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发信人: bage (网事如疯·春心萌动), 信区: AerospaceScience
标 题: SpaceViews -- 2000 July 31(转载)
发信站: 哈工大紫丁香 (2000年12月23日17:49:20 星期六), 转信
【 以下文字转载自 bage 的信箱 】
【 原文由 hitsma@0451.com 所发表 】
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S P A C E V I E W S
Issue 2000.31
2000 July 31
http://www.spaceviews.com/2000/0731/
*** News ***
Zvezda Docks with International Space Station
NASA Selects Rover for 2003 Mars Mission
Pluto Mission May Be in Jeopardy
Sea Launch Places Communications Satellite in Orbit
Astronomers Witness the Demise of Comet LINEAR
Parliament Report Recommends Bigger, Bolder British Space
Program
X-34 Program Resumes Tests
NEAR Starts Moving Away from Eros
DS1 Repairs to Allow Comet Flyby
Titan 4 Changes Boost Lockheed Martin Profits
SpaceViews Event Horizon
Other News
*** Reviews ***
Space Cowboys: Armageddon for the Geritol Set?
*** News ***
Zvezda Docks with International Space Station
The Russian-built Zvezda service module successfully docked
with the International Space Station Tuesday evening, completing a key
step in the assembly of the orbiting facility.
Zvezda made contact with the Zarya module of the ISS at 8:45
pm EDT Tuesday evening (0045 UT Wednesday). No major problems were
reported with the automated docking, which took place while the
spacecraft passed over Kazakhstan, in range of Russian ground
stations.
"We have contact confirmed, capture is confirmed," said NASA
spokesperson Kyle Herring, covering the docking from the Russian
mission control center in Korolev, outside of Moscow. "We have a
successful capture of the Zvezda as it becomes a permanent member of
the International Space Station."
During the docking Zvezda served as the passive target, as the
ISS -- composed of the Zarya and Unity modules -- maneuvered towards
Zvezda. During the final approach the ISS approached Zvezda at the
rate of just 0.2 meters per second (0.45 mph) during the final
approach to the module.
Minutes after docking hooks and latches on both modules locked
into place to keep Zarya and Zvezda securely attached to one another.
Zvezda's solar panels, which had been locked into an edge-on position
during the docking to prevent any damage from Zarya's thrusters, were
unlocked and allowed to track the Sun again to maintain power to the
module. The passageway between the two modules was also scheduled to
be pressurized.
After several days of work checking out the systems on Zvezda,
controllers will begin transferring attitude control and other systems
from Zarya to Zvezda on Sunday. Those computers on Zvezda, supplied
by the European Space Agency, will be used to control the station
until other computer systems are installed on later assembly flights.
The docking is a key milestone for the station, as the
addition of the Zvezda module allows the station to be inhabited for
months at a time by three-person crews. The first such crew,
Expedition One, is scheduled for launch on a Soyuz from Baikonur,
Kazakhstan in late October. The crew includes American astronaut
William Shepard, the mission commander, and Russian cosmonauts Yuri
Gidzenko and Sergei Krikalev. They will remain on ISS until February
of next year, when they are relieved by the next crew.
The next step in the ISS assembly process will be the launch
of a Progress cargo spacecraft to the station. The spacecraft,
scheduled to be launched on a Soyuz from Baikonur on August 6, will
dock with the station two days later and provide supplies for the crew
as well as propellant to reboost the station's orbit.
That will be followed by shuttle mission STS-106, scheduled
for launch September 8. The crew of that mission will work to outfit
Zvezda and the rest of the station for its first long-duration crew. A
month later STS-92 will install a truss structure that will serve as
the early framework for what will eventually become a large array of
solar panels.
About a month after the Expedition One crew arrives, shuttle
mission STS-97 will install a Photovoltaic Module on the truss
structure with the first set of solar panels. That will be followed in
early 2001 with the launch of the Destiny lab module on mission STS-
98.
NASA Selects Rover for 2003 Mars Mission
NASA will send one and possibly two landers, each carrying
large rovers that will serve as "robotic field geologists", to Mars in
2003, the space agency unexpectedly announced Thursday.
"Today I am announcing that we have selected the Mars
Exploration Program Rover rather than the orbiter option, which was an
extremely difficult decision to make," Ed Weiler, NASA associate
administrator for space science, said in a statement released late
Thursday afternoon.
Under the plan, a Delta 2 will lift off on June 4, 2003,
sending the as-yet unnamed spacecraft on a seven and a half month trip
to Mars. The spacecraft will land on Mars on January 20, 2004, using
airbags to cushion the landing in much the same way Mars Pathfinder
did when it landed in July 1997. After landing the airbags will
deflate and the lander's panels, or "petals", will unfold, revealing
the lander.
Unlike Mars Pathfinder, whose Sojourner rover was included
almost as an afterthought, the 150-kilogram (330-pound) rover will be
the primary payload of the lander. The rover will be able to travel
as far as 100 meters (330 feet) per day, carrying a payload of
instruments that, in the words of one scientist, makes it a "robotic
field geologist."
