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发信人: bage (网事如疯·春心萌动), 信区: AerospaceScience
标 题: SpaceViews -- 2000 November 13(转载)
发信站: 哈工大紫丁香 (2000年12月22日22:21:12 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 2000.46
2000 November 13
http://www.spaceviews.com/2000/1113/
*** News ***
Funding to Deorbit Mir Confirmed, Russian Official Says
Air Force Delta 2 Lifts Navstar GPS Satellite Into Earth Orbit
Severe Solar Storm Threatens Airline, Space Travelers
Amateur Space Rocket Prize Goes Unclaimed at the End
NY Congressman Set to Head House Science Panel
Bill Nelson, Space Shuttle Payload Specialist Wins Florida
Senate Seat
Eye in Sky to Track Space Junk
Scientists Examine Artificial Gravity
SpaceViews Event Horizon
Other News
*** Articles ***
Humans On Mars: NASA on the Defensive
Mining Space: Whither NASA?
*** News ***
Funding to Deorbit Mir Confirmed, Russian Official Says
By Frederic Castel
Special to SPACE.com
The Russian government has set aside the $25 million needed to
bring down the Mir space station, an official said Monday.
"The Russian government has already taken the decision to
provide the financial resources needed to deorbit Mir," said Russian
space agency chief Yuri Koptev. The statement runs contrary to some
media reports.
As claimed several times by various officials in the past two
months, Russia plans to bring the 14-year-old orbital outpost down
over the ocean in late February, said Deputy Prime Minister Ilya
Klebanov. A final decision has yet to be made. It also been unclear
whether the funds for deorbiting, not to mention the $200 million that
could bail out the station and keep it operating beyond February and
for another year, were available. The $25 million would cover the cost
of launching an automated cargo spacecraft to Mir, with fuel needed to
safely direct the station to a designated location over the Pacific
Ocean.
"We have to think about the safety aspect of shutting down Mir
and we don't have to make the decision to deorbit Mir when the station
becomes uncontrollable," said Koptev.
The final official decision on the proposal to dump the aging
Russian space station in the Pacific Ocean will come early next year,
he said.
Mir has been losing altitude since a two-man crew left the
outpost in June, and space officials have said it is necessary to
raise its orbit if it is to continue operating well into 2001 to
prevent the 130-ton station from reentering Earth's atmosphere out of
control.
An uncontrollable plunge by Mir is a nightmare that Russian
space officials want to avoid at all costs, since heavy fragments of
the station could fall on populated areas. No space agency in the
world has experience deorbiting such a complex and bulky spacecraft.
The Russian government, which owns Mir but stopped financially
supporting it last year, has leased commercial rights to Amsterdam-
based MirCorp. The private company has spent more than $40 million
this year to keep Mir alive and has scrambled of late to continue
raising funds, announcing plans last month for an initial public stock
offering.
MirCorp's President Jeffrey Manber called Koptev's deorbiting
funds claim a "non-story."
"For three years, the Russian government has said it will
allocate the funds. The problem is they don't have the money," Manber
said. Plans remain intact for businessman Dennis Tito's visit to the
space station, Manber said. Tito put up $20 million for the
opportunity and has trained for the flight. If successful, he'll
become the world's first space tourist.
"We're going to fly Tito in January," Manber said.
Mir's downfall would also be a problem for the producer of an
upcoming reality-based television program, Destination: Mir. Mark
Burnett promised that the show's winner would get a free visit to the
space station.
The termination of Mir's more than 14 years in space also
could end a brewing conflict between the American and Russian space
agencies. NASA openly criticized Russia for continuing to support Mir,
claiming resources to keep Mir going were detracting from Russia's
efforts to meet its commitments to the International Space Station
(ISS).
Ironically, Koptev, who made his comments about the Mir funds
while traveling last week in Paris with Russian President Vladimir
Putin, also said he was happy about the successful installment of the
first crew aboard the ISS.
"From a historical perspective, the arrival of the first
permanent crew aboard ISS this week represents all the efforts
invested since 1992 when we started to talk about bilateral and
international space cooperation," said Koptev. "Even if we don't move
forward as quickly as we'd like to, we still have moved forward."
Air Force Delta 2 Lifts Navstar GPS Satellite Into Earth Orbit
By Jim Banke
Senior Producer, Cape Canaveral Bureau
SPACE.com
History repeated itself in fine fashion today with the
successful launch of an Air Force Delta 2 rocket carrying a military
navigation satellite into Earth orbit.
Liftoff of the Boeing-built booster from Cape Canaveral Air
Force Station came precisely at 12:14:02.219 p.m. EST (1714 UT) and 25
minutes later the Lockheed Martin-built Global Positioning System
(GPS) satellite arrived in its proper orbit and separated from the
rocket.
