
air turbulence, which occurs at high altitudes near jet streams
and in the vicinity of mountain ranges, and as far as 50 miles or
more from developing storm systems. It's been referred to as
"rough air" or "air pockets," that can be felt, but not seen.
The sensor device, called Airborne Coherent LiDAR for
Advanced In-flight Measurement, was designed and built by Coherent
Technologies Inc., Lafayette, CO, for NASA. It relies on a form
of laser technology called Light Detection and Ranging (LiDAR), to
detect changing velocities of tiny particles in turbulent air. As
long as the wind velocity remains uniform, no turbulence exists.
But if the laser beam detects changes in the velocity, it's a
clear indication of turbulence ahead. The laser technology is
similar to the more familiar radar and can be envisioned as a kind
of infrared radar. Although conventional radar uses radio waves,
this laser technology relies on infrared light waves.
"The infrared radar concept uses a light pulse transmitted
from the laser, and some of the light is reflected off the
particles back to a sensor at the source," Bogue said. "The
reflected light has a slight shift in frequency, called a Doppler
shift, due to the aircraft's motion relative to the particles. By
analyzing the frequency of the Doppler shift, the changes in wind
velocity along the laser beam's path can be determined," he said.
During its first flight, the flight crew located turbulent
conditions and used the infrared radar to measure the changes in
wind speed -- a measure of turbulence -- before flying through the
disturbed air. Once the aircraft reached the turbulence, the crew
compared the pre-encounter measurements with the effects of the
turbulence they experienced. In this way, the team is exploring
the relationship between the laser radar-measured turbulence
characteristics and the actual turbulence experienced by the
aircraft. These tests are designed to provide an efficient
checkout of the flight hardware and to help characterize
turbulence measurements.
"Not much is known about accurately detecting and forecasting
turbulence," said Larry Cornman, scientist for the National Center
for Atmospheric Research (NCAR), Boulder, CO. "Through this new
device and turbulence research conducted at NCAR, we expect a
clearer picture to emerge to make flying safer."
Dryden is using an aircraft owned by the National Science
Foundation and operated by NCAR. NCAR is managed by the
University Corporation for Atmospheric Research under sponsorship
by the National Science Foundation. Other partners for the
project include NASA's Langley Research Center, Hampton, VA;
NASA's Marshall Space Flight Center, Huntsville, AL; Coherent
Technologies, Inc.; Global Hydrology and Climatology Center;
Huntsville, AL; Boeing Commercial Airplane Group, Seattle, WA, and
the Air Force Research Laboratory Sensor Directorate Multifunction
Electro-Optics Branch, Dayton, OH.
Langley is the Agency's lead center for the NASA Aviation
Safety program. Other participating NASA centers include Dryden,
Ames Research Center, Moffett Field, CA, and Lewis Research
Center, Cleveland, OH.
-end-
Hа сегодня все, пока!
=SANA=
Дата: 08 апреля 1998 (1998-04-08)
От: Alexander Bondugin
Тема: NASA Satellite Will Take Students To The Rainforest
Привет всем!
Вот, свалилось из Internet...
Beth Schmid
Headquarters, Washington, DC April 6, 1998
(Phone: 202/358-1760)
Sally V. Harrington
Lewis Research Center, Cleveland, OH
(Phone: 216/433-2037)
RELEASE: 98-55
NASA SATELLITE WILL TAKE STUDENTS TO THE RAINFOREST
Beginning this week, NASA's Advanced Communications
Technology Satellite (ACTS) will connect students in selected
schools in Iowa, Florida, Texas, New York, Pennsylvania and West
Virginia with scientists at a field research site in the Amazon
rainforest in Brazil.
The Space Communication Office at NASA's Lewis Research
Center, Cleveland, OH, will use ACTS to supply the primary
communication links for "Live from the Rainforest," the latest
segment of an ongoing series of electronic field trips to
scientific frontiers. The links will include both the live video
broadcast from the rainforest and a return link from the
participating classrooms as well as supplementary audio, fax and
Internet connections.
A series of three "Live from the Rainforest" shows will be
aired on the Public Broadcasting System on April 7, 14 and 21,
1998, 1-2 p.m. EDT. The series also will be shown on NASA TV,
available on GE-2, transponder 9C at 85 degrees West longitude,
with vertical polarization. Frequency is on 3880.0 megahertz,
with audio on 6.8 megahertz.
Students will learn about the equipment used to explore the
rainforest and the people, plants, animals and insects of the
largest expanse of virgin rainforest on the planet.
Engineers from Lewis set up an Earth station at the remote
site, where transmissions from the rainforest will be made over
ACTS to an Earth station at Lewis. The video/audio signal from
Lewis will be downloaded using a terrestrial line to the
Mississippi State University (MSU) Television Center, which is
connected to various schools for interaction between the students
and scientists. NASA equipment at MSU will assure the signal from
the participating schools will be downloaded in the proper format
to be compatible with the video/audio in the rainforest.
Lewis has been demonstrating ACTS' capabilities to provide a
wide-bandwidth communication link via satellite to remote
locations, where other means of providing this type of
communication are not available, since shortly after it was
launched aboard the Space Shuttle Discovery in September 1993.
ACTS made it possible for Army reservists stationed in Haiti in
December 1994 to talk face-to-face with their loved ones back home
through videoconferencing. It also has been used to assist in
restoring telecommunication service interrupted by natural and
manmade disasters. In the field of telemedicine, ACTS technology
is being used to evaluate improved techniques for providing women
in remote areas with real-time diagnoses of mammograms through
clear and quick satellite image transmission.
"Live from the Rainforest" is produced by Passport to
Knowledge and is supported by the National Science Foundation and
NASA.
-end-
Hа сегодня все, пока!
=SANA=
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