PLEASE NOTE:
*
CCNet DIGEST, 1 July 1999
--------------------------
(1) NEODyS AND 1999 AN10
Steve Chesley <chesley@dm.unipi.it>
(2) THE PROBLEM WITH IMPACT PREDICTIONS BASED ON A SINGLE
OBSERVATION
Brian Marsden <marsden@cfa0.harvard.edu>
(3) NASA CANCELS COMET LANDER MISSION
Linda Wong <tps@planetary.org>
(4) CONGRATULATIONS! BBC'S DAVID WHITEHOUSE WINS SCIENCE WRITERS
AWARD
BBC Online Network, 30 June 1999
(5) BETH CLARK TO HEAD MUSES-C ASTEROID SAMPLE RETURN MISSION
Andrew Yee <ayee@nova.astro.utoronto.ca>
(6) UNISPACE III
ESA News/Document Server <esanews@esrin.esa.it>
(7) THE (CANCELLED) CHAMPOLLION COMETARY MOLECULAR ANALYSIS
EXPERIMENT
P.R. Mahaffy et al., NASA,GODDARD SPACE FLIGHT
CTR
(8) UPS AND DOWNS IN PLANETARY SCIENCE
C.S. Shoemaker, US GEOLOGICAL SURVEY,FLAGSTAFF
(9) LARGE METEOROIDS IN THE LYRID STREAM
M. Beech & S. Nikolova, UNIVERSITY OF
REGINA
(10) THE INTERNAL STRUCTURES & DENSITY OF ASTEROIDS
L. Wilson et al., UNIVERSITY OF HAWAII
MANOA
(11) ROADMAP TO A STAR
J.L. Anderson, NASA, OFF SPACE SCI
(12) A BADLY TRANSLATED PROPOSAL: SPACE STATION AS ASTEROID
PATROL
R.K. Tchuyan et al., MOSCOW STATE TECH
UNIVERSITY
==================
(1) NEODyS AND 1999 AN10
From Steve Chesley <chesley@dm.unipi.it>
[as posted on the Minor Planet Mailing List, 29 June]
By the way, I saw a large spike in NEODyS queries yesterday, I
presume
because of the new Klet observation (just one?) of 1999 AN10.
Unfortunately NEODyS was in a bit of a lurch yesterday, but all
is well
now. Sorry 'bout that.
I have updated the risk page for 1999 AN10
<http://newton.dm.unipi.it/neodys/risk.html>.
The 2044 and 2046
collision risks increased by a factor of about 1.6 since a few
weeks
ago, and, unhappily, the nominal orbit actually moved closer to
the 2044
collision, making its likelihood something like 1 in 100,000 with
gaussian probabilities, or about half that with our simple
uniform
distribution. A passage with in the lunar distance in 2027 is now
very
likely (>90%).
-Steve
==================
(2) THE PROBLEM WITH IMPACT PREDICTIONS BASED ON A SINGLE
OBSERVATION
From Brian Marsden <marsden@cfa0.harvard.edu>
I am rather surprised that Steve Chesley should make his "1
in 100,000"
remark about the 2044 impact probability for 1999 AN10 on the
basis of
a SINGLE observation made more than three weeks after the
previous
observations. The observers at Klet are normally very reliable,
but the
fact that they reported only a single position and that they
indicated
that the image was "faint" is surely an invitation not
to take this
observation too seriously. I, too, had noticed that the nominal
orbit
utilizing this position decreased the 2027 miss distance (to
0.00065 AU
on Aug. 7.38 UT), with the subsequent revolution period of 1.69
years
interestingly close to the 1.70 years needed for a 2044 impact
(although the actual value for impact requires that we consider
many
more significant figures than noted here). In fairness to Steve,
it
should also be stressed that he says that the 1-in-100,000 impact
figure was based on gaussian probabilities, and as has often been
remarked, these are inapplicable in cases like this.
