Дата: 12 ноября 1998 (1998-11-12)
От: Alexander Bondugin
Тема: Европейское космическое агентство готовится к полету на Марс
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Европейское космическое агентство готовится к полету на Марс
[SpaceViews] Европейское космическое агентство (ESA) утвердило
планы разработки проекта Mars Express, который включает и
орбитальный и спускаемый на поверхность Марса аппараты. Экспедиция
на Марс запланирована на 2003 г.
Все 14 стран участниц Комитета научных программ ESA одобрили
концепцию миссии, стоимость которой составит 150 млн евро (175 млн
дол.). По заявлению директора ESA по науке Роджера Бонне (Roger
Bonnet), это будет одна из самых дешевых и оригинальных экспедиций на
Марс.
Старт Mars Express запланирован на июнь 2003 г. Для запуска будет
использована российская ракета "Союз". К Марсу корабль прилетит к
Рождеству 2003 г. Hа космическом корабле будет установлено 7 блоков
научной аппаратуры, некоторые из них будут дублировать те, что были
потеряны при аварии российского корабля "Марс-96" в ноябре 1996 г. В
состав аппаратуры войдут фотокамера высокого разрешения, несколько
спектрографов и радар, способный обнаруживать объекты в толще земли.
Этот радар будет использован для исследования воды, скрытого под
марсианской поверхностью, которая находится там в виде рек, озер,
ледников и вечной мерзлоты.
Mars Express понесет и спускаемый аппарат Beagle 2 весом 60 кг, на
котором будут установлены фотокамера и инструменты для исследования
марсианского грунта и горных пород с целью определения прошлого этой
планеты. Установка остального оборудования будет зависеть от
финансовых возможностей разработчиков.
Источник: InfoArt News Agency
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=SANA=
Дата: 12 ноября 1998 (1998-11-12)
От: Alexander Bondugin
Тема: NASA завершает испытания ракетного двигателя на атмосферном воздухе
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NASA завершает испытания ракетного двигателя на атмосферном
воздухе
[NASA] Hациональное управление по аэронавтике и исследованию
космического пространства США(NASA) успешно завершило двухлетние
наземные испытания принципиально нового ракетного двигателя,
который может существенно изменить будущее космонавтики - этот
двигатель "дышит" кислородом воздуха. По заявлению разработчиков, они
готовы продемонстрировать работу нового двигателя в полете.
С таким двигателем весь космический корабль может быть
использован неоднократно и после приземления он будет готов к полету
уже через несколько дней, что существенно удешевит космические
путешествия и откроет ворота в космос для многих стран мира. Часть
полетного времени двигатель будет брать кислород непосредственно из
атмосферного воздуха, что позволит сократить запасы газа на борту
корабля. Соответственно и весить ракета с таким двигателем будет
меньше. Для начального разгона двигателя будут использоваться
специальные ракеты, мощность которых составит около 15% от мощности
современных ракет-носителей. После того как космический корабль
достигнет удвоенной скорости звука разгоняющие ракеты отделяются, и
двигатель переходит на атмосферный кислород. После разгона до
10-кратной скорости звука включается обычная система вывода
космического корабля на орбиту.
По мнению NASA, при использовании таких двигателей запуск
космического корабля удешевится настолько, что полет в космос станет
доступен и для туристов. Цель NASA - снизить затраты на запуск одного
фунта веса космического корабля с 10 тыс. дол. (около 22 тыс. дол. на
килограмм) до нескольких сотен долларов.
В создании воздушного ракетного двигателя принимали участие
компании Aerojet, Rocketdyne, Astrox, Университеты Пеннсильвании и
Алабамы.
Источник: InfoArt News Agency
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=SANA=
Дата: 12 ноября 1998 (1998-11-12)
От: Alexander Bondugin
Тема: Выход в открытый космос на станции "Мир" прошел успешно
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Выход в открытый космос на станции "Мир" прошел успешно
10 ноября в 22 часа 25 минут космонавты 26-ой экспедиции на
станции "Мир" Геннадий Падалка и Сергей Авдеев совершили выход в
открытый космос для установки на внешней поверхности орбитального
комплекса научной аппаратуры и оборудования. Космонавты провели в
открытом космосе 6 часов - практически полный рабочий день. Объем
работ был довольно большим, так что пришлось шевелиться. В общей
сложности космонавты установили на станции 17 блоков с
оборудованием, самым крупным из которых была солнечная батарея
нового типа. По словам разработчиков эта двухсекционная батарея
является практически вечной, во всяком случае они гарантируют
несколько десятков лет ее безотказной работы. Основной целью ее
установки является изучение поведения новых материалов в открытом
космосе. Была испытана и новая система защиты скафандров от внешнего
космического излучения и выхлопных газов орбитальной станции.
Установлен российско-французский датчик-ловушка космических
частиц. Он пройдет проверку боем уже 17 ноября - именно тогда станция
попадет в метеорный поток Леонид, а такое событие в окрестности Земли
происходит раз в 33 года. Станция войдет в поток Леонид 17 ноября в 22
часа по московскому времени. В течение часа частицы будут
бомбардировать станцию. По мнению ученых никакого ущерба станции
нанесено не будет (частицы очень малы), но тем не менее экипаж во
время прохождения метеорного потока будет на всякий случай находиться
в спускаемом аппарате, чтобы в случае необходимости быстро вернуться
на Землю.