The rover's scientific payload includes panoramic and
microscopic cameras, a thermal infrared spectrometer, a Mossbauer
spectrometer to identify iron-bearing minerals, and an alpha proton x-
ray spectrometer to measure the elemental composition of rocks and
soil. The rover will also include a rock abrasion tool (RAT), which
the rover will use to expose fresh surfaces on rocks for study by its
instruments.
"It has everything a human field geologist has, and then much
more," said Stephen Squyres of Cornell University, principal
investigator for the rover's scientific payload. "It has 20/20
vision, the ability to get inside rocks using the rock abrasion tool,
it has spectrometers to tell us what rocks are made of, and it has a
microscopic imager to tell us what things look like at a fine scale."
"It can use all these tools together to read the geologic
record at the landing site and to tell us what conditions were once
like, how much water was there, and, in particular, how habitable the
site was -- how suitable it would have been as an abode for life,"
Squyres added.
"Furthermore, the rover offers never-before-possible
opportunities for discoveries about the Martian surface at scales
ranging from microscopic to that of gigantic boulders," said Jim
Garvin, NASA Mars program scientist. "This is a key stepping stone to
the future of our Mars exploration program."
The landing site for the rover has yet to be selected, but the
space agency said in a statement that the rover would likely set down
in a former lakebed or channel: a place where water might once have
flowed on the Red Planet. The rover's mission on the surface would
late at least 90 days.
The cost of the mission was not announced by NASA, but
published reports elsewhere have pegged the cost of the mission at
$300-400 million, somewhat more than the $250-million Mars Pathfinder
mission and much more than failed Mars Polar Lander mission last year,
which cost about half as much as Pathfinder.
"This project can be accommodated within the President's
budget request for NASA and we will spend the next few weeks refining
our budget estimates and other requirements, plus the impacts and the
consequences of sending two rovers to Mars instead of one," said Scott
Hubbard, Mars program director at NASA headquarters.
NASA is leaving the door open for sending a second identical
lander and rover to Mars at the same time, an option that could
increase the mission's price by up to $200 million. "We are
evaluating the implications of a two-rover option," said Weiler. "I
intend to make a decision in the next few weeks so that, if the
decision is to proceed with two rovers, we can meet the development
schedule for a 2003 launch."
The timing of the announcement took some by surprise. NASA
had announced earlier in the month that it would reveal its choice for
the 2003 mission during a press conference Monday, July 24. However,
just a day after announcing the press conference, the space agency
canceled it, saying it would need up to one or two additional weeks to
make a decision.
Thursday's announcement about the rover decision came without
any advance notice. It also lacked any explanation of the apparently
convoluted and agonizing decision-making process within the agency.
The rover beat out a competing proposal from Lockheed Martin
to send an advanced scientific orbiter to the planet during the 2003
launch window. That spacecraft would have included a high-resolution
camera capable of resolving objects just 60 centimeters (two feet)
across on the surface, as well as other instruments suited to
searching for evidence of past or present water.
The rover mission will follow NASA's next Mars mission, the
2001 Mars Surveyor orbiter. The spacecraft will carry a thermal
emission mapper and gamma-ray spectrometer to study the elemental and
mineral composition of the Martian surface as well as an experiment to
characterize the radiation environment in the vicinity of Mars.
The rover will also arrive at around the same time as Europe's
first Mars mission, Mars Express. That mission includes both an
orbiter as well as the British-built Beagle 2 lander, which will also
use airbags to cushion its landing on the planet. While lacking a
rover, Beagle 2 will carry a suite of instruments that will examine
rock and soil samples from its landing site to look for evidence of
water or organic materials.
Another mission, Japan's Nozomi spacecraft, will also arrive
at Mars in late 2003. That spacecraft will go into orbit and study
the planet's faint magnetic fields and its interaction with the solar
wind. Launched in 1998, Nozomi was to go into Mars orbit last year,
but a thruster problem forced controllers to wait until the end of
2003, when a more favorable opportunity will allow Nozomi to enter
orbit using less propellant.
Pluto Mission May Be in Jeopardy
A planned NASA mission to Pluto, the most distant planet in
the solar system and the only one yet to be explored by spacecraft,
may be in danger of cancellation, sources reported last week.
Reports and rumors circulating on the Internet in the last
week claimed that NASA is considering canceling the Pluto Kuiper
Express (PKE) mission, scheduled for launch in 2004, as a cost-cutting
move.
Those rumors grew louder on Thursday, after NASA announced it
would send one rover to Mars in 2003 and was considering sending a
second, identical one at the same time. Some space activists fear
that a second 2003 Mars rover could use money planned for PKE.
The reports, while not confirmed officially by NASA, were
enough to prompt the Planetary Society to alert its 100,000 members
worldwide, asking them to contact the space agency as well as members
of Congress to express their support for a Pluto mission.
