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发信人: bage (网事如疯·春心萌动), 信区: AerospaceScience
标 题: SpaceViews -- 2000 November 27(转载)
发信站: 哈工大紫丁香 (2000年12月22日22:20:57 星期五), 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 2000.48
2000 November 27
http://www.spaceviews.com/2000/1127/
*** News ***
China Offers Peek at Secret Space Program
Russian Ultra-Nationalists Fight to Save Mir
Mir Cosmonauts Lament and Laud the Deorbiting of Station
NBC Holds Hope for Mir Reality Show
Russia Loses Contact With QuickBird 1 Satellite
Delta 2 Lofts Earth-Observing, Argentine Satellites
Ariane 4 Successful on 11th Mission This Year
NASA's Stardust Spacecraft Survives Solar Flare
Launch Pushed Back for Sunbathing Spacecraft
SpaceViews Event Horizon
Other News
*** Articles ***
Hubble Telescope: Has NASA Learned Its Lessons?
Spacecraft Once More Unto the Breach
Space Shuttle Transportation: The Only Way to Fly
*** News ***
China Offers Peek at Secret Space Program
by Paul Eckert
Reuters
for SPACE.com
China said on Wednesday it aims to achieve manned space
flights and become a leading player in space exploration and commerce
in coming decades, building on a mostly home-grown rocket and
satellite program.
A cabinet "white paper" on space set out ambitious goals for
manned space flight, commercial satellite launches and the
industrialization of space, while hailing achievements of China's low-
budget space program and cataloguing its increasingly sophisticated
stock of space hardware.
However, the paper -- "China's Space Activities" -- gave no
space budget figures and shed no new light on Chinese plans to become
the third nation after the former Soviet Union and the United States
to put a person in space.
Referring to a prestige project that has gathered steam with
the successful launch in November last year of China's first
experimental spaceship, Shenzhou, the cabinet paper put realizing
manned spaceflight among the goals for the coming decade.
A goal for the next 20 years or so, the cabinet said, was to
establish a Chinese manned spaceflight system for scientific and
technological experiments and to give China "a more important place in
the world in the field of space science."
Last year, China announced a four-step manned spaceflight
plan, with the aim of establishing a space station served by shuttle-
style vehicles.
Independent achievements highlighted
China aimed to industrialize and commercialize space to
bolster "comprehensive national strength" in the areas of economics,
state security and technology, the paper said.
The white paper, issued on state-run Xinhua news agency,
appeared to address obliquely accusations, which China has angrily
denied for several years, that it upgraded its rocket and satellite
launch capabilities with stolen U.S. technology.
China forged a successful space program on its own, beginning
in 1956 with "weak infrastructure industries and a relatively backward
scientific and technological level," it said.
"In the process of carrying out space activities
independently, China has opened a road of development unique to its
national situation and scored a series of important achievements with
relatively small input and within a relatively short span of time,"
the paper said.
Aerospace officials have boasted that China's spending on
space technology over the past 40 years has been equivalent to the
amount spent by advanced space-faring countries in one year.
Beijing would persist with a policy of "independence and self-
reliance" in developing its space program, it said, noting that since
1970, China has built and launched its own satellites for purposes
such as communications and weather forecasting.
Peaceful intent stressed
Against the backdrop of China's accusations that a U.S.
missile defense proposal would turn outer space into a battlefield --
and fears in Asia about Chinese rockets -- the cabinet stressed a
commitment to peaceful uses of outer space.
China had always "upheld that the exploration and utilization
of outer space should be for peaceful purposes and benefit the whole
of mankind," the white paper said.
China, which has launched satellites for U.S. and Brazilian
operators, among others, and is vying for a bigger slice of the rich
world market for launching commercial satellites, aimed to boost space
cooperation with Asia-Pacific and developing countries, it said.
Among Asian countries, China had agreed to cooperate with Iran
and Pakistan on satellite activities, the paper said, but gave no
details.
Iran and Pakistan came under U.S. sanctions on Tuesday for
receiving missile technology transfers from China.
But the U.S. State Department, citing Chinese pledges to
control missile exports, waived sanctions against China, allowing the
United States to resume processing licenses for commercial space
cooperation with Chinese companies.
Russian Ultra-Nationalists Fight to Save Mir
By Yuri Karash
Moscow Contributing Correspondent
SPACE.com
On Thursday, members of Russia's ultra-nationalist Liberal-
Democratic Party put forward a resolution in the Duma, the lower
chamber in Russia's parliament, aimed at rescuing the Mir space
station.
The resolution was initiated by Alexei Mitrofanov, a
representative of Liberal-Democratic Party of Russia, the ultra-
nationalist organization headed by Vladimir Zhirinovsky.
Communist party deputies and veteran cosmonauts Vitaly
Sevastianov and Svetlana Savitskaya supported this resolution.
The document called on the Russian government to find both
budgeted and extra-budgetary means ($200-250 million overall) to
support the continuous manned operation of the Mir space station.