The Navstar GPS satellites send out a signal that is received
by military and civilian users around the world to help them keep
track of where they are on the planet, what direction they are moving
and how fast they are going.
Today's mission marked the 33rd time this combination of
rocket and cargo was sent into space from the Cape. The first launch
was on Feb. 14, 1989.
"Today's successful launch is a part of a 26-year Boeing
association with the GPS program," said Will Hampton, Boeing's
director of Air Force Delta programs. "Delta 2 launch vehicles placed
the original 24 operational satellites and all replacements for the
GPS constellation into orbit for the U.S. Air Force."
Boeing has been involved in the Air Force's GPS program since
1974, when the company won contracts to build developmental satellites
and receiver sets. Then in 1987 the company won the contract to launch
the satellites, which resulted in the design and introduction of the
Delta 2 rocket.
GPS: The Next Generation
On Thursday officials from the Air Force Space and Missile
Systems Center at Los Angeles Air Force Base awarded Boeing and
Lockheed Martin each with $16 million fixed-price contracts to figure
out how the GPS program will evolve to include some specific new
features for civilians, as well as reduce operational costs.
"These contracts represent the first significant step in
providing the next generation of navigation and timing system
performance for the U.S. warfighter and civil users throughout the
world," Air Force Col. Douglas Loverro, GPS Joint Program Office
director, said in a prepared statement.
Known as the System Architecture and Requirements Definition
contract, the study is to last 12 months and is the first step in a
long process that will lead to launching a new constellation of
satellites beginning around 2009, according to Air Force officials.
Meanwhile, the next launch of a Delta 2 rocket is scheduled
for November 18 from Vandenberg Air Force Base in California. The NASA
mission will feature the launch of Earth Orbiter 1, a technology
demonstration spacecraft that will test new ways of taking pictures of
the Earth for use in managing land resources.
Severe Solar Storm Threatens Airline, Space Travelers
By Robert Roy Britt
Senior Science Writer
and Jim Banke
Senior Producer, Cape Canaveral Bureau
SPACE.com
A severe space weather storm began pounding Earth late
Wednesday and is expected to threaten communications, satellite
operations and possibly astronauts and airline passengers --
especially pregnant women -- through Sunday.
The event began Wednesday November 8 at 6:50 p.m. Eastern
Standard Time (23:50 GMT), when a large solar flare welled up from
deep within the Sun. This energy interacted with the solar atmosphere,
sending a stream of charged particles called protons heading toward
Earth.
"The protons measured near Earth increased 10,000 times in the
matter of a few minutes," said Joseph Kunches, lead forecaster at NOAA
Space Environment Center.
Forecasters labeled the event an S4. The most severe would be
an S5. The event was different from other recent solar storms -- less
likely to generate an increase in the northern lights, forecasters
said. But at the same time it's potentially more dangerous to humans.
The protons buffeting Earth are a form of radiation that, with
extended exposure, is thought to damage DNA and contribute to cancer.
While cosmic radiation from distant sources constantly bombards Earth,
the amount increases during a severe solar storm.
People on the ground are not at risk, as Earth's magnetic
field and atmosphere provide a blanket of protection.
But NOAA says an airline passenger can experience as much
radiation as 10 chest X-rays, though this figure is debated. Experts
do agree, however, that anyone on a high-altitude jet or in space is
exposed to more radiation than someone on the ground.
Wallace Friedberg, who studies the threat for the Federal
Aviation Administration (FAA), said that the NOAA estimates are the
best available. He said most people planning a flight during the storm
should not necessarily change their plans, adding that the radiation
measurements he has seen indicate that this event is not the worst
possible.
"If it was my daughter, and if she was pregnant, I'd tell her
she might want to wait," said Friedberg, who heads the radiobiology
research team at the FAA Civil Aeromedical Institute. "If she's not
pregnant, I wouldn't be that concerned.
Friedberg has a short flight scheduled himself this weekend.
"If I was going today, I would go," he said. "But I'm not pregnant."
High-frequency radio communications will also be strongly
affected through Sunday, when the proton stream is expected to die
down.
Effect on space travelers
The proton stream is strong enough to be dangerous to
astronauts if they are on spacewalks. There are three people --one
American and two Russians, living aboard the International Space
Station.
"NASA is acutely aware of the fact that there is some hazard
to them based on the radiation environment," said NOAA's Kunches. "And
today is one of those days that they need to worry."
NASA says the three crew members aboard Space Station Alpha
(ISS) are in no danger from the event.
However, flight controllers near Moscow have asked station
commander Bill Shepherd and cosmonauts Yuri Gidzenko and Sergei
Krikalev to set up a radiation monitoring device inside the Russian-
built modules as a precaution.
The portable device, similar to those used during each space
shuttle mission, will sound an alarm if it senses radiation that
reaches a preset level, said NASA spokesman Rob Navias.
