Дата: 16 ноября 1998 (1998-11-16)
От: Alexander Bondugin
Тема: Ионный двигатель на Deep Space 1 проработал недолго
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Ионный двигатель на Deep Space 1 проработал недолго
[SpaceViews] Ионный двигатель, установленный на
экспериментальном космическом корабле Deep Space 1 (DS1) выключился
через 4,5 минуты после начала работы (10 ноября 1998 г., 14:30 по
восточному поясному времени). Причина остановки двигателя пока не
известна, попытки его повторного запуска остались безуспешными.
"Выключения" ионного двигателя уже наблюдались при испытаниях
на Земле и на космическом корабле на околоземной орбите, но DS1
предназначается для дальних космических экспедиций. Испытания такого
двигателя в дальнем космосе проводились впервые. Следует отметить,
что вся миссия Deep Space 1 носит экспериментальный характер, и
выяснение причин сбоя тоже является ее целью. Все остальные системы
DS1 работают нормально.
DS1 - это первая миссия про
Программе Hового Тысячелетия (New
Millennium Program), которая была
предпринята NASA для разработки и
полетных испытаний новых технологий,
которые могут быть использованы в
будущих космических экспедициях.
Кроме ионного двигателя, на DS1
проводятся испытания новых солнечных батарей, автономных систем
управления и различного научного оборудования.
Hа DS1 должны быть проведены не только испытания, но и
различные научные наблюдения. Этот корабль был запущен 24 октября
1998 г., в июле 1999 г. он должен долететь до астероида 1992 KD, а к 2001
г. , если будет решено продолжить миссию, может достигнуть двух комет.
Hо чтобы все это произошло, должен заработать ионный двигатель, так
как другого двигателя на DS1 нет. Hа снимке - Deep Space 1
Источник: InfoArt News Agency
Hа сегодня все, пока!
=SANA=
Дата: 16 ноября 1998 (1998-11-16)
От: Alexander Bondugin
Тема: Метеорный поток Леонид приближается
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Метеорный поток Леонид приближается
[NASA] Готовы мы к этому или
нет, но они приближаются -
метеоры потока Леонид (Leonid).
Утром 17 ноября частицы и
осколки кометы Темпеля-Таттла
(Tempel-Tuttle) врежутся в
атмосферу земли со скоростью
более 250 тыс. км/ч. Однако, это
не представляет большой
опасности для землян - только
некоторые из этих частиц упадут
на землю. Большинство из них
сгорит в атмосфере, и мы увидим
"падающие" звезды. По мнению специалистов нынешнее пришествие
метеорного потока Леонид (а это бывает раз в 33 года) будет самым ярким
явлением такого рода в этом столетии, так как его пиковая интенсивность
превысит 40 падающих звезд в секунду.
Большую часть своего времени
комета Темпеля-Таттла проводит на
окраине солнечной системы между
орбитами Сатурна и Урана. Раз в 33 года
она пролетает недалеко от Земли.
Последний раз это случилось 10 месяцев
назад в январе 1998 г. Комета прошла на
расстоянии 53,82 млн км от Земли и ее
легко можно было наблюдать в бинокль
или в небольшой телескоп. Hо комета не
приходит одна, ее сопровождает облако
льда и пыли, которые вылетают из ядра
кометы в результате ее нагрева
солнечными лучами. Эти осколки
продолжают двигаться вместе с кометой,
образуя укий вытянутый поток
метеоритных частиц. Метеорный поток Леонид вытянулся в длину на
несколько миллионов километров, а поперечные его размеры составляют
всего лишь 35 тыс. км.
В прошлый раз поток Леонид бомбардировал Землю в 1966 г., тогда
в некоторых местах можно было увидеть до 100 тыс. падающих звезд в
час (на снимке слева).
Hа этот раз лучше всего поток Леонид будет виден в Японии, Китае
и других регионах восточной Азии.
Hа снимке справа - поток Леонид в 1833 г. Источник: InfoArt News
Agency
Hа сегодня все, пока!
=SANA=
Дата: 16 ноября 1998 (1998-11-16)
От: Alexander Bondugin
Тема: Астрономы исследуют новые спектральные диапазоны
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Астрономы исследуют новые спектральные диапазоны
[NASA] В Аризоне планируется установить новый телескоп,
который будет наблюдать звезды в новом диапазоне длин волн -
коротком субмиллиметровом. До сих пор астрономы исследовали
излучение Вселенной в оптическом, ИК и радиодиапазонах.
Телескоп Heinrich Hertz Submillimeter Telescope (HHT) будет иметь
диаметр 10 м. Это совместный проект Обсерватории им. Стюарта
Университета Аризоны в Туксоне и Института Радиоастрономии им.
Макса Планка (Бонн, Германия).
Этой осенью сотрудники обсерватории уже провели тончайшую
настройку и юстировку всех 60 панелей, из которых состоит 10-метровое
зеркало рефлектора телескопа. Для этого были использованы сигналы
радиомаяка, установленного на околоземном спутнике. Hа этот процесс
ушло 3 недели, в результате чего точность установки рефлектора
составила 12 мкм (почти одна миллионная часть диаметра телескопа).
Для нового телескопа был разработан субмиллиметровый приемник
нового типа - болометр горячих электронов (Hot Electron Bolometer). С его
помощью будет регистрироваться излучение с длинами волн в диапазоне
от 300 до 1000 мкм.
Основной целью создания этого телескопа является исследования
холодных молекулярных облаков пыли и газа, находящихся на расстоянии
более 100 световых лет от Солнца. По мнению теоретиков, такие облака
образуются в результате взрыва сверхновой звезды, в результате которого
и была образована в свое время наша солнечная система. Исследования
таких облаков необходимы для лучшего понимания процесса образования
звезд. До сих пор не ясно, почему вокруг некоторых звезд образуются
планеты, а вокруг других - нет.
Источник: InfoArt News Agency
Hа сегодня все, пока!
=SANA=
Дата: 16 ноября 1998 (1998-11-16)
От: Alexander Bondugin
Тема: ESA's Spanish astronaut looking forward to Space Station (Forwarded)
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European Space Agency
Press Release No. 48-98
Paris, France 12 November 1998
ESA'S SPANISH ASTRONAUT LOOKING FORWARD TO SPACE STATION
ESA's first Spanish astronaut, Pedro Duque, "did a fantastic job in
orbit and has a great future in the space programme", declared Curt
Brown, the commander of the Space Shuttle Discovery which returned this
past weekend from its STS-95 mission. Brown was speaking during a press
conference on Sunday, the day after Discovery touched down at the
Kennedy Space Center in Florida.
Duque's STS-95 flight was the latest in a series of manned missions for
Europe that have been amassing valuable experience for the International
Space Station, the first element of which is to be launched next week.
The international crew also included the oldest ever astronaut John
Glenn (77) making his return to space 36 years after he became the first
American to orbit the Earth.
But Glenn was not the only crew member to go into the record books.
Duque became the first Spanish national to go into space and, born in
March 1963, more than a year after John Glenn's epic flight, he was also
the youngest crew member.
After returning to Earth on Saturday, Duque said he felt fine and would
like to return to space in the future as an ESA astronaut on the
International Space Station.
"This mission, and ESA's direct involvement in the Space Station, shows
that Europe is fully committed to exploiting space to the benefit of all
people on Earth," said Duque. "I would certainly like to be a part of
that." During the Space Shuttle flight of almost nine days, Duque's
responsibilities included monitoring the performance of ESA's scientific
experiment facilities, which carried experiments from scientists in
Belgium, Britain, France, Germany, Italy, Spain Sweden and Switzerland.
He also played a key role in the mission's medical experiments.
The mission was a final test for some of the ESA science facilities, and
experiments into the effects of weightlessness on various materials and
substances, that may be flown in Europe's Columbus laboratory of the
International Space Station.
Investigators are already analysing telemetry data sent from the
Shuttle, and samples from ESA's Biobox and the Advanced Protein
Crystallisation Facility (APCF) are now being prepared for post-flight
processing. The experiments in the other three ESA research facilities
(MOMO, AGHF and FAST) will be recovered from the Shuttle, as scheduled,
in late November or early December.