Часть оборудования была установлена в рамках программы
разработки Международной космической станции. Кроме того
космонавты в буквальном смысле слова вручную запустили на орбиту
макет первого искусственного спутника Земли размером втрое меньше
оригинала. Hачинка этого спутника была собрана российскими и
францускими школьниками, он в течение нескольких минут передавал в
космическое пространство несколько фраз на русском, французском и
английском языках. К сожалению, космонавтам не удалось высвободить
место на поверхности станции для российского прибора,
предназначенного для измерения различных излучений.
Источник: InfoArt News Agency
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=SANA=
Дата: 12 ноября 1998 (1998-11-12)
От: Alexander Bondugin
Тема: Leonid Meteor Shower Prospects for UK and Europe (Forwarded)
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Royal Astronomical Society
For immediate release: 10 November 1998
Ref. PN 98/23
Issued by:
Dr Jacqueline Mitton
RAS Public Relations Officer
Office & home phone: Cambridge ((0)1223) 564914
Mobile phone: 0370 386133
FAX: Cambridge ((0)1223) 572892
E-mail: jmitton@dial.pipex.com
and
Peter Bond
Space Science Advisor
Phone: (0)1483-268672
Fax: (0)1483-274047
E-mail: 100604.1111@compuserve.com
Leonid Meteor Shower Prospects for UK and Europe
Professional and amateur skywatchers worldwide are awaiting the night of
17th/18th November with considerable anticipation because of the possibility
that a spectacular meteor shower will take place. But what can we really
expect to see in the UK and rest of Europe?
According to the best data available, Europe is likely to experience a good
meteor shower, but not a truly exceptional one -- perhaps up to 100 meteors
per hour if we are lucky. The best time to look will be between 1 a.m. and
dawn in the early hours of 18th November. A storm of many thousands of
meteors per hour could occur, but it is much more likely to be seen in the
Far East -- China, Thailand, Japan -- than in Europe.
Forecasting Metoer Showers
Predictions of a meteor storm in 1998 are based on the fact that exceptional
displays of the Leonid meteors -- so-called because they appear to radiate
from a point in the sky within the constellation Leo -- tend to recur every
33 years or so. There is not always a great storm, however, such as the one
in 1966 when observers in parts of the USA for a short time saw meteors at
a rate of 40 per second.
But forecasting meteor showers is not a precise business, unlike predicting
eclipses, for example, for which the exact times and circumstances can be
calculated in advance. The time when a meteor shower will peak, and the
maximum rate at which meteors will appear to rain down, can never be
anticipated with great certainty. They are something of a celestial lottery.
For that reason, it is well worth looking out for meteors in the early hours
of the 18th, if skies are clear, even from the UK. There is a slim chance of
something exceptional, but a modest display at least is on the cards, and
meteors are easy to observe. They are best seen with the naked eye and,
during a shower, they can streak across almost any part of the sky, as long
as the radiant point is above the horizon.
If a Leonid storm takes place, it is unlikely to last more than an hour or
so, but the gentler background shower carries on for a day or two. According
to the experts the expected peak time of any storm is most likely to be
about 7.45 p.m. (GMT). If this is correct, the storm would be finished
several hours before the constellation Leo rises above the horizon in the
UK.
What Are Meteors?
Meteors are caused by small fragments of material, mostly no larger than a
grain of sand, which burn up as they enter Earth's atmosphere at high speed --
around 71 kilometres (45 miles) per second in the case of the Leonids.
Leonid meteors are dust particles that have come off Comet Tempel-Tuttle.
Most of this dust is still following the comet fairly closely in space. The
comet takes 33 years to complete an orbit around the Sun, and planet Earth
ploughs through its main dust cloud when the comet returns to our vicinity
every 33 years. In the years when this happens, a strong shower or storm
takes place. In the years in between, a very small number of Leonid meteors
are seen in mid-November.
Some meteor showers produce about the same rate of meteors around the same
date every year. Regular annual showers happen when the dust from a comet
has spread around the whole of the comet's orbit, something that takes place
gradually over a long period of time. An example is the Orionids, a shower
in late October each year caused by dust from Halley's Comet.
Looking ahead to 1999, Comet Tempel-Tuttle will still be relatively nearby
and some astronomers are predicting that the Leonid meteor display could be
better next year than this. If that were to happen, then Europe is expected
to be the ideal location.
Do The Leonids Present Any Hazards?
Most of the Leonids weigh about 1 millionth of a gram -- not much more than
a particle of cigarette smoke. Normally, objects this size would pose no
threat to spacecraft. However, when they are travelling many times faster
than a bullet from a high velocity rifle, the threat increases significantly.
Since the velocity of the meteor impacts is affected by a spacecraft's
motion as it orbits the Earth, hits could occur at any speed between 65 and
80 km (40 and 50 miles) per second. These could result in some physical
damage in sensitive areas as well as electrical short circuits, plasma
discharges, and computer malfunctions, which may be sufficiently serious to
disable a satellite. A form of sand-blasting can erode outer surfaces such
as thermal blankets, mirrors and solar cells. Large impacting particles may
even knock a satellite out of its normal position, as happened to the
European Space Agency's Giotto spacecraft during its 1986 flyby of Halley's
Comet.
"These microparticles could penetrate a fairly weak spacecraft skin," said
Professor Tony McDonnell of the Unit for Space Sciences and Astrophysics at
the University of Kent in Canterbury. However, the most likely form of
damage is to vulnerable power systems. "Perhaps a handful of satellites
could have unusual electrical anomalies," said McDonnell.