If that should happen, the three crew members will move to the
end of the Zvezda service module where the Soyuz spacecraft is docked
and remain there until the radiation level subsides. This part of
Space Station Alpha offers the most protection from the hazard, Navias
said.
In any case there is no need for Shepherd, Gidzenko and
Krikalev to move into the Soyuz for protection, nor are there any
plans for the crew to evacuate the station and return to Earth.
"This particular solar flare, even if it reaches the levels
that would trigger that alarm on board, would have no impact to crew
health, or crew safety," Navias said.
But the long-term effects of exposure to cosmic radiation and
solar storms are more worrisome, and not entirely known.
NASA keeps an eye on the amount of radiation an astronaut
accumulates during several missions, and once they hit their limit
they can't fly anymore. What that limit is depends on each crew
member, and because of medical privacy it's never been publicly
announced that an astronaut won't fly because of radiation concerns.
Airline passenger threat
Scientists have known for nearly a century that the effects of
radiation increase with altitude.
There is debate over how much danger an event of this type
poses to airline passengers. But experts agree that any potential
danger depends on the route of the plane.
"If you fly from Philadelphia to Atlanta, it probably isn't
going to have any effect on you," said Kunches, the NOAA forecaster.
"Flights in the polar regions are going to be much more susceptible to
seeing some effects."
Other scientists say the amount of radiation in the atmosphere
can be twice as much at the poles as elsewhere. This is because
Earth's magnetic field channels incoming energy toward the poles.
Even on normal flights in non-storm conditions, researchers
say the risk to unborn babies might be too great if a pregnant women
takes frequent, long flights.
Northern lights
The solar flare also triggered what scientists call a coronal
mass ejection. Energy from this type of event takes two to three days
to reach Earth, and fuels the colorful displays called the northern
lights, or aurora. This storm was not expected to cause significant
auroral activity, however.
"The likelihood of a big magnetic storm is pretty low,"
Kunches said. "It looks like most of the brunt of the material and the
energy is going to go off the west limb [of the sun] and away from the
Earth."
Amateur Space Rocket Prize Goes Unclaimed at the End
By Andrew Bridges
Pasadena Bureau Chief
SPACE.com
As the clock struck midnight on Wednesday, a $250,000 prize to
the first private group to launch a rocket into space expired,
unclaimed.
The challenge of the Cheap Access To Space (CATS) prize:
launch a 2-kilogram (4.4-pound) payload to a height of at least 200
kilometers (124 miles). No "substantial" use of government-derived
designs or surplus hardware was allowed under contest guidelines.
Back in November 1997, when the prize was announced, contest
administrators demanded 30-days' notice of any launch attempt. The 15
or so teams then in contention bristled at the rule, claiming it would
hinder their efforts. Now, a full three years later, only two teams
ever mustered serious attempts to snag the prize.
Neither was successful.
"Nobody won it. That's it. Today's the final day," said James
George, of the Space Frontier Foundation, on Wednesday.
The group, along with the Foundation for the International
Non-governmental Development of Space, saw the contest as a way of
promoting private sector activity in space -- much as the more
ambitious X-PRIZE is doing on the human side of rocketry.
Most recently, the High Altitude Research Corp. launched a
rocket from a balloon-borne gondola sent aloft from the Gulf of Mexico
in what was generally agreed to be the last stab at the CATS prize.
The rocket ignited, but failed to reach an altitude of more than 24
kilometers (15 miles) during the October 29 attempt.
Earlier, JP Aerospace had hoped to gun for the $50,000
consolation prize by sending a rocket to 74 miles (120 kilometers), an
attempt that was scotched by a last-minute bureaucratic "nyet" -- or
at least a launch-delaying "not yet" -- from the Federal Aviation
Administration.
David Anderman, who wrote the CATS prize rules, said the
contest wasn't all a wash, even if the deadline came and went without
a winner.
"Had we not had a deadline I'd suspect we wouldn't have had
any launches," Anderman said. "The teams did not come as far as we
thought when we established the prize, but they did make demonstrable
progress."
NY Congressman Set to Head House Science Panel
By Craig Linder
Special to SPACE.com
When the 107th Congress convenes in the nation's capitol early
next year, the House panel that oversees American space policy will
likely have a new leader.
Rep. F. James Sensenbrenner, the Wisconsin Republican who has
headed the House Science Committee since the GOP took control of the
House in 1994, is considered a front-runner to head the powerful House
Judiciary Committee.
Sensenbrenner is required to relinquish his perch as head of
the Science Committee as the result of six-year term limits that
Republicans placed on committee chairmen in 1994.
Next in line for the top of the Science Committee is Rep.
Sherwood L. Boehlert, a Republican from the upstate New York city of
Utica. Boehlert's district includes the U.S. Air Force's Research
Laboratory in Rome, New York, which specializes in information
technologies.