The resolution was approved during the second reading.
The resolution follows the November 16 announcement by Yuri
Koptev, the general director of the Russian Aviation and Space Agency
(Rosaviakosmos) that the space station would be crashed into the
Pacific Ocean on February 27 or 28, 2001.
The station will be brought out of orbit and back to Earth
over the Pacific Ocean 900 to 1,250 miles (1,500 to 2,000 kilometers)
from Australia, Koptev said at a news conference.
"Right now we are at such a stage in the operation of Mir that
any of its systems could well fail at any time," Koptev said.
NASA officials who have long felt that Russia was diluting
resources needed for the fledgling International Space Station program
by prolonging Mir's life welcomed the announcement.
The Mir has been a source of national pride for Russia, and
has served as a training ground for American and Russian astronauts.
One benefit to life sciences studies provided data used to analyze the
effects of space on the bone structure of Mir astronauts over several
months in orbit.
Mir Cosmonauts Lament and Laud the Deorbiting of Station
By Yuri Karash
Moscow Contributing Correspondent
SPACE.com
With the announcement that the Mir space station will be
dumped into the Pacific Ocean in February 2001, cosmonauts who once
served on the orbiting warhorse believe that while its death was
inevitable, its legacy will endure.
"She was a good ship," veteran cosmonaut Vladimir Titov told
SPACE.com. Titov was one of two cosmonauts who made world's first
year-long mission to the station in 1988. "I believe, Mir could fly
for at least three more years. But if Russia doesn't have the money to
keep both stations (Mir and the International Space Station) in orbit,
it should go for the ISS."
"Russian has currently no alternative to its participation in
ISS program," agreed Vladimir Dezhurov, Mir's commander during its
first docking with Space Shuttle in June-July 1995. "I feel sad about
Mir but we have to look into the future."
On Thursday, November 16 Rosaviakosmos, the Russian space
agency announced that Mir would be crashed into the Pacific Ocean on
February 27 or 28.
The station will be brought out of orbit and back to Earth
over the Pacific Ocean 900 to 1,250 miles (1,500 to 2,000 kilometers)
from Australia, Yuri Koptev, the general director of the Russian space
agency said at a news conference.
Sergei Zaletin, Mir's last commander, told SPACE.com that he
felt that all the work he did during that final mission, which went
April to June of this year, would be wasted.
"Sasha (Alexander Kalery, Mir's last flight engineer) and I
spent a lot of time tuning the station's equipment, fixing it, looking
for an air leak in one of Mir's module and sealing it," Zaletin
recalled. "I wish another crew could have make use of the results of
our flight."
For Sergey Avdeev, the veteran cosmonaut who in the course of
his career spent almost two years on the station, the destruction of
Mir goes hand-in-hand with the Russian space industry's current
dormant period.
"The decision is a reflection of the existing status quo in
the Russian space industry," Avdeev told SPACE.com. "The manufacturing
and designing cycle in the field of rocket-space technology lasts
about eight months. That means that any action in this field must be
prepared at least eight months in advance. Since no Soyuz- or
Progress-type spacecraft were earmarked in mid-1999 for the continuing
operation of Mir beyond 2001, Russian has no choice but to deorbit
Mir."
"I feel sorry that none of Mir's extremely valuable and unique
equipment could be transferred to ISS," said Avdeev.
According to Avdeev, "it would be desirable to have two
operational space station in orbit, like the Soviet Union had for a
while with both Salyut-7 and Mir."
Russia made several attempts to integrate Mir into the ISS
program. The first attempt took place in 1995, when Russia proposed to
use the then ten-year-old outpost's core module for the ISS instead of
Zvezda, a new service module. Even though Mir proved itself a robust
and effective science platform, U.S. politicians made it clear that
using the Mir core module instead of the Zvezda service module was not
an option.
Another attempt to link the two programs was made in November
1998, shortly before the launch of the first element of the ISS, the
Zarya module. Russian space officials wanted to delay its launch by
ten hours. A delay would have allowed the placement of the Zarya
module in the same orbital inclination as Mir, thus facilitating the
transfer of equipment and crews (in case of emergency) between the two
outposts.
NASA objected to this decision. According to Lynn Cline,
deputy NASA associated administrator for External Relations, NASA had
no principal opposition to any Mir integration into the ISS program.
NASA officials did not agree with the Russian plan because "we really
did not understand this decision. It had not been thoroughly explored,
and we have all already agreed on another schedule."
NBC Holds Hope for Mir Reality Show
By David Bauder
Associated Press
for SPACE.com
NBC had big plans for an out-of-this-world reality TV series
from the producer of "Survivor" where American contestants would
compete to go up in space on the Russian space station Mir.
One big problem: Russia's Cabinet decided last week that it
would send the deteriorating Mir hurtling into the Pacific Ocean in
February.
NBC wasn't quite ready to admit Monday that its big idea had
crashed.
"We have every faith in Mark Burnett as a producer, and we
hope that he is able to execute an exciting program for us,"
spokeswoman Shirley Powell said.