Note to editors:
The first element of the International Space Station is scheduled to be
launched from Baikonur, Kazakhstan, on 20 November.
ESA is one of five partners in the International Space Station
programme, the largest international technical project ever undertaken.
The other partners are the United States, Russia, Canada and Japan.
ESA is currently in discussion with the partners to have ESA astronauts
take part in missions to assemble the Space Station. Once the Space
Station is operational, one or two European astronauts will board it
each year for up to three months. Working as part of the six or
seven-member crew, they will conduct scientific research, monitor
experiments and contribute to general Space Station duties.
Andrew Yee
ayee@nova.astro.utoronto.ca
Hа сегодня все, пока!
=SANA=
Дата: 16 ноября 1998 (1998-11-16)
От: Alexander Bondugin
Тема: STARDUST Arrives At Kennedy Space Center For Launch Preparations
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MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
http://www.jpl.nasa.gov
Contact: Mary Beth Murrill
FOR IMMEDIATE RELEASE November 12, 1998
STARDUST ARRIVES AT KENNEDY SPACE CENTER FOR LAUNCH PREPARATIONS
NASA's Stardust spacecraft, designed to fly to a comet,
collect a sample and return it to Earth, has arrived at the
Kennedy Space Center, FL, to begin pre-launch processing.
Launch aboard a Delta 7426 rocket is currently targeted for
February 6, 1999 from Cape Canaveral Air Station.
Stardust will be the first spacecraft ever to bring cometary
material back to Earth for analysis by scientists worldwide.
Comets are believed to contain the original building blocks of
the planets and perhaps those of life itself. Early in Earth's
history, comets laden with water ice slammed into the planet,
maybe providing the source of our oceans. When Stardust returns
its pristine comet samples, scientists will be able to examine
for the first time the key ingredients of the original recipe
that created the planets.
The spacecraft was shipped from Lockheed Martin
Astronautics, Denver, CO, aboard a C-17 aircraft and landed at
Kennedy Space Center this morning. Stardust is being built
Lockheed Martin Astronautics and is managed by NASA's Jet
Propulsion Laboratory, Pasadena, CA. The principal investigator
of the mission is space particle scientist Dr. Donald Brownlee of
the University of Washington. Dr. Kenneth Atkins of JPL is the
project manager.
Stardust's main objective is to collect and bring to Earth
particles flying off the nucleus of Comet Wild-2 in January 2004.
It will also bring back samples of interstellar dust including
the recently discovered dust streaming into the solar system from
other stars. The spacecraft will send back pictures of Wild-2,
count the comet particles striking the spacecraft, and produce
real-time analyses of the composition of the material coming off
the comet.
A unique substance called aerogel is the medium that will be
used to catch and preserve comet samples. When Stardust swings
by Earth in January 2006, the samples encased in a reentry
capsule will be jettisoned and parachute to a pre-selected site
in the Utah desert.
The length of the Stardust main bus is 1.7 meters (5.5
feet), about the size of an average office desk. The spacecraft
weighs 385 kilograms (849 pounds). Among the processing
activities to be performed are installation and testing of the
solar arrays, final installation and testing of some spacecraft
instruments followed by an overall spacecraft functional test.
The spacecraft can then be fueled and mated to the Star 37 solid
propellant upper-stage booster.
Meanwhile, at Launch Complex 17, the Delta II rocket will be
undergoing erection and pre-launch checkout by Boeing. The first
stage is scheduled to be installed into the launcher on January
5, 1999. Four solid-rocket boosters will be attached around the
base of the first stage the next day. The second stage will be
mated atop the first stage on January 8, and the spacecraft
fairing will be hoisted into the clean room of the pad's mobile
service tower January 11.
Stardust will be transported to Complex 17 on January 28 for
hoisting aboard the Delta rocket on Pad A and mating to the
second stage. After the spacecraft undergoes state of health
checks, the fairing can be placed around it three days later.
Launch is currently targeted for February 6 at 4:08 p.m. EST.
The 20-day launch opportunity ends February 25.
Stardust is the fourth under NASA's Discovery Program of
low-cost science missions, following Lunar Prospector, Mars
Pathfinder and the Near Earth Asteroid Rendezvous (NEAR). The
goal of NASA's Discovery Program is to launch many smaller
missions with shorter development time that perform focused
science at lower cost.
JPL is a division of the California Institute of Technology,
Pasadena, CA.
#####
NOTE TO EDITORS: Images to accompany this release are
available on the web at:
http://www.ast.lmco.com/frameset.shtml?top=Media_Gallery,content=gallery_stard
ust
Hа сегодня все, пока!
=SANA=
Дата: 16 ноября 1998 (1998-11-16)
От: Alexander Bondugin
Тема: Discovery of a Young Near-By Supernova Remnant (Forwarded)
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Max Planck Institute for Extraterrestrial Physics
Garching/Germany
Contact: Bernd Aschenbach
Phone: +49-89-3299-3561 Fax: +49-89-3299-3569
13-11-98
Discovery of a Young Near-By Supernova Remnant
Young supernova remnant close to Earth discovered in hard X-rays towards the
edge of the "Vela" supernova remnant confirmed by detection of g-ray lines
from titanium-44
X-ray astronomers and g-ray astronomers of the Max Planck Institute for
Extraterrestrial Physics in Garching/Germany, have discovered a young
supernova remnant which is exceptionally close to Earth (Nature, Vol. 396,
12 November 1998). The remnant is just 700 light years away and it was
created about 700 years ago when a star exploded in the southern sky in
the constellation Vela ("sail").
"Our analysis shows that this is the nearest supernova remnant to have
occurred during recent human history; other similarly close remnants in the
Milky Way are of age of at least 10.000 years and more", Dr. Bernd Aschenbach
from the Garching Max Planck Institute explains. "Now, it is up to optical
astronomers and radio astronomers to confirm and extend our results."
The discoveries are being reported in two separate contributions in
"Nature's" issue of November 12, 1998, volume 396. The data on which these
discoveries rest have been taken with the German X-ray astronomy satellite
ROSAT, which has been developed and built under the direction of the
Garching Max Planck Institute, and by the COMPTEL instrument, built by an
international collaboration under the leadership of the Max Planck Institute
as well, on board of the U.S. American g-ray astronomy Observatory "COMPTON".
During the first all-sky survey with imaging X-ray telescopes also the Vela
constellation has been mapped by ROSAT. This is a region in the sky well
known to astronomers. In soft X-rays the Vela region is dominated by a huge
and bright supernova remnant, the Vela supernova remnant, with a diameter of
almost 200 light years, which still continues to expand at supersonic speed.
More than 10.000 years ago a star exploded as a gigantic supernova and it
gave rise to the clouds of hot gas which we see today. (Outside of the
boundary of the explosion cloud Dr. Bernd Aschenbach has discovered numerous
fragments of the progenitor star, a result which has been published in
"Nature" in March 1995.)
When Dr. Aschenbach was analysing the Vela supernova remnant in a way
differing from standard software routines developed for ROSAT, in particular
by extracting only the highest energy photons accessible with ROSAT, the
image of the Vela supernova remnant changed drastically. For photon energies
greater than 1300 electron volts the soft X-rays of the Vela supernova
remnant had disappeared almost completely and a previously unknown, fairly
circular emission region of about 2 degrees diameter, which is about four
times the size of the full moon, emerged at the south-east corner of the
Vela remnant (c.f. the pictures attached).
"We were stunned; there is no way around, this is a new supernova remnant",
Dr. Aschenbach says enthusiastically. "There are no other X-ray sources in
the sky we know of which show this sort of shape and brightness distribution,
except supernova remnants". The previously unknown object was named
"RX J0852.0-4622" according to the position in the sky.
Further analysis showed: "RX J0852.0-4622" is extremely hot at a temperature
of about 30,000,000 Kelvin. This means: "RX J0852.0-4622" is a very young
object, otherwise it would have cooled down to much lower temperatures
already. But because "RX J0852.0-4622" is young it could have reached the
angular extent of 2 degrees only if it is relatively close to Earth,
otherwise just a small patch of X-ray emission would have been visible.