"It is something we would welcome," Boehlert spokesman Jim
Philipps said. "We've got a lot of ideas about what we'd like to
accomplish on the Science Committee." He declined to elaborate on the
congressman's goals for space issues.
Since the GOP maintained its hold on the House in Tuesday's
elections, the Republican leadership will select committee chairmen.
While seniority typically guides the selection process, House Speaker
J. Dennis Hastert, (R-Illinois) can take issues like geographical
origin and fundraising prowess into account.
Philipps said that Boehlert expects to receive the
chairmanship, but that "nothing is set in stone."
"Boehlert doesn't have desks and chairs picked out up on the
third floor," he said.
Space observers say that Boehlert has a strong record on space
issues and has regularly been a backer of the commercialization of
space and the International Space Station.
Boehlert's chairmanship could be a good sign for
commercialization of the space station, but it's unclear how many
space bills will make it into law given how divided the new Congress
will be.
Beyond space issues, Boehlert has carved out a moderate record
in the increasingly conservative Republican Party during his 18 years
in the House. Much of his signature legislation focuses on
environmental issues, and he is also chair of the House panel that
oversees water resources and the environment.
If Boehlert becomes the head of the Science Committee, House
rules would force him to give up his oversight of the water
subcommittee. Philipps said that the congressman would still be able
to carry out his environmental goals without heading that
subcommittee.
"You could put him in a box and he would still be able to stay
involved with environmental issues," he said.
Boehlert is also an avid fan of the New York Yankees --
perhaps a natural connection for the congressman who represents
Cooperstown, New York, home to the Baseball Hall of Fame.
In 1999, in fact, Boehlert -- who owns a minority interest in
the Utica Blue Sox, a Class A minor league baseball team -- co-
sponsored a successful House resolution to honor Yankee legend Joe
DiMaggio.
Bill Nelson, Space Shuttle Payload Specialist Wins Florida Senate Seat
by SPACE.com staff
Former Space Shuttle payload specialist Democrat Bill Nelson
defeated Republican Representative Bill McCollum on Tuesday for the
Senate seat from Florida.
Nelson, the state insurance commissioner, won the Senate seat
vacated by the retiring Republican Connie Mack in a race that was seen
as crucial to Democratic efforts to overtake the 54-46 Republican
Senate majority.
In 1986, while a Democratic congressman representing Florida's
Space Coast area, Nelson became the second member of NASA's
politician-in-space program, following Senator Jake Garn, a Republican
from Utah.
Aboard flight STS-61C on the shuttle Columbia, Nelson was
involved with a University of Alabama at Birmingham experiment that
hoped to grow crystal proteins in outer space for cancer research and
served as the subject for medical tests examining the effects of
microgravity on the human body.
The space agency chose Nelson and Garn for slots on the
shuttle missions because of their positions on key congressional
panels that oversaw NASA. Nelson was the chairman of the House space
subcommittee and Garn headed the Senate appropriations subcommittee
that oversaw NASA's budget.
Nelson, who left Washington in 1992 to make a bid for the
Florida governor's mansion -- which failed -- already has become one
of the few politicians to make space exploration an issue in the
November elections.
Nelson's campaign centered on a September debate held near
Cape Canaveral about space issues, but both the event's sponsors and
the McCollum campaign demurred, opting to focus on statewide issues.
In August, Nelson told Florida Today that he would make a
piloted mission to Mars a legislative priority.
"In my lifetime, what I want to see is a mission from Planet
Earth to Planet Mars with an international crew that returns safely,"
Nelson told the newspaper. "I think we can do that. We have the
technology, we just have to have the will to do."
During his tenure in Congress, Nelson was an ardent advocate
for NASA and space exploration. He was the prime sponsor on a bill
that would fund construction of the shuttle Endeavor, NASA's
replacement for the shuttle Challenger.
The Endeavor bill may have had some personal significance for
Nelson -- his shuttle flight touched down just 10 days before the
Challenger lifted off on its doomed mission.
Critics say, however, that as a congressman Nelson was too
protective of the space agency, charging that he used his position as
chair of the space subcommittee to act as a booster for NASA, instead
of as an independent check on the agency.
Nelson and the space agency's other backers on the space
committees were "NASA's biggest fans when you get right down to it,"
Donald E. Day, an auditor with the General Accounting Office,
Congress' investigative arm, told the New York Times in a 1986
article.
Eye in Sky to Track Space Junk
By Leonard David
Senior Space Writer
SPACE.com
Space gridlock. It's not quite solar-panel-to-solar-panel
traffic above Earth -- but it is getting crowded as more and more
nations vie for their own space byways.
In a decade's time, nearly 1,500 active satellites are
expected to be circling our planet. That is more than twice the number
beeping away today.