Powell wasn't sure what Burnett would be able to do. A
spokesman for the producer, who has been filming "Survivor II" for CBS
in a remote section of Australia, did not return telephone calls
seeking comment.
Its loss would be another blow to NBC, whose programmers have
been scolded by management for not developing a non-fiction series
that has succeeded on the level of CBS's "Survivor" or ABC's "Who
Wants to Be a Millionaire."
NBC had agreed to pay Burnett nearly $40 million for the
rights to "Destination Mir." The idea was to follow a group of would-
be cosmonauts from space camp to a final broadcast, when a winner is
picked and launched into space.
The payment was to include a nearly $20 million sum Burnett
had agreed to pay MirCorp, a Russian company that has leased use of
the space station.
However, Russian Space Agency officials say the 15-year-old
Mir station would be unsafe without new, expensive missions to
refurbish it.
A MirCorp spokesman in the United States, Jeff Lenorowitz,
said the company is trying to persuade Russian President Vladimir
Putin to overrule the Cabinet decision.
"MirCorp hasn't thrown in the towel and is trying to see what
options remain open," Lenorowitz said. He said it was unlikely that
any kind of TV show could be produced without a quick reversal,
though.
Russia Loses Contact With QuickBird 1 Satellite
By Andrew Kramer
Associated Press
for SPACE.com
Russian ground controllers lost contact with an American
commercial satellite on Tuesday after the small craft was blasted into
orbit on a Russian rocket, officials said.
The QuickBird 1 satellite belonged to the Longmont, Colo.-
based company Earth Watch, and was the first of two satellites the
company planned to launch on Russian rockets.
The Russian Kosmos-3 rocket carrying the satellite blasted off
at 2 a.m. Moscow time from the Plesetsk cosmodrome in the Arctic and
made the fiery assent without trouble, the Strategic Missile Forces
press service said. Controllers then lost contact with it.
The Interfax news agency, citing unnamed specialists at the
Russian Aerospace Agency, reported that the second stage of the
booster rocket shut down too early and that the satellite would likely
plunge back into the Earth's atmosphere.
The half-ton satellite was made by another Colorado company,
Ball Aerospace. It was designed to take high-resolution pictures of
the Earth's surface for commercial purposes, such as land management,
mapping and environmental studies.
U.S. companies routinely use Russian space facilities to
launch commercial satellites. The rockets are usually considered
reliable and a good bargain compared with European and American
competitors. The launch Tuesday was the 401st Kosmos-3 blastoff from
the Plesetsk cosmodrome, Interfax said.
Delta 2 Lofts Earth-Observing, Argentine Satellites
By Andrew Bridges
Pasadena Bureau Chief
SPACE.com
After a string of delays, a Delta 2 rocket successfully soared
from an oceanside launch pad at Vandenberg Air Force Base on Tuesday,
ferrying to orbit the NASA Earth Observing 1 and Argentine Satelite de
Aplicaciones Cientificas C satellites.
The Boeing rocket lifted off with its double payload -- a
first for the launch vehicle -- at 1:24 p.m. Eastern Standard Time
(1824 UT). The launch from Space Launch Complex 2 at the California
base came during a fleeting 22-second window.
"We have lift off of the EO-1 and SAC-C satellites, testing
new technologies for the future," said a launch commentator.
The dual payloads -- plus a Swedish nanosatellite --
successfully separated from the rocket at 60, 90 and 110 minutes
following launch.
"They're healthy and looking good," U.S. Air Force Staff Sgt.
Rebecca Bonilla said.
Tuesday's launch came after concerns over paperwork, computers
and contamination conspired to force a series of delays stretching
back to Saturday, pushing the date back each time.
The two satellites lofted as the main payloads should now
complement the Landsat 7 and Terra spacecraft already in orbit, flying
with them in close formation as they trail one another while zipping
around the globe.
Indeed, from Landsat 7 to EO-1 to SAC-C and to Terra, any one
member of the chain will be separated from the others by no more than
30 minutes, allowing all four to act in concert as a single virtual
Earth-observing satellite.
The $178.6 million EO-1 mission is the first of three New
Millennium Program Earth-orbiting missions. The satellite carries
three instruments: an advanced land imager; a hyper-spectral imager;
and a linear imaging spectrometer that can correct for atmospheric
distortion.
The $45 million SAC-C, a joint effort between Argentina, the
United States, Brazil, Denmark, France and Italy, hosts 11 different
instruments.
A majority of the instruments aim to unravel the powerful
influences on Earth from the Sun, as well as study our planet's
environment and ecology. SAC-C is the first deployable satellite
launched by the Argentine Commission on Space Activities (CONAE).
Also tucked aboard the Delta 2, but receiving a much less
impressive billing, is Munin, a Swedish nanosatellite.
The 6-kilogram (13-pound) satellite will collect data on the
auroral activity in both the Northern and Southern Hemispheres,
providing further data that can assist in the prediction of space
weather.