But there are now some additional observations, made under better
conditions, by Brett Gladman and Phil Nicholson with the 5-m
telescope
at Palomar on June 9, and these conflict some with the Klet June
20
position. The nominal solution using them (each of the six with
unit
weight), yet ignoring the June 20 observation, again increases
the
nominal 2027 miss distance (to 0.0019 AU on Aug. 7.33 UT). A miss
distance this large results in less of a change in the post-2027
revolution period from the current value of 1.76 years. This
nominal
solution changes the period only to 1.74 years, closer to the
1.73
years needed for a 2046 approach or the 1.75 years for a 2034
approach,
although neither of these particular solutions would yield a hit.
Certainly, both the 158-day and the 147-day arcs indicate a very
good
chance that 1999 AN10 will pass within the moon's distance in
2027 (now
better than the 88-day arc indicated for cislunar passage of 1997
XF11
in 2028). But there is still little to favor one post-2027
scenario
over another, and chances are enormously against any impact
before 2050
(and not all that much less against impact before 2100). Further
observations over the next several months are very much to be
encouraged!
Brian Marsden
======================
(3) NASA CANCELS COMET LANDER MISSION
From Linda Wong <tps@planetary.org>
Press Advisory: NASA Cancels Comet Lander Mission
NASA is today sending a letter to Congress announcing that they
are
canceling the Champollion comet lander mission being developed
for a
2003 launch. The Planetary Society urges Congress to reverse the
decision and calls for open hearings on the merits of the
cancellation.
A copy of a letter from the Society to the key Congressional
Committees
overseeing the NASA program is attached. For further information
see
our web site <http://planetary.org/>
http://planetary.org. Or you
may
call Society Executive Director, Louis Friedman at (626)793-5100
or
President, Bruce Murray at (626)395-3780.
Linda Wong
The Planetary Society
65 N. Catalina Ave.
Pasadena, CA 91106
Tel: (626) 793-5100
Fax: (626) 793-5528
E-mail: tps@planetary.org
Web: http://planetary.org
<http://planetary.org/>
-------------------------
LOUIS FRIEDMAN'S LETTER TO THE US CONGRESS
June 30, 1999
The Honorable James Sensenbrenner
Chairman, Science Committee
B-374
Washington, D.C. 20515
The Honorable George Brown
Ranking Member, Science Committee
B-374
Washington, D.C. 20515
Dear Reps. Sensenbrenner and Brown:
NASA just announced it is canceling the Champollion (Space
Technology
4) mission, one of the most exciting and important missions
conceived
to study comets, among the least known of bodies in our solar
system.
ST-4 is part of NASA's New Millennium program, started by NASA
Administrator Daniel Goldin to develop "cheaper, faster,
better"
technologies for space exploration. Shutting down the program is
unjustified both on scientific and technological grounds and
represents
a giant step backward for America's space program.
We urge your immediate intervention to reverse the decision to
terminate the mission. There is no reason to cancel Champollion,
scheduled for launch in 2003. The mission is being developed
within
budget and on schedule.
The payload for Champollion, selected through an open,
competitive,
peer-reviewed process, and ST-4 was recommended by the official
New
Millennium Advisory Group. The National Academy of Sciences
Committee
on Planetary and Lunar Exploration (COMPLEX) has repeatedly
emphasized
the importance of cometary missions for three decades.
Champollion is led by Brian Muirhead, a highly acclaimed manager
from
the Mars Pathfinder mission, which was praised throughout the
world as
an extraordinary blend of science, technology and robotic
adventure.
There's every reason to believe Champollion would be the equal of
Pathfinder - if Congress can prevent its silent execution.
NASA says one of the reasons it must shut down Champollion is to
pay
for unanticipated problems with the Chandra Advanced X-ray
Astrophysical Observatory (AXAF) and emergency repairs on the
Hubble
Space Telescope. This is the first time in more than a decade
that NASA
is penalizing a successful science and technology mission to pay
for
other programs that are experiencing cost overruns - a misguided
decision that sets a disturbing precedent. This is a stunning
reversal
of Mr. Goldin's policy.
NASA also says it needs to cancel Champollion to pay for extra
"reserves" in the Mars Sample Return mission, but the
sample return
development has just begun and there are many better ways to deal
with
the future reserves problem.
The United States has landed spacecraft on the moon, on other
planets,
and with the Champollion mission we will, for the first time
ever, land
on a comet and collect critical scientific data about these
primordial
bodies in our solar system. Champollion paves the way for
advanced
technology used on the Mars Sample Return mission, on the Europa
orbiter and other outer planet missions, and on future small body
missions to comets and asteroids.