What may be needed is something akin to air-traffic control,
but built for day-to-day steering of satellites, piloted shuttles and
occupied space stations.
After all, a fender bender at spacecraft speeds is no minor
violation. It would be a ticket to disaster.
Spotter scope
A step in the direction of space-traffic control is use of the
Midcourse Space Experiment (MSX) satellite. The just-under $1 billion
Pentagon satellite was launched in April 1996. The spacecraft was
built and equipped to carry out studies for the Ballistic Missile
Defense Organization.
During its primary mission, the MSX used a super-cooled
infrared sensor to detect and track test warheads that were sent
skyward from Earth. That duty ended in February 1997 as the
satellite's on-board coolant supply used to chill the infrared
instrument ran out.
However, a host of other sensors on the spacecraft remain
fully functional.
One of those devices is the Space-Based Visible Sensor. Built
by the Massachusetts Institute of Technology's Lincoln Laboratory in
Lexington, the optical sensor is being used to scan deep space.
The hunt has paid off.
"We're coming up to 150 objects in the last three years that
were completely lost, or nearly lost," said Curt von Braun, program
manger for the MIT Lincoln Laboratory Space-Based Visible Sensor.
"We're blazing a trail here. Nobody else has done this before. This is
the only operational space-based space surveillance instrument," von
Braun told SPACE.com.
Lost and found department
From the MSX vantage point -- now orbiting at 559 miles (900
kilometers) above Earth -- big chunks of space debris and derelict
rocket bodies have been spotted, as have scads of Russian payloads and
a host of commercial communications satellites, some of them wandering
aimlessly through space.
The satellite sensor has proven most helpful in keeping an eye
on highflying spacecraft, particularly in geosynchronous orbit -- some
22,300 miles (35,880 kilometers) above the planet. At that altitude a
belt of satellites from a variety of nations coexist.
The Air Force Space Command has a tough time cataloging and
tracking objects in geosynchronous orbit using their network of ground
equipment, MIT's von Braun said. That ground-up view is also limited
by location, weather and time of day.
Some satellites can drift away from their last known position.
"It becomes a needle in a haystack at that point," von Braun said.
Bump-free belt
For the last three years, the MSX space-scanning sensor has
reduced the number of lost satellites in key orbits from 63 to 13,
said Roger Sudbury, a spokesman for Lincoln Laboratory.
Given the ability of MSX to better track objects in high-
altitude satellite orbits, the spacecraft has been handed over to the
Air Force Space Command. It is now part of the Space Surveillance
network, Sudbury said.
Von Braun said use of MSX for space surveillance from orbit
has had a big impact.
The U.S. Air Force would like to begin orbiting a small
constellation of spacecraft by 2010, said von Braun, tasked to keep an
eye on the surrounding space that each satellite zips through -- over
and under.
Can a space-based satellite-traffic control system be far
behind?
"I think it's possible. This is the beginning of such an idea.
You obviously have to know where everything is," von Braun said.
While a dedicated space-traffic control may be many years off,
von Braun said that keeping an eye on geosynchronous orbit is a start.
"Everyone in the geosynchronous belt has certain positions
that they've been allocated. Each entity must remain within those
positions. Nobody wants to bump into other things," von Braun said.
At present, the Air Force Space Command in Colorado Springs,
Colorado has the charter to keep an eye on the whirling whereabouts of
both military and civilian spacecraft, as well as chunks of space
junk.
"Traffic control is a term used quite often, in conceptual
terms. We don't really know what that term means as yet," said
Nicholas Johnson, chief scientist in NASA's orbital debris program
office at the Johnson Space Center in Houston, Texas.
At what time the capacity of the current network of ground-
based sensors might be exceeded is unknown, he said.
Orbital tracks of the space shuttle and the International
Space Station are closely monitored, Johnson said.
Program managers are advised of any collision avoidance
maneuvers that may be required.
In the past, Johnson said, several shuttle orbiters had to jet
themselves out of harms way to avoid any prospect of running into
derelict debris. "But very few other spacecraft ever do that," he
said.
MSX has proven the concept of space-based space surveillance,
he said. However, space-traffic control is not, at this time, a
pressing issue, Johnson said. "My personal assessment is that it's
going to be a few more years before people get serious about what we
really need to do for the long term."
Scientists Examine Artificial Gravity
By Leonard David
Senior Space Writer
SPACE.com
There is no doubt that future Red Planet explorers will be
more than a little weak-in-the-knees after a round-trip jaunt lasting
some three years.
Research shows that exposure to microgravity weakens muscle,
causes bone loss and plays havoc with a person's balance and
coordination.
But a team of scientists and engineers here at the
Massachusetts Institute of Technology's (MIT) Man-Vehicle Laboratory
are tackling the problem with experiments in artificial gravity.