The satellite, named for one of the Norse god Odin's ravens,
was designed and built by the Swedish Institute of Space Physics in
cooperation with students at Sweden's Umea and Lelea universities.
Ariane 4 Successful on 11th Mission This Year
by the Associated Press
for SPACE.com
An Ariane 4 rocket successfully placed a Canadian
telecommunications satellite in orbit Tuesday after the 11th
successful launch of the carrier this year.
The rocket took off just before 9 p.m. local time from its
South American base in Kourou, French Guiana. The Anik F 1 satellite
was placed in orbit 21 minutes and 46 seconds later.
Ariane 4 is the second most powerful in the series of unmanned
European launchers operated by Arianespace, the 13-nation European
Space Agency's commercial arm.
The launch had been delayed for 24 hours after the client
asked for extra checks.
The Anik F 1 satellite weighed 4.8 tons, a record load for an
Ariane 4 rocket. It was built by Boeing Satellite Systems for the
Canadian telecommunications operator Telesat, a subsidiary of BCE Inc.
The satellite, which was placed in orbit above the Pacific
Ocean, will transmit digital signals to North America, South America,
Alaska, Hawaii and the Caribbean during a 15-year period.
NASA's Stardust Spacecraft Survives Solar Flare
by the Associated Press
for SPACE.com
A NASA spacecraft on a seven-year mission to collect comet
dust survived a zap from an enormous solar flare this month.
The Stardust spacecraft was blinded after it was hit Nov. 9 by
a storm of high-energy particles 100,000 times more intense than
usual, according to the Jet Propulsion Laboratory, which manages the
mission.
The spacecraft was 130 million miles away from the sun when it
was hit, the National Aeronautics and Space Administration said. The
flare interfered with the spacecraft's star cameras, leaving it unable
to use its primary method of orienting itself in space.
The spacecraft automatically put itself in standby mode and
waited for communication from Earth. After its first star camera
failed, it tried switching to a second camera but had no success.
Scientists left the spacecraft in standby mode to allow
protons from the flare to diminish, and on Nov. 11 sent commands to
reset the first star camera and turn it back on.
The spacecraft was put back in normal operation several days
later; images taken after the flare subsided showed the camera fully
recovered from the proton hits.
Stardust was launched in February 1999 on a mission to
intercept the comet Wild 2 in 2004, collect dust flying off its
nucleus and return to Earth in 2006 to drop off the samples in a
parachute-equipped capsule.
Launch Pushed Back for Sunbathing Spacecraft
By Leonard David
Senior Space Writer
SPACE.com<
Launch of a spacecraft designed to snag samples of solar wind
will be postponed for several months. NASA has approved the slip for
the Discovery-class Genesis spacecraft, a delay gives breathing room
to teams feverishly working to ready both Genesis and the 2001 Mars
Odyssey mission.
Liftoff of the dinning room table-sized Genesis was set for
February 10, 2001. The space probe's launch has now been pushed to a
tentative launch window of June 6-16, 2001.
The Genesis slip allows teams at the Jet Propulsion Laboratory
(JPL) in Pasadena, California, as well as spacecraft builder Lockheed
Martin Astronautics in Denver, Colorado, to focus more on the Mars
Odyssey spacecraft being readied for sendoff to the Red Planet on
April 7, 2001.
Squeeze play
"It's a decision that we really had to make," said Jay
Bergstralh, who oversees Discovery-class missions at NASA
Headquarters. "This had more to do about getting the Mars '01 mission
launched on schedule in April of next year."
Steven Brody, NASA's Genesis program executive, told SPACE.com
that the decision to delay Genesis is "a prudent management call."
"The Genesis team has been right on track for the February
launch, but we had to take a higher-ground perspective of looking at
the two missions as a whole," Brody said. "There is no science
compromise here. We expect fully to meet all the objectives of the
mission."
"It involves people at the same institutions preparing for
both missions -- Mars '01 and Genesis. As things get tight for
readying Mars '01, we didn't want to run any risk of compromising
either mission," Brody said.
Launch opportunities for Genesis are also available in July
and August of next year. About 10 days to two weeks in each of those
months are available, Brody said.
Sampling the Sun
When Genesis is sent spaceward, it will be plopped into orbit
around a point between Earth and the Sun, a locale where the gravity
of both bodies is balanced.
Genesis would then unfold a set of collection devices, soaking
up particles of solar wind for two years. The particles would be
embedded in ultra-pure silicon wafers.
Once the spacecraft collectors are re-stowed, Genesis would
head for a 2004 rendezvous with Earth.
A special return capsule loaded with the bounty of "cosmic
collectibles" will be lobbed toward a desert site in Utah. The
returning canister would be caught in midair by helicopter, for
eventual transport to the NASA Johnson Space Center in Houston, Texas.
Safely stored and cataloged, Genesis' collection of solar
particles will undergo extensive scrutiny, under ultra-pure, clean
room conditions.