Comets are remnants from the formation of our solar system 4.5
billion
years ago. The small, icy orbs have changed little over time and
provide a unique record to learn how our solar system originated.
Because comets have impacted the terrestrial planets, including
Earth,
for all of our history, they are known to have had a profound
effect on
planetary evolution. Composed of organic material, they are also
important to the studies of the origin of life and are a high
priority
for study by planetary scientists.
For three months Champollion would map the surface of the comet
Tempel
1, which is about 3.7 miles in diameter, then land/anchor onto
its
surface. Scientists know little about the surface of comets and
expect
to find hills on Tempel 1 that reach as high as 100 meters. Once
hooked
to the comet, the spacecraft will employ instruments to drill
into the
surface and retrieve samples for analysis.
Scientific instruments aboard the spacecraft to determine the
composition, physical properties and morphology of the comet
include a
near field camera, microscope, IR spectrometer, panoramic camera,
gas
chromatograph, and mass spectrometer. Among the advanced
technologies
the mission would validate are:
* Precision guidance systems to autonomously land and
attach to
the comet's surface;
* Multi-engine ion drive that builds on the highly
successful
Deep Space-1 mission;
* High-performance, inflatable solar arrays which
could
revolutionize future space power systems;
* First-of-a-kind surface and subsurface sampling
systems.
To reduce the cost and risk of future planetary missions, it's
essential to validate new and advanced technologies such as those
incorporated into the design of the Champollion spacecraft. For
example, the laser altimeter being developed for Champollion
provides
more precise information than current radar altimeters for the
steering
of a spacecraft to a safe landing. These are needed for the
automated
rendezvous and docking that is necessary for the Mars Sample
Return
mission.
The innovative hardware being developed to drill into the icy
comet
surface would later be incorporated on the Mars Surveyor '03 and
'05
missions to collect and take measurements of samples. Terminating
Champollion increases the risks in the Mars and outer planet
programs,
and sets back progress on future deep space and solar power
generation.
Champollion would be the first mission to utilize three ion
engines and
the first spacecraft with an inflatable solar array.
As noted above, there's no reason to terminate Champollion at
this
time. NASA's FY2000 budget has yet to be determined and there are
many
options that can be considered short of shutting down an
important and
well-performing project. AXAF and Hubble are current budget
issues, and
NASA should solve them with current funding. Additionally, money
saved
from Champollion will not be realized until after both of these
missions are launched. More than $16 million has already been
spent on
Champollion and only $38 million is budgeted in FY 2000, money
already
included in the Administration's budget request.
The Planetary Society urges your support for Champollion and your
efforts to save this highly valuable project. Are financial
problems
within the Office of Space Science really so great as to raise
the
prospect of terminating a strongly supported and authorized
program? If
so, Congress should hold hearings so that all the facts and
assumptions
involved can be scrutinized by the outside scientific and
technological
communities, as well as by
the public.
Sincerely,
Louis Friedman
Executive Director
===================
(4) CONGRATULATIONS! BBC'S DAVID WHITEHOUSE WINS SCIENCE WRITERS
AWARD
From the BBC Online Network, 30 June 1999
http://news.bbc.co.uk/hi/english/sci/tech/newsid_381000/381874.stm
BBC News Online's Science Editor has picked up one of the UK's
top
science writers' awards. Dr David Whitehouse has won a Glaxo
award for
a story he wrote about Europa, one of Jupiter's moons.
The article took the reader on an imaginary space mission to the
icy
world, which many scientists believe may harbour extraterrestrial
life.
Dr Whitehouse suggested a probe might land on Europa, drill
through the
moon's surface and release a hydrobot to search for life in
the oceans
that many people think exist beneath the ice. Aliens Beneath The
Ice
was published in The Independent newspaper.
The Glaxo Wellcome ABSW Science Writers' Awards were presented at
the
Tate Gallery, London, by Sir Richard Sykes, Chairman of Glaxo
Wellcome
plc.