Past evidence suggests that the risks are fairly low. During the past four
decades, only one spacecraft, the European Space Agency's Olympus satellite,
is known to have been disabled by a (Perseid) meteor. Furthermore, no
spacecraft were damaged by the 1966 Leonid storm. On the other hand, there
are now more than 500 spacecraft orbiting the Earth, over 10 times as many
as in the mid-1960s.
"The biggest uncertainty is the hourly rate (of arrival)," said Professor
McDonnell. "If this reaches 150,000 per hour, there will be all sorts of
damage, but there may only be 1,800 per hour."
While the probability of any satellite being hit is thought to be less than
0.1%, many spacecraft operators are taking no chances. The Space Shuttle
mission that carried John Glenn was deliberately timed to avoid the Leonid
shower. Cosmonauts on the Mir space station do not have the luxury of
choosing their flight window. While the Mir station presents a large target
for the Leonids, no serious damage is expected. However, the two crewmen may
play safe by moving into the Soyuz lifeboat at the peak of the shower.
Fortunately, the direction from which the particles approach the Earth is
almost perpendicular to the direction of the Sun. This means that the chance
of a direct hit will be substantially reduced since most satellites will
already have their solar panels aligned edge-on to the shower.
Further damage-limitation measures have been recommended by the European
Space Operations Centre operated by the European Space Agency. These include
turning spacecraft so that their most vulnerable systems are not in the
direct line of fire; switching off high voltage systems; and putting a team
of ground controllers on alert in case of emergencies.
In the case of the Hubble Space Telescope, its all-important mirror will be
turned away from the shower during observations of distant galaxies. Most of
the scientific instruments on the European ERS-1 and ERS-2 Earth observation
satellites and the Solar and Heliospheric Observatory (SOHO) will be powered
down and placed in 'sleep' mode during the shower. SOHO and the American
Advanced Composition Explorer (ACE), which are located 1.5 million km
sunward of the Earth, will be particularly at risk since the main stream of
meteors is expected to pass much closer to them than any of their
Earth-orbiting brethren. Indeed, the trail of Leonids will actually travel
between the Earth and these two solar observatories.
More Information about the Leonid Meteors may be found at the following Web
Sites:
Leonid '98 Meteor Outburst Mission Homepage (P. Jenniskens - NASA)
http://www-space.arc.nasa.gov/~leonid/1998.html
Leonid Information for the Beginning and Advanced Meteor Enthusiast
(G. Kronk)
http://medicine.wustl.edu/~kronkg/leonids.html
SKY Online's Meteor Page (Sky & Telescope magazine)
http://www.skypub.com/sights/meteors/meteors.html
Visual Material
Sky & Telescope magazine (based in Boston, USA) has available for
distribution:
* still images from the 1966 Leonid storm,
* artistic renderings
* video of the 1997 Perseid and Geminid meteor showers
* a broadcast-quality, 1-minute animation of why the Leonids occur by
artist Don Davis.
Anyone wanting these for reproduction or broadcast can contact Irene
Szewczuk (irenes@skypub.com, phone 00 1 617-864-7360 x127) or Kelly Beatty
(kbeatty@skypub.com, phone 00 1 617-864-7360 x148). Fax for both is
00 1 617-576-0336.
Andrew Yee
ayee@nova.astro.utoronto.ca
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=SANA=
Дата: 12 ноября 1998 (1998-11-12)
От: Alexander Bondugin
Тема: NEAR Weekly Report for Nov. 6, 1998
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NEAR WEEKLY REPORT
November 6, 1998
MISSION OPERATIONS:
The NEAR spacecraft state/configuration has remained nominal (Flight
Computer #1 and Attitude Interface Unit #1 active).
The Magnetometer and XGRS instruments remained on throughout this
reporting period. The MSI and NIS were successfully powered up in
preparation for the Eros Monochrome Light Curve on November 5 and
NIS/MSI rotation Sequence Dry Run on November 9. Today's track should
indicate how successful the Eros Monochrome Light Curve was. It should
be noted this includes the first images of Eros taken by NEAR.
Due to problems at DSN station 34, data recorded and played back from
98:303-00:55:03 to 98:303-20:31:43 was not recovered at the DSN station.
Attempts to replay the data from the station produced data of a quality
to low to be processed. This playback occurred during an unattended
(MOC) playback. Data for the time period in question is
non-recoverable.
DSN 54 track on Wednesday November 4 was a "no go". The station
reported problems at start of track and remained "red" the entire track.
No data automatically dumped from the spacecraft via time tagged
commands during this ATTENDED track was recovered by the DSN.
Fortunately, an UNATTENDED track with station 25 followed the 54 track.
The NEAR team manned the UNATTENDED track and successfully issued
contingency commands to replay the data a second time. This time the
data was retrieved from the DSN. No net data loss resulted.