The Genesis mission is designed to provide scientists direct
data on the Sun's composition, as well as help unlock the mysteries of
planetary formation.
Cost hit
There is a cost to NASA in delaying Genesis.
Prior to the launch slip, the entire Genesis mission was cost-
capped at $216 million, including launch vehicle and ground support to
track the mission. What additional costs will have to be swallowed by
NASA has not been fully assessed.
"It is clearly a cost that will be over and above what we have
approved for the Genesis mission," Brody said. "We have to make
decisions in the government on these kind of missions. The money will
have to come out of the space science budget. We'll have to figure out
exactly where the resources come from to cover it."
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.
November 28 Start-1 launch of the Israeli Earth Remote Observation
Satellite EROS A1 from Svobodny, Russia
http://www.coola.com/cgi-bin/addinfo.cgi?pid=10003&rid=975284072&type=D
November 30 Proton launch of the Sirius 3 radio broadcasting
satellite from Baikonur, Kazakhstan at 2:59 pm EST
(1959 UT)
http://www.coola.com/cgi-bin/addinfo.cgi?pid=10003&rid=975284163&type=D
November 30 Launch of the shuttle Endeavour on mission STS-97 from
the Kennedy Space Center, Florida, at 10:01 pm EDT
(0301 UT Dec. 1)
http://www.coola.com/cgi-bin/addinfo.cgi?pid=10003&rid=974072725&type=D
December 4 Atlas 2AS launch of a classified NRO satellite from
Cape Canaveral, Florida at approximately 8:00 pm EST
(0100 UT December 5)
http://www.coola.com/cgi-bin/addinfo.cgi?pid=10003&rid=975284294&type=D
December 8 Ariane 4 launch of the Eurasiasat 1 satellite from
Kourou, French Guiana
http://www.coola.com/cgi-bin/addinfo.cgi?pid=10003&rid=975284379&type=D
Other News
Galaxy 7 Failure: PanAmSat's Galaxy 7 spacecraft, a communications
satellite used mostly as a backup, failed last week, the company
reported. The spacecraft's backup spacecraft control processor
failed on November 22 -- two and a half years after the primary
processor failed -- causing the spacecraft to cease transmissions.
The spacecraft had been used for backup and part-time services from
its position at 125 degrees west longitude since early this year,
after Galaxy 11 was launched to replace it. PanAmSat officials said
that they believe the Boeing 601 (formerly Hughes HS 601) spacecraft
failed because a problem with tin-plated relay switches that can cause
electrical shorts, the same problem fingered in the August failure of
another Boeing 601 spacecraft, Mexico's Solidaridad 1 spacecraft.
Chicxulub Studies: Scientists now have a better understanding of the
forces that work during the impact 65 million years ago that created
the Chicxulub crater in Mexico and has been linked to the demise of
the dinosaurs. Computer modeling by Gareth Collins of Imperial
College in London showed how the impact could create an inner ring
which, while not visible today, has a geophysical signature that
allowed scientists to detect it when they first discovered the crater.
Figuring out how such a ring might form would help researchers
understand the chemical and physical processes that go on during an
impact, and whether and how such events might have caused mass
extinctions in the past.
Obituary: Gerald Soffen, who led the Viking science team that
performed the first experiments on the surface of the planet Mars and
a guiding force in NASA's effort to search for life in the universe,
died November 22 at George Washington University Hospital in
Washington, DC. He was 74. Soffen serviced as project scientist for
the Viking missions in the 1970s while at the Langley Research Center,
and later headed up the Mission to Planet Earth program at the Goddard
Space Flight Center. More recently he served as a special advisor on
astrobiology to NASA administrator Dan Goldin and helped establish the
agency's new Astrobiology Institute. Soffen also created the NASA
Academy, a summer program for college students now in operation at
three NASA centers.
*** Articles ***
Hubble Telescope: Has NASA Learned Its Lessons?
By Leonard David
Senior Space Writer
SPACE.com
Maybe it's not quite the quickie lube job, tune-up, oil change
or windshield wiper replacement that you get from the gas station.
But the trio of in-orbit "fixer-upper" service calls to the
Hubble Space Telescope have shown the value of on-the-spot repairs and
upgrades of aging spacecraft.
Yet the myriad lessons learned in tending Hubble may be lost
in space. That's the view of former astronaut, Bruce McCandless II, a
member of the shuttle crew that dropped off Hubble in Earth orbit in
1990.
"I am amazed with all the improvements on Hubble Space
Telescope servicing that there doesn't seem to be anything coming down
the pike to take advantage of that experience base," McCandless said.
McCandless aired his views in Hampton, Virginia, at a November
14-17 meeting of a NASA-Industry Aerospace Technology Working Group
focused on Earth-orbit infrastructure development.
Spacewalking crews tending to the high-flying telescope have
been able to fix, maintain, update and enhance the facility over the
years. Both ground support teams and astronauts have successfully
increased the productivity of the telescope, while the cost of
Hubble's science results is decreasing, McCandless said.