Big wheel, keep on turning
Artificial gravity has long been viewed as the most effective
way to prevent deconditioning of space travelers.
In the 1950's, for example, space visionary Wernher von Braun
saw a huge, rotating space station to keep occupants fit and
functional. So too did moviemaker Stanley Kubrick and writer Arthur
Clarke in the two-thumbs-up sci-fi epic, 2001: A Space Odyssey.
But now there's a new spin on creating artificial gravity.
"There's the growing notion that we must get away from a large
and expensive-to-build spinning wheel and get down to something
considerably smaller," said MIT's Laurence Young, professor of
aeronautics and astronautics.
Young and his colleagues are hard at work on investigating use
of a personal centrifuge. Just a few yards (meters) in radius, the
device is too small to live in.
Yet an astronaut could get something akin to a gravitational
massage using the scheme.
"I call it a spin in the gym," Young told SPACE.com. "You go
into such a device for a workout, just like you go to the gym," he
said.
Questions still remain, Young admits. What gravity level is
best and along what axis of the body should g-force exposure be
applied? What is the minimum radius centrifuge you can get away with?
How much of a g-force is needed and for what duration in time?
"We don't have a great many answers now. But we know what some
of the questions are," Young said.
G-wizards
MIT Man-Vehicle Laboratory researchers feel they are on the
right track, and a rotating one at that.
"My personal view is that artificial gravity is the only
countermeasure that can remove the cause for space deconditioning. The
countermeasure pill has not yet been invented, and I believe it never
will be," said Heiko Hecht, a post-doctoral researcher at the lab.
Hecht said that it would be delusional to believe humans can
travel to Mars and return in good health without an effective way to
combat the adverse effects of prolonged weightlessness.
Studies are now underway to find out whether short-radius
intermittent spins in a centrifuge will do the trick, Hecht said.
Perhaps one to two hours a day of spinning, combined with exercise,
might be the answer, he said.
However, there are side effects in using short-radius devices,
said Kathleen Sienko, a Ph.D. student at MIT in health sciences and
technology.
"We want to show that it's worthwhile looking at artificial
gravity as a universal countermeasure," Sienko said. But there are key
issues needing more work, she said.
For instance, how best to combat sensory illusions and motion
sickness due to repeated changes between a person's state of
weightlessness and a state of artificial gravity.
Revolutionaries
To help sort out answers, volunteers have been put on a spin-
cycle at the MIT lab.
For some student subjects, a little centrifuge time looks good
on the resume, particularly if your career goal is becoming an
astronaut, said Lisette Lyne, a Ph.D. student at the lab.
At a flat rate of $10 per hour, carefully screened subjects
are strapped flat to a 6.6-foot (2-meter) radius rotating bed. A
canopy is placed over the individual, who is also outfitted with
instrumented headgear.
On the centrifuge, a person's head is placed at the center of
rotation, while the feet are at the rim. The centrifuge spins at 23
revolutions per minute, creating a one-gravity force at the feet of a
5-foot, 5-inch (1.7-meter) tall person.
Sienko said a range of responses have been measured.
An objective of the work, both Sienko and Lyne said, is to
show whether or not astronauts can maintain a dual adaptation. That
is, can they easily move between doing daily "free-floating" duties to
the countermeasure of a rotating environment?
Moreover, researchers said, can space travelers move back and
forth between these conditions without symptoms of illusory self-
motion or motion sickness?
World of trouble
Lyne said there is another major issue.
As far as a trip to Mars goes, no medical care will be waiting
to meet and greet astronauts touching down on the Red Planet. If the
vestibular system is impaired or compromised, a resulting fall due to
unbalance could result in a bone fracture, a completely broken bone,
or even death, she said.
"If you don't provide gravity on the way and maintain your
cardiovascular system, maintain healthy bones, and keep up your
calcium, you could be in a world of trouble. There are no hospitals.
You're on your own in a very remote place," Lyne said.
Professor Young said that moving artificial gravity
experiments into space is paramount. "We're going to have to get some
experience with spinning humans in space," he said.
NASA will consider carrying a short-radius centrifuge on a
future shuttle mission, Young said. Furthermore, new work on
artificial gravity is being supported through the National Space
Biomedical Research Institute in Houston, Texas, he said.
Young stresses that artificial gravity is one of several
innovative ideas being pursued. But the countermeasures now in
effective use for short-duration space missions "are inadequate Band-
Aids" for long haul crews headed for Mars, he said.
"We have to get off dead center where we've been for almost 20
years," Young said.