"For four decades we have sent missions of exploration into
space, from heat-seared Mercury to the blue wonder of Neptune," said
Louis Friedman, executive director of the Planetary Society. "What
will it say of our generation -- and our lack of wonder and curiosity
-- if we stop now, right before exploring Pluto, the last outpost
planet of our solar system?"
NASA spokesman Don Savage told MSNBC that the agency was
considering changes to PKE, noting that "a number of missions" were
running over their budgets. He did not give any specific timeline for
a decision, or what options the agency was considering for PKE and
other space science missions.
The Planetary Society, however, believes there is enough
funding for PKE and other missions in NASA's budget for the next
several years. "Either administration support for space science is
now diminishing or NASA is returning to the old days of fewer, more
expensive missions," said Friedman.
A Pluto mission has strong support in the planetary science
community. A 1998 report by the Committee for Planetary Exploration
(COMPLEX) of the National Research Council recommended a spacecraft
mission to Pluto and its moon Charon, a recommendation endorsed by
another COMPLEX report issued earlier this year.
"The highest scientific priority for the exploration of the
trans-neptunian solar system is extensive and detailed measurement of
the fundamental physical and chemical properties of the Pluto-Charon
system," the report noted. "Because Pluto and Charon are barely
spatially resolvable from Earth, many of the relevant properties can
be measured only by a robotic spacecraft."
PKE is one of three missions of NASA's Outer Planets/Solar
Probe, or "Ice and Fire", project. PKE, along with Europa Orbiter and
Solar Probe, will share some technologies and subsystems, lowering the
development cost for each spacecraft.
In particular, Europa Orbiter and PKE are very similar, with
propulsion and scientific instruments the only major systems that are
different between the two spacecraft. Project officials at JPL
originally planned to build the two spacecraft simultaneously, then
set PKE aside for a year while completing work on Europa Orbiter,
which was baselined for a 2003 launch.
In recent months, though, NASA has reportedly been considering
delaying Europa Orbiter by several years, and possibly moving PKE up
to the Europa mission's 2003 launch window. PKE's current mission
design includes a swingby of Jupiter, which would not be available in
its current form after 2004.
PKE started life as Pluto Fast Flyby (PFF), a small spacecraft
originally designed in late 1991 and early 1992 to see how small of a
spacecraft could be built for a Pluto flyby mission and still return
significant scientific data. PFF was inspired by the 1991 release of
a set of U.S. Postal Service stamps which depicted all the planets in
the solar system along with a spacecraft that has visited them: Pluto,
not having been visited by any mission, was listed as "Not Yet
Explored".
Sea Launch Places Communications Satellite in Orbit
A Zenit 3SL rocket successfully launched an American
communications satellite for the multinational Sea Launch company
Friday, the first since a failed launch in March.
The Zenit lifted off on schedule at 6:42 pm EDT (2242 UT)
Friday, July 28, from Sea Launch's mobile, floating launch platform,
located on the Equator at 154 degrees west longitude in the Pacific
Ocean. Its payload, the PAS-9 satellite for PanAmSat, was placed into
a geosynchronous transfer orbit about one hour and 45 minutes after
launch.
"Today's success clearly establishes Sea Launch's position as
a proven launch services provider," said Sea Launch president Will
Trafton. "We how have three very successful missions and have moved
into full scale operations."
The launch is the first for Sea Launch since a March 12 launch
that failed to place its payload, the ICO F-1 satellite for
communications company ICO, into orbit.
That failure was traced to a software glitch that failed to
close a helium valve in a pneumatic system in the vehicle's second
stage. The open valve allowed helium to escape, lowering pressure in
the system until it could no longer operate the second-stage engine,
causing the booster to fail to reach orbital velocity and crash
instead in the eastern Pacific.
The 3,650-kg (8,030-lb.) PAS-9 satellite, a Hughes model HS
601 HP, will be positioned at 58 degrees west longitude, replacing the
existing PAS-5 satellite. The satellite will provide video services
for the Americas, including direct television broadcasts for Mexico.
The launch was the fourth for Sea Launch, after an inaugural
demonstration flight in March 1999 and first commercial flight in
October of that year, as well as March's failure. The next Sea Launch
mission is tentatively planned for mid-September, when a Zenit 3SL
will launch the Thuraya communications satellite for the United Arab
Emirates.
Sea Launch, headquartered in Long Beach, California, is a
joint effort by a number of companies, led by Boeing. Ukrainian
aerospace company SDO Yuzhnoye/PO Yuzhmash provides the Zenit booster,
RSC Energia the upper stage used by the Zenit, and the Anglo-Norwegian
Kvaerner Group the two vessels used by Sea Launch.
Astronomers Witness the Demise of Comet LINEAR
A comet passing through the inner solar system has suffered
outbursts so powerful that the icy nucleus of the comet has completely
blown apart, astronomers reported last week.