Disappointing situation
I want to do everything I can to make sure that we don't lose
this capability...this culture," said McCandless. "There are so many
areas where [this experience] can be profitably applied on orbit."
McCandless said abandoning such serviceable spacecraft as the
Compton Gamma Ray Observatory, and the recent NASA decision to abandon
the Extreme Ultraviolet Explorer spacecraft, are disheartening.
"I think the whole situation is very disappointing," said
McCandless, who is now chief scientist for reusable space
transportation systems at Lockheed Martin Astronautics in Denver,
Colorado.
"I'd much rather see us maintain the old vehicles until we get
the new ones in place. We would have this continuity of accommodating
the unexpected, adapting to science as it evolves and taking advantage
of new technologies," McCandless said.
McCandless told SPACE.com that steps must be taken to apply
on-orbit servicing effectively.
"We shouldn't go off and have a total reversion to what, for
lack of better words, I call 慹xpendable satellites.' That's where you
launch something and you have no access to it. So when something goes
wrong, or new technology becomes available, you can't do anything
about it," McCandless said.
NASA reaction
Alan Bunner, science program director for NASA Headquarters,
took some issue with the concerns raised by McCandless. His views were
obtained by SPACE.com in a later phone interview.
"We have a real enthusiastic astronaut corps at NASA and they
do their job very well and they love it," Bunner said. "Our job at
NASA Headquarters is to figure out when is the appropriate time to
involve the astronauts. That's because manned operations don't come
cheap. They are not without risk and we kind of have to hold these
cowboys back."
For the Compton Gamma Ray Observatory, Bunner said that NASA
could not justify astronaut involvement in bringing the spacecraft
back to Earth in a shuttle.
"We had no need to have that spacecraft back. By deploying it
into the Earth's atmosphere we solved the problem of a possible
uncontrolled reentry. That was much, much cheaper and didn't involve
risk to human life. Prudence, budget and safety and other factors just
didn't call for us using the astronauts," Bunner said.
Bunner said that the Extreme Ultraviolet Explorer (EUVE) was
not completely a recoverable spacecraft. "We weren't even sure we
could get up there and get EUVE in time," he said.
"EUVE is a safe mission to just let it naturally reenter,"
Bunner said. "Again, it just didn't make sense for us to involve
astronauts retrieving a mission that had no real need to be retrieved,
" he said.
In the future, Bunner said, NASA will focus on a mixture of
serviceable platforms and throw-away free-flying satellites. He
speculated that far from Earth -- at special gravitational-balance
locales called L-points -- NASA could anchor various science
instruments.
"Eventually there will be a substantial business out there.
Those will be staging areas where astronauts will be needed to go
there and work there," Bunner said.
"I think we make the best use of astronaut skills and
enthusiasm at the appropriate times," Bunner said.
Tool time for telescopes
To date, there have been three Hubble Space Telescope (HST)
servicing missions: December 1993, February 1997 and December 1999.
The next visit to the HST is now slated for approximately
November 1, 2001, said Russ Werneth, HST manager for spacewalks at the
NASA Goddard Space Flight Center in Greenbelt, Maryland.
A follow-on and last service call by astronauts to the
powerful orbiting eye in the sky is on the books for 2003. For now,
2010 is considered the end-of-the-line date for Hubble stellar staring
duties.
Werneth said that 93 hours of astronaut spacewalking time has
been tallied during HST servicing missions. Some 45 items have been
changed out completely, improved, or added to the telescope during
those visits, he said.
The tool kit evolved for Hubble, and the on-orbit techniques
for working on the telescope have paid off tremendously, Werneth said.
In particular, on-the-ground training, as well as underwater practice
sessions, helped assure success in servicing the observatory.
"Train and train, and re-train...that's one of the key reasons
that we've been so successful in the servicing missions," Werneth
said.
Rud Moe, HST servicing mission manager at NASA's Goddard
center, said the ongoing enhancement of the observatory has increased
its "discovery potential," he said.
"It's a real science machine," Moe said. "We're doing more and
more with less and less as we go on," he said.
Moe said future servicing missions should propel HST toward
the 20 year mark of successful operations. "Hopefully, we will have
removed all the infant mortality from the Hubble by that time," Moe
said.
New solar arrays to increase available power, along with
advanced and upgraded equipment, are making Hubble all the more
productive, Moe said.
"You have to add to the lessons learned for Hubble," Moe said,
"not to shy away from the impossible."
Spacecraft Once More Unto the Breach
By Andrew Bridges
Pasadena Bureau Chief
SPACE.com
The annual Leonid meteor shower can be a not-so-gentle
reminder of how small cometary particles can cause trouble for Earth-
orbiting spacecraft.
Each year, without fail, satellite controllers fret the speedy
particles from Comet Tempel-Tuttle will do everything from damage
solar panels, short-out delicate electronic components and -- if well
enough placed -- send a satellite spinning. The particles, like
buckshot sent flying from the blast of a shotgun, are to be ducked at
all costs.