"Detailed analysis and comparison with the well-studied remnant of the
supernova which occurred in the year 1006 demonstrate that the new
supernova remnant can not be significantly older than 1500 years and it
can not be located at distances greater than 1000 parsec or 3300 light
years", Dr. Aschenbach explains. "And the low X-ray surface brightness of
"RX J0852.0-4622" can be attributed to a low matter density of just 0.04
gas and dust particles per cubic-centimeter, surrounding the star before it
exploded. This is indeed low compared with standard values being about 20
times higher."
The case that "RX J0852.0-4622" is a supernova remnant was finally settled
by the g-ray astronomers. They specialize in studies of the g-ray emission
from radioactive decay of atomic nuclei. During the sudden death of a star
in a supernova, which takes a fraction of a second, matter density and
temperature in the star reach levels at which atomic nuclei change and
reformat. Most of the chemical elements including their isotopes are being
released from the star to the world at supernova explosions, without these
stellar ashes no life would have been possible. The matter expelled in the
supernova process is further being used, it is the "raw material" for
formation of the next generation of stars and planets.
Many isotopes are not stable; they decay at a variety of times scales,
which can be measured as "life-time" and which is a charateristic of each
individual isotope. Eventually only the known "natural" chemical elements
remain. Often the decay of an isotope is accompanied by the emission of
g-rays of very specific energies. These g-ray lines are as unique as a
finger-print for each radioactive isotope. Among other elements titanium-44
forms in a supernova explosion. It is produced exclusively during "silicon
burning" and it decays over scandium to calcium by emitting a g-ray line
of 1.156 million electron volt. The same group of g-ray astronomers had
discovered this line for the first time from the well known young galactic
supernova remnant "Cassiopeia A" already back some years ago.With the
discovery of the titanium-44 g-ray line now from "RX J0852.0-4622" it was
clear: "RX J0852.0-4622" is a young closeby supernova remnant.
Despite the fact that the production yield of titanium-44 in
"RX J0852.0-4622" is not known -- it is being produced in every type of
supernova but at different rates -- the g-ray measurements could be used to
further constrain the age and distance of "RX J0852.0-4622" making use of
the "life-time" of titanium-44. It is concluded that the supernova occurred
in the 13th century at a distance of about 700 light years from Earth. "This
is the first time that a previously unknown supernova remnant has been found
by means of the titanium-44 g-ray line", Dr. Anatoli Iyudin from the Max
Planck Institute for Extraterrestrial Physics comments about this success.
Coming years are very likely to show further discoveries of supernova
remnants. In our Milky Way two to three stars in every 100 years are
expected to explode; this follows from a comparison with external galaxies.
But for the last 1000 years only seven remnants have been found so far. The
remaining supernovae and their remnants might have escaped detection because
the optical light might have gone lost in intervening interstellar gas and
dust clouds. Hard X-rays and g-rays are not blocked by these clouds, so that
the missing supernova remnants might be found soon by the instruments on
board of the next X-ray astronomy and g-ray astronomy satellites, which are
already being built and which are close to launch.
IMAGE CAPTION: [http://www.mpg.de/news34_98.htm]
Figure 1: At X-ray photon energies of more than 1300 electron volts a new
X-ray source of circular shape emerges at the lower-left corner of the "Vela"
supernova remnant; picture taken by the ROSAT X-ray astronomy satellite.
X-ray astronomers and g-ray astronomers of the Max Planck Institute for
Extraterrestrial Physics (MPE) have demonstrated that this new source is a
young, previously unknown remnant, which has been borne in a supernova event
at a distance of about 700 light years just 700 years ago. The white patch
in the upper right shows the bright supernova remnant "Puppis-A", which is
far behind the "Vela" supernova remnant and is unrelated to it. Photo by Max
Planck Society/MPE.
Figure 2: Two ROSAT X-ray images of the same region of the sky: The left
hand image shows that the soft X-ray emission of the "Vela" supernova remnant
taken for energies between 100 and 2400 electron volts dominates the region
and outshines everything else except the very bright supernova remnant
"Puppis-A" towards the upper right corner, which however lies behind and is
not related to "Vela". Picking just the X-ray photons with energies greater
than 1300 electron volts shows that "Vela" is soft, i.e. no "hard" X-ray
photons are left; and the new supernova remnant with a diameter of two
degrees, which the X-ray astronomers and g-ray astronomers of the Max Planck
Institute have discovered, can clearly be seen in the lower left part. Photo
by Max Planck Society/MPE.
Figure 3: The image taken in the light of the 1.156 million electron volts
g-ray line shows a clear concentration of titanium-44 in the area, which
includes the X-ray object "RX J0852.0-4622" discovered by ROSAT. The g-ray
line image has been produced from data taken with the COMPTEL instrument
which was built by an international collaboration under the leadership of
the Max Planck Institute for Extraterrestrial Physics. Because titanium-44
is exclusively produced in supernovae explosions there was no doubt for the
X-ray astronomers and the g-ray astronomers the new object is a previously
unknown supernova remnant. Photo by Max Planck Society/MPE.
Andrew Yee
ayee@nova.astro.utoronto.ca
Hа сегодня все, пока!
=SANA=
Дата: 16 ноября 1998 (1998-11-16)
От: Alexander Bondugin
Тема: Mars Surveyor 98 Update - November 13, 1998
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1998 MARS SURVEYOR PROJECT STATUS REPORT
November 13, 1998
John McNamee
Mars Surveyor 98 Project Manager
Mars Climate Orbiter:
Orbiter launch processing activities are proceeding on schedule in the
Spacecraft Assembly and Encapsulation Facility (SAEF-2) facility at
Kennedy Space Center (KSC) with launch vehicle 3rd stage mate 11 days away
and launch 27 days away. Mission system testing of the
cruise/trajectory correction maneuver flight sequence was run
successfully. This completes the planned sequence verification testing
on the orbiter vehicle. Power on/stray voltage testing and the final
ordnance electrical mate was completed. The decision was made to pull
the flight Pyro Initiation Unit (PIU) immediately following spin
balance for rework to eliminate the potential for latchup as occurred
in mission system testing of the launch/initialization sequence. Cause
of the PIU anomaly is due to sensitivity of programmable logic device
inside the PIU to residual voltages on the power input prior to power
up. This condition can result in a latch up during the power up
sequence. The residual voltage has been tracked to a design feature
within the Power Distribution and Drive Unit (PDDU) power switches. The
unit will be returned to the vehicle on November 21.
The JPL Director's Mission Readiness/ LMA President's Reviews were
conducted in Denver. The orbiter was found to be ready for launch
pending successful completion of planned activities.
Mars Polar Lander:
Lander launch processing activities are proceeding on schedule in the
SAEF-2 facility at KSC with launch vehicle 3rd stage mate 32 days away
and launch 51 days away. Mission system testing of the entry, descent,
and landing phase (both 1"g" and scripted attitude) was completed
successfully. The Deep Space 2 (DS2) microprobes arrived at KSC and were
installed on the lander cruise stage without incident. The decision was
made to pull the flight Pyro Initiation Unit (PIU) immediately following
mission system testing of the cruise sequence for rework to eliminate
the potential for latchup as occurred in mission system testing of the
orbiter launch/initialization sequence. Cause of the PIU anomaly is due
to sensitivity of programmable logic device inside the PIU to residual
voltages on the power input prior to power up. This condition can
result in a latch up during the power up sequence. The residual voltage
has been tracked to a design feature within the Power Distribution and
Drive Unit (PDDU) power switches. The unit will be returned to the
vehicle on November 19.
For more information on the Mars Surveyor 98 mission, please visit
our website at:
http://mars.jpl.nasa.gov/msp98
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=SANA=
Дата: 16 ноября 1998 (1998-11-16)
От: Alexander Bondugin
Тема: NASA's Next Missions To Mars To Be Featured In Two Lecture
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MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
http://www.jpl.nasa.gov
Contact: Diane Ainsworth
FOR IMMEDIATE RELEASE November 13, 1998
NASA's NEXT MISSIONS TO MARS TO BE FEATURED IN TWO LECTURES
Norman Haynes, manager of the Jet Propulsion Laboratory's
Mars Exploration Program, will present details of NASA's next set
of missions to Mars -- the 1998 Mars Climate Orbiter and Mars
Polar Lander -- in a free public lecture to be held November 19
at JPL and November 20 at Pasadena City College's Forum, both at
7 p.m. Seating is limited and available on a first-come, first-
served basis.