Upcoming Spacecraft Activities:
November 9: NIS/MSI Rotation Sequence Dry Run
November 18: Fancy Momentum Dump Test #2
November 19: Monochrome Light Curve of Eros
November 19: NIS Cal Target Observation
November 20: Eros Optical Navigation A (16 frames)
Debra Fletcher
240-228-8274/Washington
443-778-8274/Baltimore
Fax: 240-228-3237
Email: debra.fletcher@jhuapl.edu
Bldg.-Rm.: 2-155
The Johns Hopkins University
Applied Physics Laboratory
11100 Johns Hopkins Road
Laurel, MD 20723-6099
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=SANA=
Дата: 12 ноября 1998 (1998-11-12)
От: Alexander Bondugin
Тема: Goddard spacecraft prepared for encounter with Leonid meteor storm (Fo
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Mark Hess/Jim Sahli
Goddard Space Flight Center Nov. 9, 1998
Greenbelt, MD 20771
(Phone: 301-286-8955)
RELEASE NO: 98-184
GODDARD SPACECRAFT PREPARED FOR ENCOUNTER WITH LEONID METEOR STORM
Flight controllers are laying plans to prepare an orbiting fleet of 22
Goddard spacecraft for the upcoming Leonid meteor storm, predicted to be the
fiercest in more than three decades.
The annual Leonid shower -- this year a storm -- is expected to be unusually
intense because the Earth is crossing Comet Tempel-Tuttle's orbital path at
a time when the comet has recently passed by. This happens once every 33
years when Tempel-Tuttle makes its closest approach to the Sun. The Sun's
radiation boils bits of dust and sand off the comet, littering its path with
debris.
Where possible, controllers will change the orientation of satellites to
reduce the possibility that one of these tiny particles (1 to 100 microns in
size, or about the size of a small sand grain) will strike and disable a
spacecraft. However, Leonid storms pose a greater than usual threat to
spacecraft not only because of the many tiny meteors (thousands per hour)
hitting our atmosphere, but also the tremendous velocities of the particles.
As the Earth moves across the comet's trail, Leonid particles will enter the
planet's atmosphere. Like two freight trains hurtling at one another on the
same track, the distance between the massive debris cloud and the Earth
closes at a mind-boggling 45 miles per second, or over 200 times the speed
of sound. In contrast, Perseid meteors reach speeds of about 37 miles per
second, and typical daily meteors achieve velocities of about 12 miles per
second.
On spacecraft where it is practicable, high voltage systems that supply
instruments will be turned off, or ramped down, to safeguard against the
potential for electrical damage as a result of the satellite's plunge into
the debris cloud. The tiny meteors can hit the spacecraft like a sandblaster
and disintegrate, creating a cloud of electrically charged plasma. Under the
right conditions, this plasma cloud can set off a chain reaction causing a
massive short circuit. The loss of the European Space Agency's Olympus
communications satellite in 1993 was attributed to a strike from the Perseid
shower, and the resulting plasma discharge that zapped the spacecraft's
delicate electronics.
The 22 NASA spacecraft under Goddard's control -- from the 24,500 pound
Hubble Space Telescope to the 25-year old, 800 pound IMP-8 satellite -- will
be continuously monitored during the peak of the storm, and some maneuvered
to provide the greatest protection possible from debris.
"Each individual mission and project team reviewed its procedure for dealing
with this annual phenomena, and has a specific implementation plan for the
Leonid meteor storm," said Philip E. Liebrecht, Associate Director for
Networks and Mission Services. "Each spacecraft has an operating plan that
balances the risk of taking specific defensive measures against the risk of
taking no action. We've had independent review teams assess our plans, and I
think we are doing everything prudent and practicable to ensure the safety
of our spacecraft."
The Leonid meteor shower arrives every November. It takes its name from the
constellation Leo, the area of the sky where the meteors appear to
originate. The shower's small particles are completely vaporized high in the
Earth's atmosphere, and present no danger to the Earth's surface or to
aircraft.
Historically, the most active Leonid showers occur during the first two
years following the comet's closest approach to the Sun. This last occurred
on Feb. 28, 1998. This year's outburst is projected to be less severe than
that observed in the last 33-year cycle, which occurred in 1966. The peak
time for the Leonid meteor storm will be Nov. 17, sometime between 11:43 a.m
and 5:43 p.m. Eastern Standard Time.
For the past several weeks, engineers at Goddard have been reviewing the
status of all the spacecraft under their control and developing ways to
reduce exposure to the meteor storm. In general, the health of these
spacecraft will be monitored before, during and after the storm, and
commands to a number of the spacecraft will be stopped or curtailed during
this period.
The Hubble Space Telescope will be maneuvered so that its mirrors face away
from the storm. Its solar arrays will be rotated so only the edges are
exposed to oncoming particles. Controllers won't turn Hubble off during the
storm, but rather use the 10-hour period that Hubble is maintained in this
attitude to take a long-exposure picture (for more on this, check out
http://www.stsci.edu/ftp/proposer/leonid.html).
Some spacecraft, like the Tropical Rainfall Measuring Mission, are already
in the ideal orientation for the storm, and only an adjustment to position
the solar arrays "edge on" to the storm will be needed. The Rossi X-ray
Timing Explorer's instruments will be turned off to protect the spacecraft's
high voltage devices from a potential massive short circuit similar to what
happened to Olympus.
For the Advanced Composition Explorer, the solar arrays will be rotated, and
high voltage supplies for instruments will be ramped down. Since the center
of the Leonid stream is closer to the L-1 orbit (1 million miles from the
Earth toward the Sun) than to Earth, ACE will see an even more intense storm
than Earth-orbiting satellites.
Risk reduction procedures will be followed for other spacecraft including
the Extreme Ultraviolet Explorer, Compton Gamma Ray Observatory, Upper
Atmosphere Research Satellite, Total Ozone Mapping Spectrometer, Fast
Auroral Snapshot, Solar Anomalous Magnetospheric Particle Explorer,
Transition Region and Coronal Explorer, WIND, POLAR, Solar and Heliospheric
Observatory, Interplanetary Monitoring Platform and Earth Radiation Budget
Satellite.