But for a small flotilla of missions already or soon under
flight, there will be no shying from the peril. Instead, the
spacecraft will soon head straight into the breach.
What volleys will meet the four U.S. spacecraft -- Deep Space
1, Stardust, Deep Impact and CONTOUR -- as they fly by a half dozen
comets, remains unknown.
But with the first encounter merely a year away, scientists
are already scrambling to model what dust environment at each target
comet will greet the various probes.
"It's not like going by an asteroid or a planet, which are
quite benign, because comets are actually throwing things at you,"
said Donald Yeomans, a cometary expert at NASA's Jet Propulsion
Laboratory (JPL).
Preserved by the cold of space, comets are made up of ice and
dust left over from the solar nebula, out of which our solar system
formed. Scientists believe these primitive frozen remnants hold the
clues to the solar system's earliest and coldest period.
But as these 4.5 billion-year-old frozen reminders approach
the warming rays of the Sun, they can grow active, often unpredictably
so, as they spew jets of gas and dust.
The European Space Agency (ESA) learned its lesson well during
the March 1986 flyby of Comet Halley by its Giotto spacecraft.
Just seconds before its closest approach to Halley, Giotto was
blindsided by a large dust particle. The impact knocked out several
instruments and sent the spacecraft out of kilter for some 30 minutes.
None of the comets the various spacecraft will visit are
expected to be as active as Halley was, but they are proving tricky
all the same to pin down.
Scientists began meeting last fall to work on modeling comet
nuclei and what the various missions might see -- and image -- of them
during their respective encounters. Missions members met again in
recent weeks at JPL to further tinker with those models, which include
complex matrices they hope will predict the dust environment at each
fickle comet.
"They vary from day to day, week to week and from appearance
to appearance," said Ray Newburn, a JPL co-investigator on the
Stardust mission. Stardust will fly by the comet Wild 2 in January
2004, collecting dust and volatile samples for return to Earth two
years later.
For example, models predict that Deep Space 1, which will make
the first encounter of the bunch when it flies by the comet Borrelly
in September of next year, will encounter a single particle 0.015 to
0.28 inches (0.4 to 0.7 millimeters) in size during the entire flyby.
Although the expected dust flow will be light, a single, well-placed
particle of sufficient size could send the spacecraft spinning.
"If you get a particle impact at an edge, it can impart
considerable torque to the spacecraft," said Marc Rayman, the
mission's chief engineer. Particles could also knock out individual
components or create plasma upon impact that can short-out portions of
the spacecraft.
To lessen the danger, Deep Space 1 will fly into the dust
stream with its solar panels edge-on, thus minimizing the surface area
it exposes to harm.
Unlike the other three missions, however, the probe does not
have the luxury of bumpers called Whipple shields. The shields would
deflect the particles it might meet during the flyby, a bonus tacked
on to the end of the already completed mission. Instead, Deep Space
1's multi-layer insulation is set off from the spacecraft about 2
inches (5 centimeters) to help absorb any impacts.
"We will be somewhat more bold than the other missions will
be," Rayman said.
Assuming Deep Space 1 survives its flyby -- which in all
likelihood will be the spacecraft's swan song, as its on-board supply
of hydrazine is dwindling -- the data it can provide about Borrelly
will be included in the modeling work.
"That information will be factored into the next flyby and
likewise that data will be factored into the next one after that,"
said Yeomans, who has a hand in all four cometary missions.
Should the risks prove larger than expected, mission
navigators -- for the most part, common to all four missions -- can
always set a course that takes the spacecraft farther from the comets.
That might lessen the odds of getting a decent look at the comets'
nuclei, but may mean the difference between a successful flyby and
disaster.
"None of us are flying what we think of as kamikaze missions
by any means," Newburn said. "All of us flying cometary spacecraft
plan to survive."
Space Shuttle Transportation: The Only Way to Fly
By Jim Banke
Senior Producer, Cape Canaveral Bureau
SPACE.com
It is one of the most amazing sights associated with the U.S.
space program.
The vision: a Space Shuttle orbiter, bolted to the back of a
modified 747 jumbo jet, flying low over the beaches of Cape Canaveral
-- or landing to refuel at an Air Force base somewhere between
California and Florida during a cross-country ferry flight.
When it happens, thousands gather to see first-hand the most
recognized symbol of America's space program riding piggyback on one
of the most recognized airliners in the world -- itself a marvel to
watch fly as you wonder how something so big can stay up in the air.
"It's complete excitement," said Gordon Fullerton, a veteran
NASA astronaut who commanded shuttle missions in 1982 and 1985, but
who is more well known around NASA's Dryden Flight Research Center at
Edwards Air Force Base, Calif., as one of the agency's most respected
and experienced research pilots.
Fullerton is entrusted with flying NASA's 747 Shuttle Carrier
Aircraft. He also trains new ferry pilots, including Bill Brockett,
another NASA research pilot, who in early November made his first
landing with the 747 while it carried shuttle Discovery and touched
down on the concrete runway at the Kennedy Space Center (KSC) in
Florida.