FULL STORY at
http://news.bbc.co.uk/hi/english/sci/tech/newsid_381000/381874.stm
====================
(5) BETH CLARK TO HEAD MUSES-C ASTEROID SAMPLE RETURN MISSION
From Andrew Yee <ayee@nova.astro.utoronto.ca>
Cornell researcher Beth Clark named by NASA to head research team
for
2002 asteroid sample return mission (Forwarded)
News Service
Cornell University
Contact: David Brand
Office: (607) 255-3651
E-Mail: deb27@cornell.edu
FOR RELEASE: June 30, 1999
Cornell researcher Beth Clark named by NASA to head research team
for
2002 asteroid sample return mission
ITHACA, N.Y. -- Beth E. Clark, a research associate in Cornell
University's Department of Astronomy for the past three years,
has
been named by NASA to lead a research team for history's first
asteroid sample return mission.
The 2002 joint mission with Japan will send a space vehicle to
land
on an asteroid, collect a sample of the surface and return it to
Earth for analysis. This will be the first time that a space
vehicle
has attempted a landing on an asteroid.
Clark will lead the team that will develop the near infrared
spectrometer to be carried aboard a miniature robotic rover
vehicle
that will be deployed by the spacecraft to explore a small area
of
the asteroid's surface. The spacecraft will shoot pellets into
the
surface to collect a few grams of surface samples, which it will
transfer to the Earth return module.
In congratulating Clark on her appointment, Joseph Veverka,
professor
of astronomy and incoming chair of the Cornell Department of
Astronomy, said the awarding of the contract follows "in the
great
tradition of Cornell's involvement with landers," beginning
with the
Apollo program, through the Viking program and currently with the
Mars Pathfinder missions. Veverka was a member of the team that
originally proposed the collaborative asteroid mission in 1997.
The mission, named MUSES-C (for Mu Space Engineering Spacecraft)
will
be the third (thus the "C") in a series of missions
managed by the
Japanese Institute of Space and Astronautical Science (ISAS) and
NASA's Jet Propulsion Laboratory (JPL). The mission is scheduled
to
be launched from a Japanese M5 rocket in Kagoshima, Japan, in
January
2002.
The target for the space mission is the asteroid 4660 Nereus,
with
the asteroid 1989 ML as a backup. Both asteroids come to within
about
75 million miles of Earth. The space vehicle will arrive at the
asteroid in April 2003, alight on the surface up to three times
and
collect surface samples for return to Earth in January 2006.
The asteroid mission will test a number of new technologies,
including solar electric propulsion, autonomous landing and
sampling
and the hyperbolic re-entry of the sample return capsule to
Earth.
The NASA MUSES-C group will develop the rover and support
services
for the mission. The rover, a tiny vehicle weighing about one
kilogram (2.2 pounds), will be the smallest rover ever to fly on
a
space mission. It will carry several instruments to observe both
in
the visual and near-infrared wavelengths.
Clark says her team's job is to work with engineers at JPL to
specify
the science requirements in the development of a near-infrared
spectrometer roughly the size of a hand-held calculator. It will
take
advantage of nanotechnology to build the smallest such instrument
ever flown.
Clark, a researcher in the Cornell astronomy department's Center
for
Radiophysics and Space Research, obtained her B.S. in 1986 at the
University of California at Berkeley and her Ph.D. in 1993 from
the
University of Hawaii. From 1993 to 1995, she was a Harlan J.
Smith
postdoctoral fellow at McDonald Observatory, the University of
Texas.
From 1995 to 1996, she was a National Science Foundation visiting
professor at the Lunar and Planetary Laboratory, University of
Arizona. She joined Cornell's astronomy department as a research
associate in 1996.
For the past three years, Clark has been a convener and member of
the
scientific organizing committee of the seventh International
Conference on Asteroids, Comets and Meteors, to be held at
Cornell
July 26-30.
She also has served on scientific review panels for the Hubble
Space
Telescope, the National Science Foundation and for NASA.
Related World Wide Web sites:
The following sites provide additional information on this news
release. Some might not be part of the Cornell University
community,
and Cornell has no control over their content or availability.