"Going Back to Mars: The Mars '98 Missions Revisit the Red
Planet," is part of the monthly von Karman Lecture Series
sponsored by JPL.
Part of NASA's long-term program of Mars robotic
exploration, the two 1998 missions will launch in December 1998
and January 1999. Both spacecraft are scheduled to arrive at
Mars in December 1999 to advance scientists' knowledge of Mars'
climate history and the planet's current water resources by
digging into the enigmatic layered terrain near the south pole
for the first time.
Haynes, an aeronautical engineer, has served on a variety of
space flight missions beginning with the 1964 Mariner 4 and 5
Mars flybys. More recently he served as deputy assistant
director of the former Flight Projects Office, manager of the
Voyager Project to the outer planets and manager of science and
mission design for the Galileo Project. Prior to his current
position, Haynes was director of the Telecommunications and
Mission Operations Directorate.
He holds a bachelor of science degree in aeronautical
engineering from Purdue University and a master's degree in
aeronautical engineering from the University of Southern
California.
More information about JPL's von Karman Lecture Series is
available on the Internet at http://www.jpl.nasa.gov/lecture/, or
by calling (818) 354-5011. JPL is a division of the California
Institute of Technology.
#####
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=SANA=
Дата: 16 ноября 1998 (1998-11-16)
От: Alexander Bondugin
Тема: Sky & Telescope News Bulletin - November 13, 1998
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SKY & TELESCOPE'S NEWS BULLETIN
NOVEMBER 13, 1998
IT'S LEONID TIME
Astronomical anticipation will peak Monday and Tuesday along with the
Leonid meteor shower, as astronomers around the world will watch, wait, and
wonder. Astronomers predict that an intense shower, last seen in 1966, may
hit some time around 17 to 21 hours Universal Time November 17th. That's
noon to 4 p.m. Eastern time. If so, Japan and the western Pacific Rim
(where the local date will be the morning of November 18th) will be
positioned to see the show. North America and Europe will be on the side of
the world facing away from the meteors and will miss out. However, if the
prediction is as much as 12 hours off one way or the other, any region of
the world could be favored. The strongest part of the shower is expected to
last no more than an hour or so. Furthermore, the shower could still put on
a good show on the mornings before and after the peak. The time to be
watching is from 1 or 2 a.m. your local time until dawn; that's when your
side of the world will be facing into the oncoming meteors.
Australian observer Robert McNaught explains that at least two observing
teams on the ground will be hoping to photograph the "radiant glow" as the
Earth crosses the orbital plane of the Leonid's parent comet
55P/Tempel-Tuttle. At that time, observers will be "looking down the tube"
of cometary debris, which may become faintly visible as the particles
reflect sunlight. McNaught will attempt to image the glow with a large
Schmidt camera, as will a team of Japanese astronomers.
Some professional astronomers have more elaborate plans. Avoiding any
clouds is the goal of two research aircraft that will be circling above
Japan hoping to record the possible meteor "storm." The planes will carry
various equipment including high-definition TV cameras.
Controllers of many satellites in Earth orbit will be taking extra
precautions against the cosmic debris. The Hubble Space Telescope will be
aimed "downstream" from the incoming Leonid tide, but it won't be dormant.
The Space Telescope Science Institute announced Tuesday that Hubble will be
taking pictures of a distant quasar that's in just the right part of the
sky. NASA's Goddard Space Flight Center reports that many other spacecraft
will be reoriented to minimize the chances of damage. Some will have their
power reduced or shut off.
Check http://www.skypub.com/ for late details about any surge of Leonid
activity.
1,000TH PULSAR TALLIED
The University of Manchester announced today that astronomers using the
64-meter Parkes Radio Telescope in New South Wales, Australia, have
discovered the 1,000th pulsar in our galaxy. A "multibeam" receiver
installed on the telescope in early 1997 has allowed the astronomers from
England, Australia, United States, and Italy to find pulsars much faster
than before. On average, they have snagged a new pulsar in every hour of
observing. The researchers have already found more than 200 pulsars and
expect to find another 600 more before the survey ends. The first pulsar
was discovered on November 28, 1967, at Mullard Radio Astronomy Observatory
in Cambridge, England.
COMET GIACOBINI-ZINNER ENTERS CAPRICORNUS
Observers report that Comet 21P/Giacobini-Zinner is hanging in there at
between magnitude 8.5 and 9. This week the comet leaves Aquila and enters
Capricornus and lies about 20 to 40 degrees above the southwestern to
western horizon, depending on your latitude, at the end of evening
twilight. For a finder chart, see page 107 of the November *Sky &
Telescope,* or visit
http://www.skypub.com/sights/comets/Giacobini/gz_1998.html. Here are
positions for Comet Giacobini-Zinner for 0 hours Universal Time (2000.0
coordinates) for the coming week:
R.A. Dec.
November 14 19h 55m -10.4 deg.
November 16 20h 04m -11.4 deg.
November 18 20h 14m -12.4 deg.
THIS WEEK'S "SKY AT A GLANCE"
Some daily events in the changing sky, from the editors of SKY &
TELESCOPE.
NOV. 15 -- SUNDAY
* Jupiter's Great Red Spot should cross the planet's central meridian
(the imaginary line down the center of Jupiter's disk from pole to pole)
around 10:30 p.m. Eastern Standard Time. Lately the spot has been pale
orange-tan with a darker outline. For a list of all predicted Red Spot
transit times, see http://www.skypub.com/sights/moonplanets/redspot.html.
* Jupiter's moon Io crosses the planet's face from 7:09 to 9:24 p.m. EST.
The bright little moon will be hard to see against the bright background of
Jupiter -- but Io's tiny black shadow follows it across the planet from
8:23 to 10:37 p.m. EST. A small telescope should show the shadow.
NOV. 16 -- MONDAY
* Watch for a possible great Leonid meteor storm late tonight! (early on
the morning of the 17th). The time to be watching is from 1 or 2 a.m. your
local time until dawn; that's when your side of the world will be facing
into the oncoming meteors. Astronomers predict that an intense shower, last
seen in 1966, may hit some time around 17:00 to 21:00 Universal Time
November 17th. If so, Japan and the western Pacific Rim (where the local
date will be the morning of November 18th) will be positioned to see the
show; North America and Europe will be on the side of the world facing away
from the meteors and will miss out. However, if the prediction is as much
as 12 hours off one way or the other, any region of the world could be
favored. The strongest part of the shower is expected to last no more than
an hour or so.
NOV. 17 -- TUESDAY
* Watch again for the Leonids late tonight (during the early hours of
Wednesday morning) -- especially if no intense shower has been reported
yet! Listen to the news, or check http://www.skypub.com/ for updates.
NOV. 18 -- WEDNESDAY
* New Moon (exact at 11:27 p.m. EST.)
* Jupiter's Red Spot transits the planet's central meridian around 8:00
p.m. EST.
NOV. 19 -- THURSDAY
* Ceres, the largest minor planet (asteroid), is drifting in the Hyades
near Aldebaran in the late-evening sky this month. You can pick it up in
binoculars; it's about magnitude 7. Use the finder chart in the November
Sky & Telescope, page 109.
* Just after dusk, telescope users from the Deep South to the upper
plains states can try to time the asteroid 532 Herculina occulting
(covering and blacking out) a 9.8-magnitude star in southern Cetus. The
combined brightness of the star-and-asteroid image will drop by 1.7
magnitudes for up to 30 seconds around 8:04 p.m. Eastern Standard Time,
7:04 p.m. Central Standard Time. Herculina has been suspected of having a
satellite, based on somewhat controversial occultation evidence from 1978,
so anyone in the region or eastward who can videotape a 10th-magnitude star
should try to record the star's behavior for at least several minutes
before and after the predicted time. See the finder chart in the November
Sky & Telescope, page 112, or
http://www.skypub.com/sights/occultations/occultations.html.
NOV. 20 -- FRIDAY
* Another asteroid occultation: An 8.4-magnitude star in northern Orion
should be covered by 45 Eugenia for telescope users somewhere from the
Midwest through the Northeast for up to 18 seconds around 7:53 p.m. EST,
6:53 CST. See the finder chart in the November Sky & Telescope, page 112,
or http://www.skypub.com/sights/occultations/occultations.html.