The Tracking and Data Relay Satellites will be maintained in their full
operational mode, as these spacecraft are vital to provide the
communications link to and from other spacecraft during the peak storm
period.
Flight control teams for all of Goddard's operational spacecraft have been
briefed on the meteor storm and have developed contingency plans to react to
any damage sustained during the storm. In addition, all available command
and control capabilities will be on alert for possible use in an emergency,
and subsystem engineers will be on standby for consultation if there are any
problems resulting from the storm.
More information on the Leonid meteor storm can be found at these web sites:
http://www.aero.org/leonid/index.html
http://www-space.arc.nasa.gov/~leonid/
http://leroy.cc.uregina.ca/~astro/Leonids/Leo_1.html
Andrew Yee
ayee@nova.astro.utoronto.ca
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=SANA=
Дата: 12 ноября 1998 (1998-11-12)
От: Alexander Bondugin
Тема: Research Aircraft Fly Below Leonid Meteor Storm (Forwarded)
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NOTE: The "Once-in-a-Century" claim in the news release needs to be
clarified. - A.Y.
*****
National Science Foundation
Washington, D.C.
Media contact: Cheryl Dybas, NSF (703) 306-1070 cdybas@nsf.gov
Media contact: Anatta, UCAR Communications (303) 497-8604 anatta@ucar.edu
Program contact: Cliff Jacobs, NSF (703) 306-1521 cjacobs@nsf.gov
NSF PR 98-74 November 6, 1998
Research Aircraft Fly Below Once-in-a-Century Leonid Meteor Storm
Two research aircraft carrying new scientific observing instruments and high-
definition TV cameras will seize a once-in-a-lifetime opportunity to observe
the Leonids meteor shower on November 17, 1998. Only once a century does
Earth's orbit cross the dense part of the tail of Comet Temple-Tuttle, which
produces the storm.
An L-188C Electra, owned by the National Science Foundation (NSF) and
operated by the National Center for Atmospheric Research (NCAR) in Boulder,
Colo. will be joined by an Air Force KC-135 in the night skies over Okinawa,
Japan, during the meteor storm.
"The NSF Electra is an ideal platform to participate in the Leonids meteor
experiment," says Cliff Jacobs, program manager in NSF's division of
atmospheric sciences, which funds NCAR. "Its ability to accommodate multiple
state-of-the-art, upward-looking instruments will provide an exceptional
opportunity to study these meteors."
The meteor storm will occur when Earth enters the dense debris behind Temple-
Tuttle on November 17, 1998, and again on November 18, 1999. Although the
comet returns every 33 years, its orbit crosses Earth's only once every
hundred years. This century's crossing offers scientists a close look at the
trails of unusually fresh and large (millimeter- to centimeter-size) meteors
entering the earth's atmosphere at the fastest possible speeds -- 72
kilometers per second (160,000 miles per hour). Best observations will be
from East Asia (China and Japan). Next year, Europe and North Africa will
offer the best viewing. From the ground, the source of the storm appears in
the constellation Leo.
The National Aeronautics and Space Administration is heading the experiment,
which is the first mission in NASA's Astrobiology Program, created to study
the origin and prevalence of life in the universe. The Leonid Multi-
Instrument Aircraft Campaign is also supported by NSF, the U.S. Air Force,
and NHK Japanese television.
The two aircraft are needed to take the observing instruments into clear
skies above the weather-laden lower atmosphere. The Air Force's FISTA (Flying
Infrared Signatures Technology Aircraft) will circle the NSF/NCAR Electra in
a racetrack pattern between 30,000 and 40,000 feet while the Electra flies
back and forth (north-south) about 10,000 feet lower within the loop. At
these altitudes (7 to 10 kilometers, or roughly 4 to 6 miles) both planes
will be safe from the meteors above, which will burn up at 100 to 120
kilometers (60 to 75 miles) above the ground.
A major scientific goal of the mission is to determine how a meteor's mass
compares to its brightness. To date, scientists can only guess how much
material enters the atmosphere during a meteor shower. The Electra will
carry a dual-beam lidar (laser-based radar) built this year to detect iron
vaporized from the meteors in the upper atmosphere. Says NCAR project manager
Bruce Morley, "We know very little about iron in the atmosphere and even
less about the iron contribution from meteors. Observing just one meteor
accurately from the sky would make a big difference to our understanding."
-NSF-
Editors: High-resolution color photos of the Electra are available via the
Internet using anonymous ftp: Log on to ftp.ucar.edu, using the userid:
anonymous password: [your e-mail address] directory: /communications
[include the slash] filenames: elecnight1.tif, elecnight2.tif,
elecnight3.tif, elecnight4.tif, and electra.tif
Andrew Yee
ayee@nova.astro.utoronto.ca
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=SANA=
Дата: 12 ноября 1998 (1998-11-12)
От: Alexander Bondugin
Тема: NASA Technology Helps Smithsonian Preserve The Star-Spangled Banner
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Douglas Isbell
Headquarters, Washington, DC November 10, 1998
(Phone: 202/358-1753)
Bill Steigerwald
Goddard Space Flight Center, Greenbelt, MD
(Phone: 301/286-5017)
Linda St. Thomas
Smithsonian Institution, Washington, DC
(Phone: 202/357-2627)
RELEASE: 98-201
NASA TECHNOLOGY HELPS SMITHSONIAN
PRESERVE THE STAR-SPANGLED BANNER
A NASA infrared camera developed to explore Mars will
assist the Smithsonian Institution in its three-year project
to preserve the Star-Spangled Banner.