* MUSES-C home page: http://www.muses-c.isas.ac.jp/
IMAGE CAPTION:
[http://www.news.cornell.edu/releases/June99/clark.nasa.deb.html]
Beth E. Clark, a research associate in Cornell University's
Department of Astronomy (holding a model of the asteroid Phobos)
has
been named by NASA to head a research team for a 2002 sample
return
mission to the asteroid 4660 Nereus. Photo by Charles
Harrington/Cornell University Photography.
===============
(6) UNISPACE III
From ESA News/Document Server <esanews@esrin.esa.it>
Nr. 27-99 - Paris, 25 June 1999
-----------------------------------------------------------------------------
UNISPACE III, an international conference on the peaceful uses of
outer
-----------------------------------------------------------------------------
The third United Nations conference on the exploration and
peaceful
uses of outer space (UNISPACE III) will be held in Vienna
(Austria)
from 19 to 30 July 1999. High-level government officials and
policy-makers from the 185 Member States of the UN, heads of
space
agencies and representatives of intergovernmental and
non-governmental
organizations will gather at this international forum to exchange
ideas
on the direction of space activities, establish professional
networks
and explore commercial opportunities. Top executives from
space-related
firms will also attend the event.
UNISPACE III aims to foster a greater understanding and better
use of
space science and technology to assist and stimulate economic and
social growth, particularly in developing countries. It is of
great
importance for the European Space Agency. ESA has, for many
years, been
a firm advocate for the United Nations Office for Outer Space
Affairs,
and on behalf of its Member States, is the largest contributor to
the
UN Space Applications programme.
ESA, together with its Member States, has played a key role in
coordinating and securing significant European participation in
this
event of worldwide relevance. UNISPACE III, an intergovernmental
conference, will also feature over 40 workshops and several
symposia,
seminars and round tables. The opening ceremony is scheduled for
Monday
19 July at the Austria Centre in Vienna (Hall A, 10:00-12:00
hrs). The
Director General of ESA, Mr Antonio Rodota`, will address the
audience
at the plenary session on Tuesday 20 July (Hall A, 10:00-13:00
hrs).
ESA has also coordinated the organization of three workshops on
Satellite Navigation, Disaster Management (in cooperation with
the
Japanese space agency - NASDA) and Intellectual Property and
Space
Activities.
An exhibition featuring global achievements in the field of space
technology, current and future development tools, emerging
technologies, and ongoing collaborative projects, will be held
during
the first week of the conference. The ESA stand will host a
series of
demonstrations, linked to the themes of the conference, with the
main
emphasis on satellite communication systems and Earth observation
data
exchange and their applications. The exhibition will start on
Sunday 18
July at 11:00. It will be open to the public until Friday 23 July
12:00
hrs, except on Monday 19 and Tuesday 20 July, which will be
reserved
for registered conference participants.
On Tuesday 20 July, ESA astronauts will be available at the
conference
for interviews with the media.
More information on the conference and programme can be found on
the
Internet at http://www.un.or.at/OOSA/
Media representatives wishing to attend the conference are kindly
requested to follow the instructions given in the forms attached
or to
contact directly : The Media Accreditation Assistant, United
Nations
Information Service, Vienna G0537 PO BOX 500, A-1400 Vienna,
Austria -
Fax. + 43 1 21 346-3342
If you received this press release via e-mail or from the Web,
without
attached forms, please obtain an accreditation request form from
http://www.un.or.at/OOSA/unisp-3/accrinfo.html
===============
(7) THE (CANCELLED) CHAMPOLLION COMETARY MOLECULAR ANALYSIS
EXPERIMENT
P..R. Mahaffy*) et al.: The Champollion cometary molecular
analysis
experiment. ADVANCES IN SPACE RESEARCH, 1999, Vol.23, No.2,
pp.349-359
*) NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD,20771
The Chemical Analysis of Released Gas Experiment (CHARGE), is one
of
several investigations selected for the Champollion New
Millennium DS4
Mission. CHARGE is presently being designed to carry out a
detailed
molecular and isotopic analysis of material collected from the
surface
and several centimeters below the surface of comet Tempel I. The
highest priority scientific issues addressed by this
investigation
include: the chemical conditions present in the region of
cometary
formation; the chemical changes during cometary formation and
over the
lifetime of the comet; the relationship of comets to other
primitive
and more evolved bodies in the solar system and to the parent
interstellar cloud; the contribution of cometary material to the
atmospheres and oceans of planets; and the nature of the mixture
of
ices and dust grains which give rise to the coma and extended
sources
of gas as a comet approaches perihelion. CHARGE will be designed
to
thermally process samples of solid phase material from near the
ambient
temperature to approximately 900 K. Gases evolved from the frozen
ices
will be continuously analyzed as a function of sample temperature
by a
quadrupole mass spectrometer with a mass range of 2 to 300 amu. A
broad
range of major and trace species, both organic and inorganic,
from the
gases evolved from the solid samples will undergo both chemical
and
cold trapping for subsequent analysis by gas chromatograph mass
spectrometer (GCMS) analysis. CHARGE technology heritage includes
the
Galileo Probe Mass Spectrometer (Niemann et al., 1996) that
successfully measured the composition of Jupiter's atmosphere in
December of 1995. The landed portion of the mission will enable
analysis of subsurface materials and allow identification of
organic
species present at sub-parts per million mole-fraction in the
nucleus.