* Jupiter's Red Spot transits around 9:39 p.m. EST.
NOV. 21 -- SATURDAY
* Comet Giacobini-Zinner is at perihelion, the closest point in its orbit
to the Sun. It should be glowing dimly at 9th magnitude in western
Capricornus this week, detectable in a medium-sized amateur telescope right
after dark. Use the finder chart in the November Sky & Telescope, page 107,
or at http://www.skypub.com/sights/comets/Giacobini/gz_1998.html.
THIS WEEK'S PLANET ROUNDUP
MERCURY is just above the southwest horizon about 30 minutes after sunset.
Use binoculars.
VENUS is hidden in the glare of the Sun.
MARS shines well up in the southeast before and during dawn. It's at the
Leo-Virgo border.
JUPITER is the big, brilliant "star" high in the south during the evening.
You can't miss it! Jupiter moves to the southwest in late evening and sets
after midnight.
SATURN is the bright yellow "star" far to Jupiter's lower left after dusk,
directly left of Jupiter by midevening, and to Jupiter's upper left as the
evening grows late. The two planets appear 40 degrees apart (about 4
fist-widths at arm's length), on opposite ends of Pisces.
URANUS and NEPTUNE, magnitudes 5.8 and 7.9 respectively, are in (or very
near) Capricornus in the south-southwest just after dark. See the finder
chart for them in the September Sky & Telescope, page 110, or at
http://www.skypub.com/sights/moonplanets/urnepplu.html.
PLUTO is hidden in the sunset.
(All descriptions that relate to the horizon or zenith are written for the
world's midnorthern latitudes. Descriptions that also depend on longitude
are for North America. Eastern Standard Time, EST, equals Universal Time
minus 5 hours.)
More details, sky maps, and news of other celestial events appear each
month in SKY & TELESCOPE, the essential magazine of astronomy. See our
enormous Web site at http://www.skypub.com/. Clear skies!
SKY & TELESCOPE, P.O. Box 9111, Belmont, MA 02478 * 617-864-7360 (voice)
Copyright 1998 Sky Publishing Corporation. S&T's Weekly News Bulletin and
Sky at a Glance stargazing calendar are provided as a service to the
astronomical community by the editors of SKY & TELESCOPE magazine.
Widespread electronic distribution is encouraged as long as these
paragraphs are included. But the text of the bulletin and calendar may not
be published in any other form without permission from Sky Publishing
(contact permissions@skypub.com or phone 617-864-7360). For updates of
astronomical news, including active links to related Internet resources,
are available via SKY & TELESCOPE's site on the World Wide Web at
http://www.skypub.com/.
In response to numerous requests, and in cooperation with the Astronomical
League (http://www.mcs.net/~bstevens/al/) and the American Association of
Amateur Astronomers (http://www.corvus.com/), S&T's Weekly News Bulletin
and Sky at a Glance are available via electronic mailing list too. For a
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the body of the message.
SKY & TELESCOPE, the Essential Magazine of Astronomy, is read by more than
200,000 enthusiasts each month. It is available on newsstands worldwide.
For subscription information, or for a free copy of our catalog of fine
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custserv@skypub.com. WWW: http://www.skypub.com/. Clear skies!
Hа сегодня все, пока!
=SANA=
Дата: 16 ноября 1998 (1998-11-16)
От: Alexander Bondugin
Тема: Aerospace Corporation Analysis Helps Confirm Unexplained "Pull" on Spa
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The Aerospace Corporation
2350 E. El Segundo Blvd.
El Segundo, CA 90245-4691
Mail: P.O. Box 92957
Los Angeles, CA 90009-2957
(310) 336-5000, Fax: (310) 336-7055
October 26, 1998
Aerospace Analysis Helps Confirm Unexplained "Pull" on Spacecraft
The Aerospace Corporation has helped confirm a tiny and unexplained
acceleration of NASA spacecraft toward the sun and ruled out a number of
possible causes. The principal investigator at Aerospace also has explained
what the company believes to be the most likely cause.
The anomalous acceleration, resulting from a pull about 10 billion times
smaller than the acceleration we feel from Earth's gravitational pull, was
confirmed through detailed analyses of radio data from Pioneer 10, Pioneer
11 and Ulysses spacecraft.
The Aerospace Corporation was brought into an investigation of the
phenomenon by researchers at JPL and Los Alamos National Laboratory.
Preliminary data examined by these researchers needed to be confirmed.
A JPL researcher, John Anderson, first saw the effect in 1980, but until
he had accumulated data over the next 15 years, he could easily dismiss
it as the result of systematic errors. "Like a lot of problems in astronomy,
many years of observation are needed," Anderson said.
Another researcher, Michael Nieto of Los Alamos, has long been interested
in the possibility that gravity works differently on antimatter than on the
familiar matter that makes up our everyday world. This led him to consider
how well we understand gravity's influence on normal matter and whether
studies of the motions of comets or spacecraft could be used to identify
any deviations from the expected influence of gravity.
Anderson and Nieto began working together along with colleagues from
their labs. About three years ago the researchers redoubled their efforts to
analyze the spacecraft motions and possible contributing perturbations by
asking Aerospace to check their work.
Philip Laing, engineering specialist and principal investigator, working with
consultant Anthony Liu of Astrodynamic Sciences Co., Los Angeles, under
a NASA Office of Space Science grant, conducted an independent analysis of
data using a computer program developed by Aerospace. Laing said they been
have able to rule out these possible causes of the anomalous acceleration.
* Errors in JPL's orbital determination software
* Gravity of the Kuiper belt and gravity from the galaxy
* Errors in the planetary ephemeris
* Errors in the values of the Earth's orientation, precession, and
nutation
* Nongravitational effects from solar pressure and attitude control
maneuvers
* Solar wind and interplanetary medium
* Nominal thermal radiation and plutonium half-life
* Drifting clocks, general relativity, and the speed of gravity
* Hardware problems at the tracking stations
After exhausting the list of explanations deemed most plausible, the
researchers examined possible modifications to the force of gravity as
explained by Newton's Law -- with the sun being the dominant gravitational
force -- or the possible influence or nonordinary, or "dark" matter. The
dark-matter explanation falls short, because so much matter would have
been required to create the accelerations it would have affected the
motions of other bodies in the solar system.
The researchers concluded that if the anomalous radial acceleration acting
on spinning spacecraft is gravitational in origin, it is not universal. It
would have to affect bodies with masses of a thousand kilograms or so more
than bodies the size of planets.
The researchers noted that NASA's planned mission to Pluto, which would
include more accurate tracking systems, may provide additional, high-quality
data for investigating this mystery. In addition, Pioneer 10 is still a
potential source of data because its transmitter is still functioning. The
team also is conducting more detailed analyses of Ulysses' swing around the
sun. The Pluto mission is scheduled for early in the 21st century.
"Clearly, more analysis, observation, and theoretical work are called for,"
the researchers concluded.
Laing said the research has generated considerable interest among physical
scientists and that a number of these have offered to participate in the
research. They are intrigued by the fact that while the acceleration is tiny
and has no significant effect on NASA missions, it holds great interest
because no explanation based on conventional physics and understanding has
been found. The effect is so persistent that it could indicate some physics
not considered in previous attempts to explain the motions of bodies in the
universe.
The research by Laing, Liu and their colleagues at JPL and Los Alamos was
published Oct. 5 in Physical Review Letters, a publication of the American
Institute of Physics. Reports also have been published in The New York Times
and New Scientist magazine.
In an interview with Scientific American Oct. 13, Laing stated that the The
Aerospace Corporation's view is that the anomalous acceleration is most
likely due to gas leaks. This possible cause he attributed to imperfect
valves. Laing explained that this conclusion is supported by tracking data
not available in earlier studies. Thermal radiation or new physics are
possible but less likely causes, Laing said.