The camera, built at NASA's Goddard Space Flight Center,
Greenbelt, MD, is taking images this week of the historic
flag in infrared light to help preservationists identify
deteriorated and soiled areas not obvious to the human eye.
The camera, called the Acousto-Optic Imaging Spectrometer
(AImS), was developed by Dr. David Glenar at Goddard.
Considered a national treasure, the Star-Spangled Banner
flew over Fort McHenry in Baltimore, MD, during the War of
1812 and inspired the words that became the U.S. national
anthem. Despite receiving extra special care at the
Smithsonian's National Museum of American History (NMAH), the
flag is deteriorating from decades of exposure to light, air
pollution and temperature fluctuations.
"It gives me a feeling of great pride that a camera we
developed to explore other planets is now exploring this
historic artifact," said Dr. John Hillman, lead of the camera
group at Goddard and NASA's representative on the Smithsonian
team. "The flag has never been viewed this way before, and
we will see what cannot be seen with the unaided eye. This
exciting project is one of many practical applications for
this imaging technology."
AImS will take 72 separate images that will be pieced
together using a computer to create a mosaic of the massive
flag, which is 30 feet wide and 34 feet long. Each image
takes approximately 25 minutes to make and is composed of 200
infrared wavelengths, or colors.
Infrared light is invisible to the human eye, lying
beyond the red end of the visible portion of the
electromagnetic spectrum. A spectrometer in the camera will
be used to separate the light and reveal its component
wavelengths, similar to the way a prism separates visible
light into a rainbow of colors.
"Wool is the major component in the surface composition
of the flag, and contaminants found on the surface of wool
reflect infrared light differently than wool itself," Hillman
explained. "With AImS, we can identify where these
differences are located on the flag. We are looking for
things that can't be seen easily, or at all, with the human
eye, such as moisture and oils. Moisture is of particular
concern because, in the presence of light, it causes a
chemical reaction that deteriorates wool."
"I selected AImS because of its special ability to make
an image with reflected infrared light," said Suzanne
Thomassen-Krauss, chief conservator of the Star Spangled
Banner Project at the NMAH. "A typical infrared camera
relies on thermal infrared, which is light emitted by an
object due to its heat, but these cameras cannot identify
contaminants on the flag because they are the same
temperature as the flag itself."
After the preservation effort is complete, the Star
Spangled Banner will be returned to a newly renovated Flag
Hall at the NMAH in Washington, DC.
The AImS team is developing a demonstration camera for
the Mars Instrument Development Program funded by NASA
Headquarters. Under this program, a camera using AImS
technology could be a candidate for use on robotic Mars
lander missions in 2005 and beyond. The camera would be used
to determine the mineral composition of Martian rocks.
The camera also can be used to explore the invisible
world here on Earth. A cooperative agreement to use AImS in
skin cancer research is in place with Goddard, Swales and
Associates, Inc., and the Georgetown University Medical
Center Department of Dermatology. "We also have had
preliminary discussions with the University of Arizona,
Tucson, to use our camera to analyze prehistoric sites," said
Hillman.
In addition, Hillman may apply the camera in his
personal efforts as a copyist at the National Gallery of Art,
which involves detailed reproductions of classic art works to
gain insights into the technique, motivations and intentions
of the artist.
"AImS could permit a deeper understanding of a painting by
revealing the underdrawing, which shows what the artist had
in mind before applying the brush," Hillman said. "Another
potential application for this camera is to determine the
pigment used in the paint, which can distinguish an authentic
piece from a forgery."
The AImS team includes Drs. Hillman and Glenar; Cheryl
Vorvick and Chuck Peruso at Goddard; Dr. Nancy Chanover of
the Astronomy Department at New Mexico State University in
Las Cruces; Dr. Bill Blass of the University of Tennessee in
Knoxville; and
Dr. Jeff Goldstein of the Challenger Center for Space Science
Education.
-end-
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=SANA=
Дата: 12 ноября 1998 (1998-11-12)
От: Alexander Bondugin
Тема: ACE spacecraft braces for fierce meteor storm (Forwarded)
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Applied Physics Laboratory
Johns Hopkins University
Laurel, Maryland
Contact:
For ACE Spacecraft Design and Construction:
Ben Walker
JHU Applied Physics Laboratory
Phone: 240-228-6792 E-mail: Ben.Walker@jhuapl.edu
For ACE Mission Operations:
Jim Sahli
Goddard Space Flight Center
Phone: 301-286-8955 E-Mail: james.sahli.1@gsfc.nasa.gov
FOR IMMEDIATE RELEASE: 10 November 1998
ACE SPACECRAFT BRACES FOR FIERCE METEOR STORM
Like Key West store owners anticipating a hurricane, flight controllers at
the NASA Goddard Space Flight Center, Greenbelt, Md., are doing what they
can to prepare the 22 orbiting spacecraft under their command to meet the
November 17 Leonid meteor storm, predicted to be the fiercest in more than
three decades.