Prior to the landed operations, CHARGE will carry out
measurements from
orbit for a period of several weeks. (C) 1999 COSPAR. Published
by
Elsevier Science Ltd.
====================
(8) UPS AND DOWNS IN PLANETARY SCIENCE
C.S. Shoemaker: Ups and downs in planetary science. ANNUAL REVIEW
OF
EARTH AND PLANETARY SCIENCES, 1999, Vol.27, p.1 (18 pages)
US GEOLOGICAL SURVEY,FLAGSTAFF,AZ,86001
The field of planetary science as it developed during the
lifetimes of
Gene and Carolyn Shoemaker has sustained a period of exciting
growth.
Surveying the skies for planet-crossing asteroids and comets and
studying the results of their impact upon the planets, especially
the
Earth, was for Gene and Carolyn an intense and satisfying quest
for
knowledge. It all started when Gene envisioned man going to the
Moon,
especially himself. After that, one thing led to another: the
study of
nuclear craters and a comparison with Meteor Crater, Arizona; the
Apollo project and a succession of unmanned space missions to the
inner
and outer planets; an awareness of cratering throughout our solar
system; the search for near-Earth asteroids and comets; a study
of
ancient craters in Australia; and the impact of Shoemaker-Levy 9
on
Jupiter. The new paradigm of impact cratering as a cause for mass
extinction and the opening of space for the development of new
life
forms have been causes to champion. Copyright 1999, Institute for
Scientific Information Inc.
==============
(9) LARGE METEOROIDS IN THE LYRID STREAM
M. Beech*) & S. Nikolova: Large meteoroids in the Lyrid
stream. MONTHLY
NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1999, Vol.305, No.2,
pp.253-258
*) UNIVERSITY OF REGINA,CAMPION COLL,REGINA,SK S4S 0A2,CANADA
The outburst of the Lyrid meteor shower in 1803 was remarkable
for
being rich in bright fireballs and the generation of
electrophonic
sounds. The implications implicit to the detection of
electrophonic
sounds are studied in this paper. We present estimates for the
minimum-sized Lyrid meteoroid capable of generating electrophonic
sounds, and compare these lower limits with the largest meteoroid
that
might reasonably be ejected from a cometary nucleus through
coupling
with the sublimation gas outflow. A difference of a factor of
order 30
is found between the two limiting sizes. A minimum diameter of
order Im
is required for a Lyrid meteoroid to satisfy the conditions
necessary
for generating electrophonic sounds. The mechanisms responsible
for the
placement of large, metre-sized meteoroids into the Lyrid stream
are
not well defined, but they possibly relate to surface ageing
effects of
the parent comet, Comet C/1861 G1 Thatcher, and to a history of
nuclear
fragmentation.