Astronomers at the Jacobus Kapteyn Telescope, a 1-meter (39-
inch) telescope on La Palma in the Canary Islands, saw what they
called the "complete disruption" of LINEAR's nucleus between July 24
and 27.
"The central condensation was highly condensed and showed the
typical 'teardrop' form in the evening of July 23rd and July 24th,
although its brightness decreased by a factor of about three between
the two nights," said Mark Kidger, an astronomer at the observatory.
The nucleus is hidden within the central condensation seen in images
of the comet.
"In the evening of July 25th something very odd was happening
to the comet: the central condensation was seen to be strongly
elongated, with a very flat brightness distribution," Kidger said.
"The condensation's brightness faded further and its length increased
on the following nights."
Kidger and others believe that instead of breaking up into a
number of distinct fragments, as comet Shoemaker-Levy 9 did after a
close approach to Jupiter in 1992, LINEAR has completely disrupted,
with no fragments large enough to be detected by telescopes on Earth.
"On July 27 there was no evidence of any local brightness
peaks that would indicate the presence of sub-nuclei," said Kidger.
Moreover, the central condensation is now expanding at a speed of 40
meters per second (90 mph), which would be true if the condensation
was made of solid particles created by the nucleus' breakup rather
than gas. The gas tail seen prior to the breakup, which disappeared
between July 23 and 24, has reformed as an extension of the
condensation.
LINEAR had shown evidence of outbursts prior to last week's
breakup. On July 5 the Hubble Space Telescope witnessed one such
outburst, as the comet's brightness increased by 50 percent in less
than four hours, fading back to normal two days later. Hubble was
also able to see a chunk of the nucleus, ejected by the outburst, in
the comet's tail.
While claiming that he and colleagues "lucked out completely,"
Hal Weaver of the Johns Hopkins University said that the serendipitous
Hubble observation of the outburst more likely means that such
outbursts were quite common for LINEAR.
The comet, discovered last September by the automated Lincoln
Near-Earth Asteroid Research (LINEAR) observatory in New Mexico and
officially designated C/1999 S4, is believed by astronomers to be
making its first pass ever through the inner solar system. Because
comet LINEAR never passed close to the Sun before now, it should have
a greater proportion of ices that would sublimate, or turn into gas,
than older comets.
Prior to the breakup, the large number of outbursts were
acting as thrusters, generating "non-gravitational" forces that
perturbed the comet's orbit. The effect of those forces on the
comet's orbit led some astronomers to conclude that comet LINEAR's
nucleus was not large to begin with.
"Basically, I think C/1999 S4 is simply a rather small comet,"
said Brian Marsden of the Minor Planet Center at the Harvard-
Smithsonian Center for Astrophysics. "So that's why the non-
gravitational terms in the equations describing LINEAR's orbit are so
large for this first-pass comet."
When comet LINEAR was discovered last year, it was more than
four times farther from the Sun than the Earth. Because it was
discovered so far from the Sun, astronomers thought it might brighten
enough to be seen by the naked eye as it reached perihelion, the
closest point in its orbit to the Sun, this month, but the comet
remained too dim to be seen without binoculars or a telescope.
The disrupted comet LINEAR may fade away from view entirely
within days, as the cloud that contains the material that formerly
made up the nucleus continues to disperse. However, the outbursts
that preceded the breakup did provide some measure of satisfaction to
astronomers.
"In one surge of brilliance this under-performing comet showed
us what it could have been," said Weaver.
Parliament Report Recommends Bigger, Bolder British Space Program
A recent report by a committee of the British Parliament
recommends that the nation increase the size and scope of its space
activities, although not necessarily in conjunction with the European
Space Agency.
The report, titled "U.K. Space Policy", was released earlier
this month by the Select Committee on Trade and Industry of the
British Parliament, after a several-month review of current and
planned space activities in the U.K.
One of the key recommendations of the report was a suggestion
that Britain's space agency, the British National Space Centre (BNSC),
get its own annual budget. Currently, the BNSC is funded by
contributions from a number of other government agencies, rather than
a single budget decided by Parliament.
"BNSC was set up as an ad hoc arrangement in 1985," the report
noted. "It is now time to review the role, status, and organization of
BNSC."
The committee recommended a public review of the BNSC that
could lead to a separate budget for the BNSC. "This review should
also consider the possibility of giving BNSC or its successor body its
own budget, in addition to the existing budgets of BNSC's partners, in
order to ensure that the U.K. space program reflects the long term
public policy interests of the U.K."
In any case, the committee stated in its report that British
space efforts should receive more funding. They noted that current
civilian space funding -- about 181 million pounds (US$275 million) in
1999-2000 -- is not only a smaller fraction of the nation's gross
domestic product than many other nations, including France, Germany,
Canada, Japan, and the U.S., but is less in inflation-adjusted amounts
than the mid-1990s.
"Unless it is suggested that funding has achieved an
abnormally low rate of return," the committee concluded, "it is
evident to us that if the U.K. is to play a significant role in global
space activities, there will need to be an increase in the U.K.