Andrew Yee
ayee@nova.astro.utoronto.ca
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=SANA=
Дата: 16 ноября 1998 (1998-11-16)
От: Alexander Bondugin
Тема: Cassini Update - November 13, 1998
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Cassini Significant Events
for 11/06/98 - 11/12/98
Spacecraft Status:
The most recent Spacecraft status is from the DSN tracking pass on Monday,
11/09, over the Goldstone tracking station. The Cassini spacecraft is in
an excellent state of health and is executing the Cruise 10 sequence
normally. The speed of the spacecraft can be viewed on the "Where is
Cassini Now?" web page (http://www.jpl.nasa.gov/cassini/today/).
Spacecraft Activity Summary:
On Friday, 11/06, routine maintenance was performed on the Solid State
Recorder (SSR-B) flight software partitions.
On Saturday, 11/07, Part 1 of the Cruise 11 sequence was successfully
uplinked to the spacecraft.
On Monday, 11/09, a housekeeping activity was performed which reads out a
set of AACS Attitude Estimator measurements not available in regular
engineering telemetry, and the Solid State Recorder (SSR-B) record and
playback pointers were reset
Upcoming events:
Activities scheduled for the week of 11/13-11/19 include initiation of the
C11 sequence, SSR Pointer Reset on 11/15, and update active to Spacecraft
Vector on 11/18. Ranging passes will occur on 11/13 and 11/15.
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=SANA=
Дата: 16 ноября 1998 (1998-11-16)
От: Alexander Bondugin
Тема: New Mars Plan Targets Sample Return
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From The "JPL Universe"
November 13, 1998
New Mars plan targets sample return
International effort to pave way for robotic colonies by 2010
By DIANE AINSWORTH
A new architectural blueprint for international robotic exploration of
Mars, resulting in the return of several samples of Martian material to
Earth by 2008 and founding of the first permanent robotic colonies by the
end of that decade, has been launched by NASA and its international
partners in space exploration.
"This plan paves the way for the return of as many as four samples of
Martian material from four different sites by 2011, and will lead to the
establishment of the first robotic outposts and, eventually, human colonies
on Mars," said Norman Haynes, Mars Exploration Program director at JPL.
Under a new plan drafted by NASA and its French, Italian and European
counterparts, the consortium of spacefaring nations will begin development
of affordable spacecraft and innovative new technologies to obtain in-situ
measurements and samples of Martian material in preparation for human
exploration of the planet. The plan calls for construction of a fleet of
affordable launch vehicles, orbiters, landers, rovers and Mars ascent
vehicles designed to wage an all-out effort to begin returning samples of
the Martian regolith as early as April 2008.
"This plan lays out the whole framework for our next quantum leap in Mars
exploration," said Dr. Charles Elachi, JPL's Space and Earth Sciences
Program director and head of the architecture study. "The establishment of
the first permanent robotic colonies on Mars, capable of harnessing the
planet's natural resources to build a technology base for space flight to
and from the planet and biospheres for human settlements well within the
lifetimes of our grandchildren, is the most exciting prospect awaiting us
as a global community."
The new Mars architecture plan, which is currently being refined by NASA
and participating space agencies, underscores the roles and
responsibilities of the four space agencies in formulating an integrated,
international roadmap for the exploration of Mars.
According to Haynes, the study focuses on robotic surface activities during
the early launch opportunities beginning in 2001 through 2011. Many of the
early missions will focus on studies of the Martian surface involving
science payloads designed to conduct chemical analyses of rocks and soils,
obtain rock core samples and tap subsurface water reservoirs and other
natural resources that could be used to manufacture propellants to fuel
sample-return vehicles.
Work on the architectural redesign began in June. Eight "tiger teams" of
experts from the international scientific community, led by Elachi and Dr.
Frank Jordan, manager of JPL's Mars Program Planning and Architecture
Office, were formed to address issues of spacecraft design, innovative
technologies and science goals for missions beginning in 2003, as well as
for achieving the overall goals of the long-range Mars Surveyor Program.
Recom-mendations were presented to NASA Administrator Daniel Goldin on
Sept. 24 and, subsequently, approved for implementation.
New requirements for the 2001 Mars missions, brought about earlier in the
year by Congressional markups of the fiscal year 1999 NASA budget, prompted
the redesign effort. The Mars 2001 project went to work to hammer out a
compromise of scientific instruments on the proposed orbiter, lander and
rover to meet new budget and spacecraft mass requirements.
Under the current mission architecture, the Mars 2001 lander will be
equipped with a robotic arm and descent camera to explore materials buried
below the Martian surface. The spacecraft will also carry a panoramic
camera and mini-thermal emission spectrometer, which was part of the
originally proposed payload, and a Moessbauer spectrometer designed to
study Martian materials.
Three human exploration experiments developed under NASA's Human
Exploration and Development of Space (HEDS) Enterprise are also included in
the lander payload: the Mars Environmental Compatibility Assessment Project
experiment, an instrument to investigate potentially hazardous atmospheric
conditions that could affect human exploration; a Mars propellant
production experiment to explore the feasibility of using atmospheric
carbon dioxide to manufacture fuel for return vehicles; and a Mars
radiation experiment to detect hazardous amounts of the substance in the
Martian atmosphere.
In addition, a simpler, lighter-weight rover modeled after Mars
Pathfinder's Sojourner rover was chosen to replace the original, more
sophisticated and costly roving vehicle. The new rover, nicknamed Marie
Curie, will carry an alpha proton X-ray spectrometer similar to the
spectrometer carried on the Sojourner rover to study the chemical
composition of rocks and surface soils and a second Mars radiation
experiment to detect harmful levels of radiation on the Martian surface.
NASA will begin the series of sample-return mission in 2003, with launch of
a lander and a rover that will spend several months searching for and
collecting rock and soil samples, said Dr. Daniel McCleese, chief scientist
and manager of the Office of Strategy and Science Programs for JPL's Mars
Exploration Directorate. The roving vehicle will return the sample to a
new, low-cost, low-mass Mars ascent vehicle.
Conceived by Brian Wilcox of the JPL Mars Exploration Technology
Development Division, the Mars ascent vehicle is the centerpiece of the
program's overarching, short-term goal to explore the Martian subsurface
robotically. The vehicle is a simple rocket with with a three-stage,
spin-stabilized ascent system, solid-rocket motors, minimal onboard
guidance and virtually no moving parts. The launcher, which weighs about
100 kilograms (220 pounds) or less than 30 percent of previous Mars ascent
vehicle designs, will place soil and rock sample canisters into a low-Mars
orbit, where they will await pick-up by orbiters arriving at Mars beginning
in 2005.
NASA will also provide a Boeing Delta 3-class launch vehicle and an Earth
entry capsule comprised of a crescent-shaped heat shield and crushable foam
material that will shield the Martian soil and rock samples when they
plummet to the floor of a desert in Utah in spring 2008.
In partnership with the French space agency, Centre National d'Etudes
Spatiales (CNES), NASA will also work toward developing a small
"microspacecraft" weighing less than 200 kilograms (440 pounds) for
delivery to Mars during this launch opportunity, Elachi said. CNES has
agreed in principle to providing a piggyback ride to Mars on its Ariane 5
launch vehicle, which is capable of placing the Martian microspacecraft on
a geosynchronous transfer orbit above Earth. If flown, the miniature
spacecraft would use its own propulsion and gravity assists from the Moon
and Earth to gain enough momentum to reach Mars.
Another collaborative arrangement with the Italian space agency, Agenzia
Spatiale Italiana, will add a drill and other robotic elements to the 2003
Martian lander and those following in its footsteps. Additional robotic
elements will include radio relay equipment to support the European Space
Agency's proposed _Mars Express_ orbiter, which will be used for data
transmission from landers arriving at Mars in future years. The European
Space Agency also plans to supply a sounding radar for the mission.
In 2005, a single Ariane 5 launch vehicle carrying a duplicate of the 2003
lander, rover, Mars ascent vehicle and French orbiter will be launched to
Mars. The lander, with its companion rover and ascent vehicle, will land at
a different location, collect a second sample of Martian rocks and soils
and loft it into low-Mars orbit.
The orbiter will be inserted into a highly elliptical Mars orbit, aerobrake
to low-Mars orbit, rendezvous and dock with the 2003 orbiting sample
container and then rendezvous and dock with the 2005 sample. After 11
months in orbit, the spacecraft will fire its rocket engines to inject
itself and the two Earth entry capsules on an Earth-return trajectory. The
orbiter will target the two entry capsules carrying Martian samples onto
impact trajectories, deploy them and then deflect its own trajectory so
that it does not crash into Earth.