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 14 Ariane 5 launch of the PAS-1R communications satellite
from Kourou, French Guiana at 8:07 pm EST (0107 UT
November 15)
http://www.coola.com/cgi-bin/addinfo.cgi?pid=10003&rid=972904568&type=D
November 15 Soyuz launch of a Progress cargo spacecraft for the
International Space Station from Baikonur, Kazakhstan
at 8:32 pm EDT (0032 UT Nov. 16)
http://www.coola.com/cgi-bin/addinfo.cgi?pid=10003&rid=972904632&type=D
November 18 Delta 2 launch of the Earth Observing 1 and SAC-C
science satellites from Vandenberg Air Force Base,
California at 1:27 pm EST (1827 UT).
http://www.coola.com/cgi-bin/addinfo.cgi?pid=10003&rid=973486398&type=D
November 20 Ariane 4 launch of the Anik F1 communications
satellite from Kourou, French Guiana.
http://www.coola.com/cgi-bin/addinfo.cgi?pid=10003&rid=974072657&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
Other News
Black Holes, Jets, and Galactic Bubbles: Astronomers using the
Chandra X-Ray Observatory have imaged what appears to be a galactic
tug-of-war between a powerful black hole and an expanding bubble of
hot gas surrounding the distant galaxy Cygnus A. Jets of material
emanating from an accretion disk surrounding a black hole at the
galaxy's center extend outward 300,000 light-years to the bubble of
gas surrounding the galaxy. The jets heat up the bubble and cause it
to expand, even as the galaxy's powerful gravity tries to pull the gas
back in. The Chandra images, along with previous radio observations
of the galaxy, will allow astronomers to determine the strength of the
galaxy's magnetic field.
Cassini Continues Jupiter Imaging: Scientists have released more
images of Jupiter taken by NASA's Cassini spacecraft as it approaches
the giant planet en route to Saturn. The latest images, taken October
22 and 23 and released last Monday, are a series that encompass a full
10-hour Jovian day. Cassini will fly by Jupiter on December 30 no a
gravity-assist maneuver that will help send the spacecraft to Saturn,
where it will enter orbit in July 2004.
Nearby Neutron Star: Astronomers announced last week the discovery of
a fast-moving neutron star that is the closest-known such object to
the Earth. RX J185635-3754, as the neutron star is known, is 200
light-years from the Earth and moving at over 100 kilometers per
second (62 miles per second) on a trajectory that will bring it to
within 170 light-years of the Earth in 300,000 years. The object was
originally discovered in 1992 and confirmed to be a neutron star four
years later, but its position and velocity were only recently
confirmed, using data from the Hubble Space Telescope. The star is of
some scientific interest because it is isolated and is still quite
young.
Hot Young Stars: Astronomers said last week that they have discovered
a group of stars in a well-known star formation region that are
extremely hot. Using data from the Chandra X-Ray Observatory,
scientists found some massive young stars in the Orion Nebula to be as
hot as 60 million degrees Celsius (108 million Fahrenheit), more than
twice as hot as the previous record for massive stars. Astronomers
don't know why the stars are so hot, but have speculated that
interactions with protoplanetary disks or magnetic fields could cause
the high temperatures.
Briefly: While some pro-space candidates, like Florida Senator-elect
Bill Nelson, had success on Tuesday, others did not. Notable among
the losers was Jerry Doyle, a Republican who lost by more than a two-
to-one margin to Democratic incumbent Brad Sherman in California's
24th Congressional District, which spans portions of Los Angeles and
Ventura counties. An actor best known for his role as security chief
Michael Garibaldi on the science-fiction TV series "Babylon 5", Doyle
was a strong supporter of pro-commercial space policies, such as "Zero
G, Zero Tax" legislation... It's unlikely that the movie "Red
Planet", released in theaters in North America on Friday, will do much
to advance the cause of human exploration of Mars. The movie has been
panned by critics and earned a mere $9 million at the box office over
the weekend, good enough for only fifth place, far behind such
cinematic classics as "Charlie's Angels" and "Little Nicky". This
movie, combined with "Mission to Mars" eight months earlier, led a USA
Today reviewer to conclude, "Now we know why Mars is red. It's
embarrassed by how the movies have been sullying its reputation."
*** Articles ***
Humans On Mars: NASA on the Defensive
By Leonard David
Senior Space Writer
and Andrew Bridges
Pasadena Bureau Chief
SPACE.com
Humans are landing on Mars all the time in Hollywood movies,
with even more scheduled to do so this month.
But when will astronauts really go to Mars?
To hear NASA Administrator Daniel Goldin tell it, really soon.
"We're going to be in space forever with people first circling
this globe, and then we're going on to Mars, back to the Moon, and [on
to] bases on asteroids," Goldin said Tuesday, on the occasion of the
launch of the first full-time crew to the International Space Station.
Robots, not astronauts
But NASA's latest plans to explore Mars, unveiled just last
week, tell a different story.
"This program is not driven by human exploration," said Ed
Weiler, NASA's associate administrator for space science, in
presenting the American space agency's next decade of Martian
explorers -- 100-percent robotic, the lot of them.