Government's expenditure on civil space over the next planning
period."
The committee recommended that additional funds be used not
just to extend current programs, but to develop new programs. As an
example, the report referred to Beagle 2, the British-developed lander
for ESA's Mars Express mission. The government did provide some
funding for Beagle 2 last year, but project officials are still
working to raise private funding for the full cost of the mission.
"Beagle 2 is an example of an innovative approach to funding
and of a project which seems to have won funding despite, rather than
because of, the system," the committee noted. "It would be a sad
comment on the seriousness of the U.K. contribution to space science
if the necessary funding could not be found. The project is entitled
to expect Government support in finding ways to fill the funding gap
which we understand has yet to be filled."
The committee also noted the U.K.'s lack of participation in
launch vehicle development, be it work on the Ariane 5 or technology
development of future reusable launch vehicles. "The general
perception among all those involved is that the Government and BNSC
are following a policy of no involvement in launchers," the committee
concluded. "It is our strong impression that in BNSC there is a less
than open mind on the case for Government assistance to launcher
development."
While the committee recommended that Britain do more in space,
it did not necessarily conclude it should do more with ESA, even
though the U.K. is not generally perceived as a major player within
the multinational space agency.
"Any withdrawal from ESA programmes would have serious
detrimental consequences for the UK space industry," the committee
recommended. "However, if the UK space budget is increased by a
significant amount, careful consideration should be given as to
whether this increase should redress the current balance of national
as against ESA spend."
The committee's differences with ESA stem from the space
agency's policy of "juste retour", where the number of contracts a
participating nation receives from an ESA program is in proportion to
the amount of funding that nation provides. While Britain has done
well under juste retour, British officials argue that it is not the
most efficient way to do business.
"We think that these things should be settled on the basis of
who is the best person to do the work, rather than trying endlessly to
balance exactly the amount coming back in work versus how much you put
in," the report quoted Lord Sainsbury, British science minister.
While the U.K. does have a space policy, the committee
concluded the policy only supports the status quo, and that the nation
needs to do more related to space. "The latest space strategy
document is admirable in many respects but limited in ambition. We
hope that its successor will be able to announce something beyond a
modest continuation of existing programs, and that the civil space
program will be funded on a less cautious basis."
X-34 Program Resumes Tests
After nearly a year of upgrades and reviews, NASA's X-34
experimental rocketplane resumed tests this month with a series of tow
tests on the ground.
The X-34 A-1A vehicle started a series of ground tests on July
20 when the vehicle was towed behind a truck and then released,
coasting down a runway at Edwards Air Force Base, California. Two
tests were conducted on July 20, with the vehicle traveling just eight
and 16 kmph (5 and 10 mph). Two more tow tests were held on July 24,
with the vehicle reaching peak speeds of 16 and 50 kmph (10 and 30
mph).
The tests are designed to simulate conditions after an X-34
landed, project officials explained. "The tests, which simulate the
vehicle抯 roll-out after landing, will verify the craft抯 guidance and
navigation system, nose wheel steering, braking, rudder speed brake
operation and rudder steering," said Jeff Sexton, flight testing and
operations project manager.
No problems have been reported with the tests to date. "We
are very pleased with the results of these early tests," said Sexton.
"If we have any vehicle anomalies we want to find them in ground tests
not in flight or landing."
NASA is planning six weeks of tow tests of the X-34 at
Edwards, gradually increasing the length and speed of the tests.
Project managers said they eventually want to tow the vehicle for 3,
000 meters (10,000 feet) down the runway, reaching speeds of 130 kmph
(80 mph).
The tests are the first for the X-34 since the vehicle
completed an initial set of "captive carry" flights last September,
when the vehicle was attached to the underbody of an L-1011 carrier
aircraft. Those tests flights were required to obtain FAA
certification for later drop tests. Those tests were performed with
the same X-34 vehicle, then known as A-1. After the captive-carry
flights the vehicle was upgraded to allow it to perform tow and glide
tests, and renamed A-1A to reflect these upgrades.
Those captive-carry tests will resume after the tow tests are
completed so that FAA certification work can be wrapped up. NASA is
then planning a series of unpowered approach and landing tests of the
X-34 at White Sands Missile Range in New Mexico. During those tests
the X-34 will be released in flight from the L-1011 and glide to a
runway landing.
The date those unpowered drop tests, or later powered flight
using the X-34's Fastrac engine, have yet to be announced by NASA.
The schedule for the flight tests has been pushed back repeatedly,
most recently by a review of the program prompted by the failures last
year of two Mars-bound spacecraft. The tow tests that began this
month were previously slated to begin back in February.
The X-34 is a suborbital vehicle designed to test the
technologies that may be needed by later reusable launch vehicles. In
powered flight the vehicle will reach speeds of Mach 8 and altitudes
of about 75,000 meters (250,000 feet). The powered flight tests will
be made with two other X-34 vehicles, A-2 and A-3, currently being
assembled by contractor Orbital Sciences Corporation.