Two options are currently on the table with NASA and the French space
agency for inserting the 2005 orbiter into Mars orbit. The first option
would be to use propulsive maneuvers to lower and circularize the
spacecraft's orbit. The second option would be to use a technique called
"aerocapture," which is similar to aerobraking but would slow and directly
capture the spacecraft in orbit in one step, rather than gradually slowing
and lowering the spacecraft through a series of "walk-in" phases used in
the aerobraking strategy. With aerocapture, the orbiter would be able to
reach its final, circular mapping orbit within about one week instead of
approximately nine months.
If international participation and the budgetary outlook remain stable, a
total of six samples from six separate locations on the surface of Mars
will have been returned by 2013, Haynes said.
To realize this scenario, another Delta 3-class launch vehicle would be
used in 2007, carrying a lander, rover and Mars ascent vehicle. The samples
collected would be cached on orbit to await pick-up by the 2009 orbiter. In
2009, two launches using Delta 3-class launch vehicles would follow suit.
The orbiter would be the first vehicle to be launched, followed by a second
lander, rover and Mars ascent vehicle. A French orbiter would collect the
Mars samples from both the 2007 and 2009 landers and deploy them on return
trajectories to Earth. If successful, that mission scenario would be
repeated in 2011 and 2013.
Hа сегодня все, пока!
=SANA=
Дата: 16 ноября 1998 (1998-11-16)
От: Alexander Bondugin
Тема: MGS Aerobraking Update - November 12, 1998
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Mars Global Surveyor Aerobraking Status Report
Thursday, November 12 (DOY 313/19:00:00 to DOY 316/19:00:00 UTC)
Last Orbit Covered by this Report = 711
Total Phase I Aerobraking orbits accomplished = 180
Total Phase II Aerobraking orbits accomplished = 138
Total Science Phasing orbits accomplished = 290
Apoapsis altitude = 9583 km
Apoapsis altitude decrease since start of aerobraking = 44443 km
Periapsis altitude = 112.7 km
Current Orbit Period = 06:18:07
Orbit Period decrease since start of aerobraking = 38:41:26
Starting Phase II orbit period = 11:38:02
RECENT EVENTS:
The Mars Global Surveyor spacecraft continues Phase 2 aerobraking operations
in excellent health. Progress continues per plan as 17 minutes of orbit
period have been removed over the past 11 drag passes. The 6-orbit running
mean is currently 0.268 N/m2 which is above the 0.23 corridor control
trigger limit. The project has elected to gain a little orbit period margin
and allow the overshoot to occur for a short period. The 2 minute deficit
from the baseline plan has now been erased. One corridor control maneuver
was executed on the apoapsis of orbit 710 which raised the periapsis
altitude about 1/2 corridor.
Currently, sequence P708 is controlling the S/C activities. It will be
replaced early this evening with P712 which will control activities starting
with orbit 712 through orbit 715. The sequence contains command for orbits
716 and 717 as backup in case ground sequence generation problems occur. All
timing estimations continue to be well within the 232s, excessive fuel use
limit.
Subsystems continue to report excellent S/C health and performance. The -Y
solar array yoke has shown no change in structural performance. Stiffness
values have not been valid this period due to lack of sun light on the -Y
panel sun sensor during the drag pass. The system structural frequency has
been maintained at about 0.153 Hz. Attitude knowledge has been maintained
throughout the period with excellent star processing. The power subsystem
reports strong performance with 11.0 % maximum battery discharge depths each
orbit. There is now 13 minutes of primary charger margin. The minimum MOLA
laser temperature observed this period was 11.2°C during the corridor
control maneuver on orbit 710. The largest temperature increase due to
aero-heating seen was 68°C on the -Y solar array, cell side. The
telecommunications subsystem continues solid performance.
In the STL, re-validation of the Pop-Up maneuver contingency sequence has
been completed. Initial testing of the 2 am mapping flight software changes
is underway.
UPCOMING EVENTS:
Periapsis for Orbit 712 DOY317/00:21:07 UTC Through
Periapsis for Orbit 726 DOY320/13:45:32 UTC
(Note: MST = UTC-7 hours DOY317=11/13)
SPACECRAFT COMMANDING:
There were 9 command files radiated to the S/C during this period. The total
files radiated since launch is now 2963. These commands were sent in support
of the following activities:
Nominal drag pass sequences (P701, P705, P708)
Nominal corridor control maneuver sequences (A710)
Nominal star catalog and ephemeris file updates
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Дата: 16 ноября 1998 (1998-11-16)
От: Alexander Bondugin
Тема: Mars Global Surveyor Update - November 13, 1998
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Mars Global Surveyor
Project Status Report Overview
Prepared by Mars Surveyor Operations Project Manager
NASA Jet Propulsion Laboratory
Friday 13 November 1998
The Mars Global Surveyor spacecraft continues Phase 2 aerobraking operations
in excellent health. Progress continues per plan as 17 minutes of orbit
period have been removed over the past 11 drag passes. The 6-orbit running
mean is currently 0.268 N/m2 which is above the 0.23 corridor control
trigger limit. The project has elected to gain a little orbit period margin
and allow the overshoot to occur for a short period. The 2 minute deficit
from the baseline plan has now been erased. One corridor control maneuver
was executed on the apoapsis of orbit 710.
An operational readiness test was conducted for the Mars Polar Lander launch
and initial acquisition activities.
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Дата: 16 ноября 1998 (1998-11-16)
От: Alexander Bondugin
Тема: Space support will help European competitiveness and economic performa
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European Space Agency
Press Information Note No. 39-98
Paris, France 13 November 1998
The History of the European Space Agency - An International Symposium
Space support will help European competitiveness and economic performance
Europe's space programme can make a major contribution to improving Europe's
competitiveness and economic performance, according to Mr Antonio Rodota,
Director General of the European Space Agency. It can also contribute to UK
Prime Minister Tony Blair's vision of a 'people's Europe', he said. "We need
to convince Europeans that they have reasons to be proud of themselves and
of what they can achieve through the pooling of their talents and
resources".
Speaking at the Science Museum on Wednesday, during the opening by UK
Science Minister, Lord Sainsbury of a joint ESA and Science Museum
international symposium on the history of the European Space Agency, Mr
Rodota, said that European space cooperation had often been accompanied by
uncertainty, yet Europe's space programme continued to be pursued with a
large measure of success.
"Projects such as Ariane have come to symbolise the value of excellence and
of true European collaboration in high technology. The latest example is the
flawless final qualification flight of Ariane 5 on 21st October," he said.
The international symposium forms the culmination of the ESA History
Project, which has for the past eight years researched the history of
European space initiatives between 1964 and 1987. The symposium, which is
at the Science Museum on 12th and 13th November, brings together leading
players of that period. Speakers include former Government Ministers such as
Mr Michael Heseltine of the UK, Mr Hubert Curien of France and Mr Antonio
Ruberti of Italy.
Sir Neil Cossons, Director of the Science Museum, spoke of the importance of
space both to the Museum's visitors and to its research community. "Space is
the most popular topic of science amongst our visitors", he said.
"Understanding the history of the European space programme is vital to our
presentation of achievement and aspirations in space exploration."
Sir Neil announced that the Museum was planning a refurbishment of its
Exploration of Space gallery next year, thanks to contributions from Matra
Marconi and the British National Space Centre. "Visitors to the Science
Museum, from the UK, Europe, and across the world, expect us to present the
latest information about space science and technology in an inspirational
and accessible way," he told symposium delegates. "We are determined to
rise to that challenge".
Andrew Yee
ayee@nova.astro.utoronto.ca
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Дата: 16 ноября 1998 (1998-11-16)
От: Alexander Bondugin
Тема: Deep Space 1 Update - November 14, 1998
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MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
http://www.jpl.nasa.gov
DEEP SPACE 1 MISSION STATUS
November 14, 1998
Ground controllers returned Deep Space 1 to normal cruise
configuration Friday, November 13, two days after an event that
put the spacecraft into safe mode. The spacecraft is in
excellent condition, and the flight team will now resume testing
the dozen advanced technologies that the mission is flying.