==================
(10) THE INTERNAL STRUCTURES & DENSITY OF ASTEROIDS
L. Wilson*), L. Keil, S.J. Love: The internal structures and
densities
of asteroids. METEORITICS & PLANETARY SCIENCE, 1999, Vol.34,
No.3,
pp.479-483
*) UNIVERSITY OF HAWAII MANOA,HAWAII INST GEOPHYS & PLANETOL,
HONOLULU,
HI, 96822
Four asteroidal bodies (the Martian satellites Phobos and Deimos
and
the main-belt asteroids 243 Ida and 253 Mathilde) have now been
the
subjects of sufficiently close encounters by spacecraft that the
masses
and sizes and, hence, the densities of these bodies can be
estimated to
similar to 10%. All of these asteroids are significantly less
dense
than most members of the classes of meteorites identified as
being
compositionally most nearly similar to them on the basis of
spectral
characteristics. We show that two processes can act,
independently or
in concert, during the evolutionary histories of asteroids to
produce a
low bulk density. One of these processes is the result of one or
more
impact events and can affect any asteroid type, whereas the other
can
occur only for certain types of small asteroids that have
undergone
aqueous alteration. Copyright property of the Meteoritical
Society,
1999.
==============
(11) ROADMAP TO A STAR
J.L. Anderson: Roadmap to a star. ACTA ASTRONAUTICA, 1999,
Vol.44,
No.2-4, pp.91-97
NASA, OFF SPACE SCI, WASHINGTON,DC,20546
NASA is currently constructing an Interstellar Roadmap that will
outline a progressive series of phased technology efforts over
several
decades that would enable new science beyond the solar
system,leading
to and culminating in robotics exploration of nearby stars. The
Roadmap
is structured around a decadal progression of science missions
and
enabling technologies in which each decadal cycle has an
intrinsic
value in itself. The Roadmap serves at least 5 functions: 1) it
lays
the foundation for the development of a broad new strategic
thrust of
space exploration and development; 2) it outlines a long term
progressive program for which each phase has an intrinsic value
and can
be argued independently of a Star Mission itself; 3) it defines a
phased approach that would culminate in a large scale
breakthrough
beamed energy capability that would have broad planetary and
terrestrial applicability; 4) it describes an endeavor that could
provide the technological basis of a U.S. economic engine for the
first
half of the 21st century; and 5) it provides a focus and a
structure
around which new government/industry economic relationships may
be
established. This paper outlines the process for constructing the
Roadmap which is due to be completed in Fall 1998. It also poses
questions raised by a mission of such scale and suggests some of
the
strategic value of such a Roadmap. (C) 1999 Published by Elsevier
Science Ltd. All rights reserved.
================
(12) A BADLY TRANSLATED PROPOSAL: SPACE STATION AS ASTEROID
PATROL
R.K. Tchuyan*), V.V. Bagdasaryan, A.P. Belousov, L.A. Latusev: On
the
strategy of space station injection in the point of earth-moon
libration - Way of making the asteroid patrol. ACTA ASTRONAUTICA,
1999,
Vol.44, No.2-4, pp.109-112
*) MOSCOW STATE TECH UNIVERSITY,MOSCOW STATE AVIAT
INST,MOSCOW,RUSSIA
One of the most important problem in the ecological area that
stay for
humanity is the problem of prevention Earth and asteroids
collision.
The danger of such collision isn't realized of the general
public. But
we know that on average twice in every century the Earth comes
into
collision with the large celestial bodies (for example Tungussky
or
Arizonsky meteorites). The incidence of such meteorite in density
population region of the Earth will simulate the ecumenical
catastrophe. Much more seldom the Earth experiences collision
with the particularly large celestial bodies. In accordance with
one of
the hypotheses namely the collision Earth with such body
65,000,000
years ago leads to the global change of Earth biosphere ( in
particular
to the extinction of dinosaurs). Now we are able to stave off or
at
least to forewarn of this danger. One of the way for that is
making the
specific space station asteroid patrol. Such the station will be
able
to track the approaching celestial bodies and perhaps (on second
stage)
to attempt altering its trajectory (for example with directional
thermonuclear explosions) Some of the expedient points in the
Space for
the asteroid patrol's placing are the librations' points of the
Earth -
Moon system. In the report the preliminary results of analysis
the
problem of space station's taking into the libration's point are
presented. For this taking it is suggested the electric jet
propulsion
to use. (C) 1999 Published by Elsevier Science Ltd. All rights
reserved.
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