The X-34 is one of three vehicles -- the X-33 and X-37 being
the other two -- NASA is working with industry to develop that will
test technologies and operational methods for reusable launch vehicles
that promise the lower the cost of space access below $2,200 per
kilogram ($1,000 per pound.)
NEAR Starts Moving Away from Eros
After five months of maneuvers that moved it closer to the
asteroid Eros, NASA's NEAR Shoemaker spacecraft started moving away
from the asteroid this week.
The spacecraft fired its main engine for 23 seconds at around
1 pm EDT (1700 UT) Monday, July 24. The maneuver moved the spacecraft
from an orbit just 35 to 39 kilometers (22 to 24 miles) from the
center of the asteroid into an elliptical one that varies from 35 to
50 kilometers (22 to 31 miles).
The maneuver is the first in a series that will push NEAR
farther from the asteroid. A second maneuver on July 31 will
circularize the spacecraft's orbit at an altitude of 50 kilometers
from the asteroid's center. Maneuvers planned for August and
September will eventually carry NEAR out as far as 200 km (124 mi.)
from the asteroid.
NEAR has been in the 35-kilometer orbit since just July 13,
gathering data about the asteroid's gravity field, which will help
scientists understand the density of the asteroid's interior, as well
as high resolution mapping of the surface and its elemental
composition.
From the higher orbits NEAR Shoemaker will be in for the next
few months, scientists will study the asteroid from a global
standpoint, including studying regions of the asteroid's southern
hemisphere that were hidden in shadow earlier in the mission.
NEAR will return close to Eros as its mission winds down at
the end of this year and the beginning of next year, coming perhaps
within a few kilometers of Eros' surface. Scientists have even
discussed landing NEAR on Eros at the end of its mission next year.
DS1 Repairs to Allow Comet Flyby
A software fix that turned a scientific camera into a star
tracker will allow the Deep Space One (DS1) mission to make its
September 2001 flyby of a comet, NASA announced Thursday.
The flyby of comet Borrelly had been in doubt since November,
when the spacecraft's star tracker, an instrument that monitors a set
of reference stars to determine the spacecraft's orientation, failed
after a series of intermittent problems. Without the data from the
star tracker, DS1 entered a safe mode that halted normal operations.
Engineers worked for several months to develop software that
would turn the spacecraft's scientific camera into a star tracker,
even though the camera has a far smaller field of view and works more
slowly than the star tracker. The software was uploaded to the
spacecraft last month and successfully tested.
With a replacement star tracker in place, the spacecraft was
able to turn on its ion engine that had been idle since the star
tracker failure. After a short engine test June 21 and a week-long
test that started June 28, NASA gave the go-ahead to resume DS1's
mission towards Borrelly.
"NASA decided that it could afford to go ahead with a risky
extended mission," said Paul Hertz, DS1 program executive as NASA
headquarters. "The talented Deep Space 1 folks at JPL are working hard
to squeeze a bonus science mission, an encounter with Comet Borrelly,
out of this already successful mission. Although there is no guarantee
of success, trying for the comet makes much more sense than just
turning the spacecraft off."
The timing of the fixed star tracker was critical: if it had
not been repaired by this month, DS1 would not have been able to reach
Borrelly since the ion engines need to run continuously for many
months in order to reach the comet.
"In a very short time, the spacecraft operations team
developed a very complex and innovative new system that gives Deep
Space 1 a new chance to try to reach the comet," said project manager
Marc Rayman. "The new system is working beautifully. I think this is
one of the most impressive in-space rescues ever completed."
DS1 will take images of comet nucleus and the environment
around it as it flies past Borrelly next September, as well as measure
charged particles in the vicinity of the comet and collect infrared
spectral data to determine its composition.
DS1 was originally scheduled to make two comet flybys when its
extended mission began last September, but the star tracker failure
meant that a January 2001 flyby of comet Wilson-Harrington had to be
scrapped.
DS1, launched in October 1998, was primarily designed to test
a suite of a dozen advanced technologies intended for future missions,
ranging from its ion drive to an autonomous computer control system.
Ironically, DS1's star tracker, while of an advanced design, was not
among those dozen technologies the spacecraft was to test. DS1
successfully tested all of those advanced technologies last year and
wrapped up its primary mission with a flyby of asteroid 9969 Braille a
year ago.
Titan 4 Changes Boost Lockheed Martin Profits
Changes in the Titan 4 program helped increase profits for the
space systems division of Lockheed Martin in the second quarter, the
company reported last week.
The company's space systems division recorded earnings of $128
million for the second quarter, compared to $66 million for the same
quarter a year ago. For the year to date the division earned $196
million, down from $230 million a year ago.
The company said that a restructuring of its Titan 4 launch
contract with the U.S. Air Force played a major role for the increased
earnings in the second quarter, along with the absence of a $90
million charge the company took last year in the wake of a pair of
Titan 4 launch failures in April 1999.