The process of restoring normal cruise configuration
occupied about six hours Friday afternoon and early evening,
beginning at 2 p.m. PST. The spacecraft fired its thrusters to
turn it to regular cruise orientation, with one low-gain antenna
pointing at Earth. Ground controllers also commanded the
telecommunications system to return to sending data to Earth at a
higher rate of 9,480 bits per second; during the time that the
spacecraft was in safe mode, it switched to a slower rate of
2,100 bits per second. Several spacecraft devices that had been
turned off during the safe mode were turned back on.
With the return of normal cruise mode, the flight team will
resume validating the mission's advanced technologies. Early
next week, they expect to focus on the spacecraft's autonomous
navigation system and one of its advanced science instruments,
the Miniature Integrated Camera Spectrometer (MICAS). Toward the
end of next week, the team expects to work with the ion engine.
At that time they will probably attempt to restart the engine,
which shut itself down 4-1/2 minutes after it was turned on for
its first test Tuesday, November 10.
Also on Friday, the team obtained important new evidence to
help understand why devices used to deploy the spacecraft's solar
arrays were unexpectedly activated Wednesday, November 11, about
the same time that the safing event took place. The team was
able to replicate the event activating the solar array deployment
devices in a testbed version of the spacecraft on the ground.
This makes it less likely that the problem was caused by a
hardware failure or cosmic-ray hit; mission managers suspect the
event may be easily preventable. They are still studying an
apparent problem with the spacecraft's star tracker that was the
cause of Deep Space 1 entering safe mode.
#####
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Дата: 16 ноября 1998 (1998-11-16)
От: Alexander Bondugin
Тема: This Week On Galileo - November 16-20, 1998
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THIS WEEK ON GALILEO
November 16-20, 1998
During these last few days before its next encounter, Galileo spends
most of its time returning data acquired and stored on the spacecraft's
onboard tape recorder during its previous encounter, back in September.
The data will be overwritten by new data during the next encounter,
which will begin later this week.
Playback is interrupted twice this week, first to allow the spacecraft
to perform a final correction to its flight path as it approaches the
heart of the Jupiter system, and then a second time to perform regular
maintenance on its tape recorder. In addition, playback of data shares
transmission time with real-time observations made by the dust detector
instrument, which is collecting data on Jupiter's dust environment.
A variety of science data is returned this week, and like the last few
weeks of playback, it is retrieved from a part of the tape that has
been read through once before in this orbit. These data are entirely
new, re-processed with different parameters, or will be used to fill
gaps in previously returned data. Observations by the spacecraft
camera and near-infrared mapping spectrometer comprise the bulk of the
playback time and contain data describing the surface features of
Europa at high, regional and global resolutions. The spacecraft camera
also returns a single observation of Jupiter's rings.
Stay tuned for the return of Today on Galileo on Saturday, November 21,
as Galileo starts the seventh encounter of the Galileo Europa Mission!
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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Дата: 16 ноября 1998 (1998-11-16)
От: Alexander Bondugin
Тема: Great Expectations: The 1998 Leonid Meteor Storm
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Great Expectations: The 1998 Leonid Meteor Storm
Marshall Space Flight Center Space Science News
November 10, 1998
http://science.msfc.nasa.gov/newhome/headlines/ast10nov98_1.htm
Ready or not, here they come: the 1998 Leonid meteors. On the
morning of Nov. 17, bits and pieces of periodic comet
Tempel-Tuttle will hurtle into Earth's atmosphere at a
head-spinning 158,000 mph. There is little danger - few will
reach the ground. Most will distintegrate and, in the
process, produce a "shooting star". Experts think that this
year's Leonids could rival any meteor storm this century,
with peak rates greater than 40 shooting stars per second.
Or, it could be another run-of-the-mill meteor shower. We
won't know for sure until next week.
Comet Tempel-Tuttle spends most of its time far away in the
outer solar system, between the orbits of Saturn and Uranus.
Occasionally Tempel-Tuttle pays a visit to Earth when it
swings by the sun on its 33-yr elliptical orbit. The last
time this happened was just 10 months ago, in January 1998.
The comet passed within 0.36 AU of Earth and was easily seen
with binoculars and small telescopes.
When Tempel-Tuttle comes calling, it doesn't come alone. The
comet is surrounded by a cloud of ice and dust that bubbles
off the comet's nucleus as a result of solar heating. This
debris orbits the sun along with the comet, forming a thin
elongated stream of meteoroids. The Leonid meteor stream is
several hundred million km long, but only 35,000 km wide.
Earth is scheduled to pass through the meteor stream on Nov.
17. It's a narrow target, but if we hit it just right a
historic meteor storm could result. The last time this
happened was in 1966 when as many as 100,000 shooting stars
per hour were observed at some locations. Leonids in 1966
Since 1995, when Tempel-Tuttle began its return to the inner
solar system, the November Leonids have been better than
average. In 1995 observers saw about 40 shooting stars per
hour. In 1996 and 1997, 80 per hour were seen, and in 1997
the shower lasted for over 12 hours.
Eighty shooting stars per hour is enough to excite most
experienced meteor observers, but it's nothing compared to
the potential 1998 Leonids. If the shower is anything like
the 1966 outburst, it may be possible to see hundreds of
thousands per hour. The highest rates will occur only for the
brief interval while Earth is passing through the densest
part of the Leonid meteor stream. The ribbon of comet debris
is so narrow that Earth passes through the densest part in
less than two hours.
Experts agree that the best viewing sites for the Leonids are
likely to be found in Japan, China, and other parts of east
Asia.
But what do they know?
Even though the experts are predicting the storm will occur
over east Asia, it's still worth looking if you're located
elsewhere. The experts have been wrong before, notably in
1966. In that year the Leonids were expected to occur over
Europe, but observers in North America were treated to a
spectacular shower thousands of miles away. This recollection
by James Young at JPL's Table Mountain Observatory in
California gives a sense of what the storm was like:
"This very noteworthy [1966] meteor shower was nearly missed
altogether.... There were 2-5 meteors seen every second as we
scrambled to set up the only two cameras we had, as no real
preparations had been made for any observations or
photography. The shower was expected to occur over the
European continent.
"The shower peaked around 4 a.m., with some 50 meteors
falling per second. We all felt like we needed to put on
'hard hats'! The sky was absolutely full of meteors...a sight
never imagined...and never seen since! To further understand
the sheer intensity of this event, we blinked our eyes open
for the same time we normally blink them closed, and saw the
entire sky full of streaks...everywhere!"
NASA wants you!
For this year's Leonid meteor storm Science@NASA will be
collecting observations from amateur observers, including
meteor counts, pictures, and video. We plan to use your
observations as the subject of a Science News Headline on
Nov. 18 or 19. If you would like to participate simply follow
the simple instructions (http://www.spaceweather.com/leonids.html)
about how to observe and keep
records. Then, after the shower, submit your data.
How to view the Leonids
The Leonids are best viewed during the early morning hours
between about 2 a.m. and dawn. That's when the local sky is
pointing directly into the Leonid meteor stream. Like the
parent comet, Tempel-Tuttle, the Leonid meteoroids orbit the
sun in a direction opposite to that of Earth. As a result, we
collide with the Leonids head on at high speed, nearly
158,000 mph. These high velocities are the reason that the
Leonids usually produce more fireballs than other showers.
The constellation Leo rises about 12:30 a.m. local time. The
radiant of the Leonid shower is located inside the
sickle-shaped "question mark" asterism, highlighted in the
sky map below. To find the constellation, go outside and face
east-southeast. At 3 a.m. the question-mark pattern of stars
will appear approximately 40 degrees above the horizon. The
planet Mars, posing as a bright red star, is nearby.
You won't need binoculars or a telescope, the naked eye is
usually best for seeing meteors which often streak more than
45 degrees across the sky. The field of view of most
binoculars and telescopes is simply too narrow for good
meteor observations.
Experienced meteor observers suggest the following viewing
strategy: Dress warmly as the autumn nights are likely to be
cold. Bring a reclining chair, or spread a thick blanket over
a flat spot of ground. Lie down and look up somewhat toward
the south. Meteors can appear in any part of the sky,
although their trails will tend to point back toward the
radiant.
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