Each November 17 the Earth and its swarm of orbiting satellites passes
through the Leonid meteor stream, which originates from the wake of Comet
55P/Tempel-Tuttle. In most years the Leonid shower (so named because the
meteors appear to come from the direction of the constellation Leo) is
unimpressive. But once every 33-1/4 years -- this year - the Earth passes
through Tempel-Tuttle's path just after the comet has made its closest
approach to the sun, when dust, sand, and other materials have been freshly
boiled up from the comet's surface by the sun's radiation and left in its
trail.
NASA technicians are changing the orientation of spacecraft and ramping down
their high voltage supplies to reduce the risk of damage as they plunge
through the massive cloud of Leonid particles at a speed of 45 miles per
second for approximately six hours. They are maneuvering the Hubble Space
Telescope so its mirrors face away from the storm and adjusting other
spacecraft so their solar arrays will meet the storm "edge-on."
At most risk, scientists say, will be the Advanced Composition Explorer
(ACE) spacecraft designed and built by The Johns Hopkins University Applied
Physics Laboratory (APL), Laurel, Md. Launched in August 1997, ACE is in
orbit at a point 1 million miles from Earth toward the sun, a position that
will take it closest to the center of the comet's wake as we pass through.
ACE carries nine instruments designed to study energetic particles from the
sun, interplanetary space, and regions beyond. But none of these instruments
is designed to look at the tiny dirt and dust particles the spacecraft will
soon encounter. In fact, they'll be ducking their heads.
Mary Chiu, ACE Program Manager at APL, says, "We hope for the best, but we
really can't predict what will happen. The probability of getting hit by a
particle that could cause damage is still fairly small, but, depending on
the size of any given particle and where it might hit, the possibility for
problems exists."
To the extent possible, NASA will maneuver ACE so that the backs of solar
arrays will face the meteor storm and three of the most sensitive
instruments -- the Solar Energetic Particle Ionic Charge Analyzer, the Solar
Isotope Spectrometer, and the Cosmic Ray Isotope Spectrometer -- will be
pointed away from it.
"We're standing by to help the NASA team analyze and assess any problems
that might result from the storm," Chiu says. "But at the same time, we're
crossing our fingers in hopes for an uneventful day on November 17."
This dramatic encounter with the Leonid meteor storm will not be visible to
amateur stargazers in America, who, like sensitive instruments on NASA
spacecraft, will be on the back side of the Earth as it roars through the
cloud of particles.
The Applied Physics Laboratory is a not-for-profit laboratory and
independent division of The Johns Hopkins University. APL conducts research
and development primarily for national security and for nondefense projects
of national and global significance. APL is located midway between Baltimore
and Washington, D.C., in Laurel, Md.
Andrew Yee
ayee@nova.astro.utoronto.ca
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=SANA=
Дата: 12 ноября 1998 (1998-11-12)
От: Alexander Bondugin
Тема: Weather Balloon To Be Launched To Observe Leonids
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ADVISORY: 98-234
Marshall Scientists to Launch Weather Balloon; On-board Camera to Broadcast
Images of Leonids Meteors on Web
On Nov. 17, scientists from the NASA Marshall Space Flight Center's
Space Sciences Laboratory in Huntsville, Ala., plan to launch a weather
balloon carrying a digital camera to about 100,000 feet for a clearer view
of the Leonids Meteor Shower. The Leonids meteor storm is expected to be the
most spectacular in years.
Scientists will launch the balloon sometime near midnight from
Marshall's Atmospheric Research Facility, dependent upon weather conditions.
Both still images and low-resolution television captured by the on-board
camera will be available online at the Space Sciences Laboratory Web site
at:
http://science.nasa.gov
Live downlink television also will be carried on cable TV channel 58 over
amateur radio frequency 426.250 Mhz. A special set-up must be followed, and
viewing instructions will be available at the Space Sciences Laboratory Web
site.
For more information, contact Tim Tyson with Marshall's Media
Relations Office at (256) 544-0994 or (256) 544-0034. For an electronic
version of this advisory or more information, visit Marshall's News Center
Web site at:
http://www.msfc.nasa.gov/news
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=SANA=
Дата: 12 ноября 1998 (1998-11-12)
От: Alexander Bondugin
Тема: Leonid Meteor Storm Won't Deter Hubble From Space Observations
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FOR RELEASE: 9:00 a.m. (EST) November 10, 1998
CONTACT: Ray Villard
Space Telescope Science Institute, Baltimore, MD
(Phone: 410-338-4514)
(e-mail: villard@stsci.edu)
PRESS RELEASE NO.: STScI-PR98-40
LEONID METEOR STORM WON'T DETER HUBBLE FROM SPACE OBSERVATIONS
The anticipated celestial bombardment called the Leonid meteor storm
on the afternoon of November 17th (EST) won't deter NASA's Hubble Space
Telescope from its key mission of gazing far across the universe -- as
long as the view is in the opposite direction of the incoming meteor
swarm.
Using the brilliant glow of a distant quasar located near the southern
boundary of the constellation Aquarius, Hubble will probe galaxy
formation and the distribution of matter in space. The Hubble data
will become immediately available to the astronomical community.
The meteor storm is an expected downpour of thousands of meteors
zooming by Earth. They pose a small but potential threat to Hubble and
other satellites, say experts. The meteors appear to come from the
direction of the zodiacal constellation Leo the Lion, and hence the
storm is called the Leonids.
For a 10-hour period at the peak of the storm, estimated to be at
approximately 2:43 p.m. Eastern Standard Time on the 17th, the
telescope will be oriented with its aft bulkhead facing into the
direction of the meteoroid stream. Hubble's solar panels will lay flat,
or parallel to the meteoroid flow.