"Performance improvements resulted from the successful
implementation of corrective actions and initiatives since the Titan 4
launch failure in April 1999," the company explained in a statement.
"These adjustments resulted in an improvement to pretax earnings in
the second quarter of 2000 of approximately $50 million."
The Titan 4 improvements were partially offset, however, by
startup costs for the Atlas 5, the company's new Evolved Expendable
Launch Vehicle (EELV) program, as well as lower volume for its
military and commercial spacecraft.
The year-to-date earnings are lower than last year's largely
because of a $35 million charge the company took on its Atlas launch
vehicle program last quarter, reflecting "marketing and pricing
pressures" on the booster. A lower volume of government satellite and
launch vehicle activity was also blamed by the company for the decline
in revenues, although it has been partially offset by an increase in
commercial activity, the company reported.
Overall, the company reported second-quarter profits of $42
million, compared to a $41 million loss in the same quarter a year
ago. The company's profits for the quarter would have been
considerably higher, but the company had to spend $150 million at the
end of the quarter to cover its share of a $250 million line of credit
it guaranteed for Globalstar. Globalstar drew on that line of credit
in late June, requiring Lockheed Martin and others to repay the bank.
The company expects Globalstar to repay the $150 million at an
unspecified date.
While it contributed little to the bottom line of the company,
executives singled out the successful inaugural launch of Atlas 3A
booster in May as one of the highlights of the quarter. "We are
exceptionally pleased with accomplishments in the second quarter
including, among others, achievement of a record backlog, increased
cash flow outlook and the successful inaugural flight of the Atlas 3,"
said company chairman and CEO Vance Coffman.
SpaceViews Event Horizon
Note: You can now add these events to your Palm handheld by clicking
on, or copying and pasting into a Web browswer, the URL below each
event. Visit Coola's Web site at http://www.coola.com/ for more
information about this free service.
August 6 Soyuz launch of a Progres resupply spacecraft for the
Mir space station from Baikonur, Kazakhstan.
http://www.coola.com/cgi-bin/addinfo.cgi?pid=10003&rid=964262784&type=D
August 9 Soyuz launch of the second pair of Cluster II
spacecraft from Baikonur, Kazakhstan, at 7:02 am EDT
(1102 UT)
http://www.coola.com/cgi-bin/addinfo.cgi?pid=10003&rid=964262852&type=D
August 10-13 Third International Mars Society Convention, Toronto,
Ontario
http://www.coola.com/cgi-bin/addinfo.cgi?pid=10003&rid=963829496&type=D
August 16 Titan 4B launch of a classified military payload from
Vandenberg Air Force Base, California, between 10pm
and 2am EDT (0200 and 0600 UT August 17).
http://www.coola.com/cgi-bin/addinfo.cgi?pid=10003&rid=963829425&type=D
Other News
Iridium Suitor Backs Away: Merchant bank Castle Harlan has withdrawn
a proposal to purchase the assets of bankrupt satellite phone company
Iridium for $50 million, the bank announced Friday. The bank said in
a statement that "our due diligence and marketing studies were unable
to confirm that Iridium would generate even low levels of revenue with
a high degree of certainty." Although another investment firm,
Venture Partners, has expressed an interest in purchasing Iridium's
assets, including its constellation of over 70 satellites and a
worldwide network of ground stations, Castle Harlan's withdrawal may
hasten plans to deorbit the satellites.
Panspermia Experiment: A sounding rocket flight last week tested
claims that life on Earth was seeded by microbes in outer space. The
rocket, launched Wednesday from White Sands, carried samples of the
microbe Archaea on a suborbital trajectory into space to see how the
microbes withstand exposure to extreme ultraviolet radiation from the
Sun. The microbes are one of a class of "extremophiles", life forms
which can withstand high temperatures, radiation, and chemical
conditions that would be fatal to other life forms. If the microbes
do survive the flight, it will be a small step forward for a theory
known as panspermia, whose proponents believe that the Earth was
seeded with life by microbes like Archaea that were able to survive
the harsh conditions of space. While panspermia is not widely
supported in the general scientific community, it does have some
supporters, including the famous British astronomer Fred Hoyle.
Partial Solar Eclipse: Observers in portions of the northwestern
U.S., Canada, Russia, and Europe witnessed a partial solar eclipse
July 30/31. The greatest coverage of the Sun could be observed in
Greenland, with about 60 percent of the Sun covered by the Moon, while
those in the northwestern U.S. saw a sliver of the Sun eclipses during
sunset. The eclipse was the second partial solar eclipse in July,
after a July 1 eclipse only visible near the south pole. The last
time two solar eclipses could be seen in one month was in December
1880; it will not happen again until December 2206.