"The pressure was on," a smiling and relieved Brockett
reported an hour after making that perfect, career-milestone landing
at KSC.
"Bill did a great job," added Fullerton.
This particular job was required when shuttle Discovery was
forced to land at Edwards on October 24, concluding an assembly
mission to the International Space Station in California after bad
weather on three consecutive days prevented the usual Florida
homecoming.
It was the first time in more than four years that a Space
Shuttle mission had not ended at KSC as planned.
When that happens, NASA's only way to return the 100-ton
glider to its launch site is to bolt the spaceplane to the back of a
747 and ferry it cross-country, an exercise that costs about $1
million and a week's worth of time from the frequently tight launch
schedule.
And there's also some anxiety in a $2 billion orbiter defying
gravity more often than needed.
"There's a certain degree of risk in transporting across the
country like this," said Jim Halsell, a NASA astronaut who currently
is serving as a shuttle program manager at KSC. "I'm nervous only in
the sense that that represents a national resource and something that
we want to take really good care of."
Every time the shuttle takes a ride it's a first class seat
all the way.
In the first place, about 200 people are employed to make sure
the orbiter has everything it needs before, during and after the
flight.
Most of the workers are based at KSC and have to travel out to
the high desert of California on short notice when it becomes evident
that a shuttle mission isn't likely to end in Florida. The travel
expenses for this group represents one of the larger shares of the $1
million cost.
But the trip apparently is no picnic for the technicians,
engineers and managers.
"I would not for a second portray this trip as a vacation or
as even a good deal," Halsell said of the effort in general.
And in the case of the team that supported Discovery's most
recent ferry flight, Halsell said, "Most of the people worked 12-hour
days everyday that they were out there (at Edwards). Both days and
nights were extremely cold, but especially the nights. When you
combine the cold weather and the wind with a little bit of wet
weather, those folks were earning whatever we were paying them, I'm
sure of that."
Another perk the shuttle enjoys during the ride the escort
service. Another jet is chartered to fly about 20 to 30 minutes ahead
of the 747 to find where the ideal weather is so the shuttle doesn't
have to risk flying through clouds or rain that might damage its
fragile skin of heat protection tiles.
Usually that pathfinder jet is an Air Force cargo jet, often a
C-141, which pulls double duty as the airliner which carries the 200
or so KSC workers and their equipment back home.
Why don't they fly aboard the 747? It's one of the most
frequently asked questions and one of the easiest to answer, according
to Brockett.
There are no seats inside.
"It's completely empty except for a couple of racks for
monitoring equipment," Brockett said.
All of the seats, galleys, overhead bins and other features of
a commercial airliner have been stripped out of the 747 to save on
weight, leaving the interior an open cavern with hundreds of square
feet of unused floor space.
"You could host a pretty good party in the cabin of that
airplane," Brockett said.
But not while a shuttle is attached; safety is the other
reason why the number of people allowed on the 747 is limited. A
shuttle that has just returned from orbit still has a lot of toxic
rocket propellant and other hazardous fluids onboard, so it's best to
keep a safe distance away.
During a ferry flight the shuttle is completely powered down
and essentially inert. The spacecraft is empty and there is no way to
separate the shuttle should something go wrong with the 747. This was
not the case during the late 1970s when the prototype shuttle
Enterprise was dropped several times with pilots onboard -- including
Fullerton -- to test the handling characteristics of the shuttle
during landing.
And in all cases -- whether a shuttle is being ferried to
Florida after landing or back to California for routine maintenance at
the factory -- it's impossible to start up the shuttle's main engines
while attached to the 747. This urban myth was fostered in part, by
the opening sequence of the 1979 James Bond movie Moonraker, in which
the bad guys did just that to steal the shuttle from NASA.
NASA actually owns two 747 carrier jets. The first was
purchased from American Airlines in 1974 and has the tail number 905.
It is the more historic of the two in that it was used for all the
Enterprise approach and landing tests and has traveled the world
carrying Enterprise on goodwill tours.
A second 747 was procured from Japan Air Lines via a contract
with Boeing and was introduced in 1991 when it delivered Endeavour
from its factory in California to KSC in Florida.
In order to handle a shuttle, both 747s feature several
modifications, the most visible being the addition of two vertical
fins to the tail of the airplane. This helps keep the plane stable
despite the turbulence that comes from adding a shuttle to its back --
turbulence that is somewhat diminished thanks to a streamlining
tailcone that covers the shuttle's three main engines during a ferry
flight.
"There's a continuous kind of a rumbling throughout the
airframe from the turbulent flow that comes off the back of the
shuttle and hits the tailfeathers," Brockett said.
The drag from the shuttle costs a lot in terms of fuel, too.
According to Brockett, the combination 747-shuttle travels about one-
and-a-half-times the length of the airplane per gallon of fuel.
========
This has been the November 27, 2000, issue of SpaceViews.
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