Though most Leonid meteoroids are smaller than a grain of sand, they
zoom across space at a menacing 155,000 miles per hours. A speck-sized
meteoroid can pack the wallop of a .22 caliber bullet as it pierces
the spacecraft hull.
Still, even at the peak of meteor activity the density of particles in
any given region of space is extremely low. So, project scientists
predict that Hubble has less than a 1-in-10,000 chance of being hit by
a particle large enough to pierce it's aluminum skin.
Smaller meteoroids vaporizing on impact create a plume of plasma that
can short-circuit spacecraft electronics. However, a short circuit on
Hubble is unlikely because its electronics are housed inside aluminum
boxes that also serve as a meteoroid shield.
The Space Telescope won't be idle during the shower. STScI director
Steven Beckwith is making his discretionary observing time available so
astronomers can still observe the heavens while the orbiting
observatory is aimed away from the meteoroid barrage.
Hubble will be aimed at a quasar, the bright core of an active galaxy,
approximately 10 billion light-years away. Hubble won't be studying
the quasar itself but the surrounding galaxies, protogalaxies and
primordial hydrogen clouds between us and the quasar. The quasar is so
brilliant, it is like a searchlight shining through fog.
Strung along billions of light-years, like beads on a string, the gas
clouds will be detectable in the way they subtract certain colors or
frequencies of the quasar's light. The observation will help determine
whether the clouds are cold primeval hydrogen or are sites of ongoing
star formation which have been enriched with heavier elements.
Hubble's Space Telescope Imaging Spectrograph will take a
long-exposure picture to identify galaxies along the sight, and divide
the light into a rainbow of colors (a spectral image) to determine
galaxy distances. This is accomplished by measuring how the light has
been stretched or redshifted by the universe's expansion.
Follow-up spectroscopic observations with large ground-based
telescopes and high-resolution spectrographs will measure the quasar
light directly and identify the distance of the intervening gas
clouds.
The redshifts of the gas clouds from the ground-based data will then
be matched with the redshifts of the galaxies along the line of sight
seen in the HST data. These combined observations will allow
astronomers to see if galaxies are associated with these invisible
clouds.
LEONID STORM HISTORY
The Leonid meteor storm occurs as Earth passes through a region of
concentrated, fresh debris within the stream that follows Comet P/55
Tempel-Tuttle.
The comet made its last closest passage to the sun in late February of
this year. Warmed by the sun, the icy comet nucleus spewed a great
deal of dust into space as its ices melted. These dust particles appear
as meteors when they enter Earth's atmosphere and burn up from friction.
The stunning estimates of as many as 10,000 meteors during the 1-hour
storm are based on prior meteor storms that have occurred when the comet
has returned to Earth during the past 2 centuries.
Because the comet has a 33-year period, the last shower was on
November 17, 1966. A brief, 20 minute burst in meteor activity -- as
seen from the central and western United States lit up the skies with
40 meteors per second!
*****
The Space Telescope Science Institute is operated by the Association of
Universities for Research in Astronomy, Inc. (AURA) for NASA, under
contract with the Goddard Space Flight Center, Greenbelt, MD. The Space
Telescope is a project of international cooperation between NASA and the
European Space Agency (ESA).
This release and an illustration is available on the Internet at
http://oposite.stsci.edu/pubinfo/1998/40 and via links in
http://oposite.stsci.edu/pubinfo/latest.html.
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=SANA=
Дата: 12 ноября 1998 (1998-11-12)
От: Alexander Bondugin
Тема: Web Cam Lets You Peek Inside JPL As A New Radar System Is Built
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MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIFORNIA 91109. TELEPHONE (818) 354-5011
http://www.jpl.nasa.gov
Contact: Mary Hardin
INTERNET ADVISORY November 11, 1998
WEB CAM LETS YOU PEEK INSIDE JPL AS A NEW RADAR SYSTEM IS BUILT
A new web-based camera inside the Jet Propulsion
Laboratory's Spacecraft Assembly Facility allows the public to
watch the construction of the Shuttle Radar Topography Mission
(SRTM) hardware that will be launched on Space Shuttle Atlantis
in September 1999.
Live images of the radar antenna are accessible on the web
at:
http://www-radar.jpl.nasa.gov/srtm/webcam.html
SRTM evolved from the Space Radar Laboratory missions that
flew on two Space Shuttle flights in 1994. The effort is a
partnership between NASA and the Department of Defense's National
Imagery and Mapping Agency. In addition, the German and Italian
space agencies are contributing an experimental high-resolution
imaging radar system.
A key SRTM technology is radar interferometry, which
compares two radar images taken at slightly different locations
to obtain elevation or surface-change information. SRTM will
take two images at the same time -- one from the radar antennas
inside the shuttle's payload bay, the other from the radar
antennas at the end of a 60-meter (200-foot) mast extending from
the shuttle. Combining the two images produces a single three-
dimensional image.
The 3-D pictures -- called visualizations -- of Earth's
surface will be used by scientists for studies of flooding,
erosion, land-slide hazards, earthquakes, ecological zones,
weather forecasts and climate change. The data's military
applications include mission planning and rehearsal, modeling and
simulation. Other possible uses include optimizing locations for
cellular phone towers and improving topographic maps for
backpackers, firefighters, and geologists.
JPL manages SRTM for NASA's Office of Earth Science,
Washington, DC. JPL is a division of the California Institute of
Technology.
#####
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