Attack of the Killer Space Fungus: It sounds like a bad science-
fiction movie, but Russian scientists insist to SPACE.com it's true: a
mutating fungus is taking over the interior of the Russian space
station Mir. Cosmonauts who spent two months on Mir earlier this year
found the view from a porthole on the station was being obscured by a
film of fungi that were growing on, and even damaging, the window's
surface. Cosmonauts also found that electronics equipment on the
station has been damaged by fungi. Russian scientists believe that
the fungi are ordinary, less harmful terrestrial species that have
mutated under exposure to radiation while in orbit. "Regular and
relatively harmless microbes can dramatically change their
characteristics in extraterrestrial conditions," said researcher
Natalia Novikova.
Asteroid Impact Overdue: A British group of scientists believes that
the Earth is overdue for a major asteroid impact, the Sunday Times of
London reported July 23. According to scientists, an asteroid at
least 1 km (0.6 mi.) in diameter should strike the Earth once every
100,000 years, but there is no evidence of such an impact for at least
that long. The group, the Near Earth Objects Taskforce, is wrapping
up work on a report on the threat of asteroid impacts and the ways to
deal with the threat for the British government. the report is
expected to be released in the near future.
*** Reviews ***
Space Cowboys: Armageddon for the Geritol Set?
by Jeff Foust
The genesis of the movie Space Cowboys can clearly be traced
to two separate events in the year 1998. One is the flight of John
Glenn on shuttle mission STS-95, which showed that an elderly man can
withstand the rigors of spaceflight. The other is the release of the
movie Armageddon, where a group of oil drillers are called upon to
save the world from an incoming asteroid. Combine the two and you end
up with Space Cowboys, where a group of elderly astronaut wanna-bes
are called upon to save the world from a falling satellite.
The movie starts in 1958, where Frank Corvin (Clint Eastwood)
and three other Air Force officers (Tommy Lee Jones, James Garner, and
Donald Sutherland) comprise Team Daedalus, a project to test flight at
the limits of space. However, their hopes of flying into space
themselves are dashed when responsibility of manned spaceflight is
transferred to a new agency, NASA. Corvin and Team Daedalus can only
watch as NASA trots out the first American that will fly into space: a
chimpanzee.
Fast-forward to the present day. Ikon, a giant Russian
communications satellite dating back to the Cold War, is falling out
of orbit. With its guidance system malfunctioning, Russia asks NASA
to send a shuttle mission to the satellite to repair the guidance
system and reboost the satellite; otherwise, the satellite will burn
up in the atmosphere, with dire consequences, a Russian general warns.
Since Russia is a key partner in the International Space Station, NASA
acquiesces.
The problem with the repair is that Ikon uses an old guidance
system, and one apparently copied from the American design.
Fortunately, the designer of that guidance system is still alive:
Frank Corvin. Corvin rejects a NASA request to train astronauts to
repair the system, but provides a counterproposal: send him -- and the
rest of Team Daedalus, all now pushing 70 -- on the shuttle mission to
fix the satellite. Left with no other options, NASA "project manager"
Bob Gerson (James Cromwell), who has an acrimonious history with
Corvin dating back to Team Daedalus' heyday in the 1950s, reluctantly
agrees. (Is it only coincidence that the name "Bob Gerson" looks a
lot like "Dan Goldin", the name of the current NASA administrator? If
not, Goldin should not be flattered...)
Much of the movie will look familiar to those who saw
Armageddon: a mixed crew of regular NASA astronauts and outsiders --
here, Team Daedalus -- are thrown together to train for an impossibly
short period of time for the mission. There are the expected set of
gags from medical tests and flight training, which end up showing
that, surprise, surprise, the old folks do have the right stuff.
NASA did cooperate with the filming of Space Cowboys, allowing
scenes of the movie to be filmed at the Johnson Space Center and
Kennedy Space Center. The film's technical advisors include former and
current astronauts Gordon Fullerton and Robert Cabana, so that while
the movie's premise may strain credibility, many of the details of the
movie make some sense. While not a special effects blockbuster, the
portion of the movie that takes place in space features visuals at
least realistic enough not to be a distraction.
Special mention should go to supporting cast member William
Devane, who plans flight controller Gene Davis. Much of Devane's role
in the movie is to ask questions that many members of the audience no
doubt asked at key moments in the movie (like how an American guidance
system ended up in a Soviet satellite.) At least the producers of the
movie (as well as Eastwood, who directed as well as starred) were
aware that without such questions, the plot line might stretch the
limits of the audience's credibility.
Although many aspects of the plot of the movie are predictable
to one degree or another (and won't be revealed here to avoid giving
too much away), the movie is still enjoyable, particularly as Team
Daedalus fulfills their dreams of spaceflight after waiting 40 years.
With a running time of about two hours, the movie neither drags on too
long or wraps up too early. If you don't mind a few flashbacks to
1998, then Space Cowboys will be a fun trip to the movies for the old
and young.
Space Cowboys opens Friday, August 4 in North America and is
rated PG-13. More information about the movie is available at its
official web site, http://www.spacecowboys.net.
========
This has been the July 31, 2000, issue of SpaceViews.
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