The revised plan, prompted by the loss of a $300 million pair
of probes last year, left pro-human exploration backers disappointed.
Poor man's Mars
"This is a poor man's Mars program. We are not a poor country.
We can do a lot better than this," said Robert Zubrin, president of
the Mars Society, based in Indian Hills, Colorado. A strident
proponent of a humans-on-Mars initiative, Zubrin called the robotic
missions fine -- "but they don't go far enough."
"If we're serious about doing science on Mars, let alone
settlement, we have to send people," Zubrin said. "This plan does not
take any significant steps in that direction."
Louis Friedman, executive director of The Planetary Society,
the Pasadena, California-based space exploration advocacy group,
echoed Zubrin's criticism, saying the revised program showed no
connection to either human missions or even a permanent robotic
presence on Mars.
"That's clearly absent, no one mentions it and the sequence
does not allow for that," Friedman said. "It's not taking the program
to its logical conclusion."
Paving the way
NASA has kicked around the idea of astronauts strutting about
on Mars for decades, at times more seriously than at others. A 1989
study, prepared for President Bush, pegged the cost of such a multi-
year mission at nearly half a trillion dollars, promptly cooling
enthusiasm for the idea.
But NASA-supported scientists, under the aegis of its Human
Exploration and Development of Space (HEDS) enterprise, have been
plugging away on a suite of instruments that would enable a crewed
mission to travel to Mars and live there safely for an extended period
of time.
Scott Hubbard, NASA's Mars program director, said the HEDS
payloads and other technologies, including the ability to land a
spacecraft on Mars with pinpoint precision, would help get humans to
Mars.
"I feel like we do pave the way," Hubbard said of the revised
Mars plan. "All of this leads up to it. It's maybe more connected than
[Friedman] realizes."
HEDS down, for now
The various HEDS instruments, originally slated to travel in
batches to Mars in 2001 and 2003, would do everything from produce
breathable oxygen from the thin, carbon dioxide-rich Martian
atmosphere to assess the potential threat of dust and radiation to
astronauts on the planet's surface.
However, the 2001 lander mission was scrapped and in 2003 NASA
elected to send a twin-rover mission that will not include the HEDS
payloads. That means most will have to wait until 2007 to hitch a ride
to Mars. (The 2001 orbiter will carry one of the original HEDS
payloads.)
"We're enthusiastic about the chance to redefine our
instruments, but seven years is a long time to wait to see them on
Mars," said Peter Smith, a planetary scientist at the University of
Arizona's Lunar and Planetary Laboratory. Smith had hoped his
experiment, designed to measure dust devils, would travel to the Red
Planet in 2003.
Show Mars the money
The wait to see humans on Mars will take even longer. Nor will
NASA have to grapple with just technology and science to do so --
funding may represent an even bigger hurdle.
"To make a commitment to humans on Mars is something that the
administration and Congress would have to do," NASA's Hubbard said.
Former Congressman Robert Walker, who once headed the powerful
space and aeronautics subcommittee in the House of Representatives,
said don't look to Congress to shell out the dough required to plop
people on Mars.
"I don't think I would want to look at any scheme that
depended upon Congress to get me the money. You won't find Congress
receptive to $20 billion, $30 billion, whatever the figure is," said
Walker, speaking at a space tourism workshop last June.
Rather, Walker -- a science and technology advisor on Gov.
George W. Bush's presidential bid -- said a humans-to-Mars enterprise
needs a little Red Planet politics in the private sector. Firms
involved in carrying out such a Mars project could receive tax-breaks
to spark interest, he said.
"How interested would Microsoft or General Motors become if
they were told, 'If you sponsor a trip to the Moon or a mission to
Mars, the government will give you 50 years of tax-free status for the
entire company?' They would go subcontracting out with all the people
that NASA now subcontracts with in order to do those missions," Walker
said.
Mining Space: Whither NASA?
By Leonard David
Senior Space Writer
SPACE.com
While the "pickings" might be good for mining the Moon or
crushing up asteroids, creating markets and making money on the space
frontier currently is more prophet than profit.
NASA may be the linchpin in the equation that describes the
mining of space resources, said some international space experts who
met this week at the Colorado School of Mines for a Space Resources
Round Table. Participants are taking a short-term and far-future look
at utilizing the abundance of available space resources scattered
throughout the solar system.
NASA is on the cusp of introducing a new strategy for
supporting human space exploration, said John Mankins of NASA's
advanced projects office.
The agency is readying a 21st-century step-by-step plan to
first push human crews to special locales far from Earth tagged
libration points, then initial missions to the Moon, Mars and
asteroids, Mankins said.
"First we will go into Earth's neighborhood, then
interplanetary, and then, eventually, for sustained presence in
locations such as Mars," Mankins said.
The hope is to find common ground between a space agency wish
list of human exploration projects and initiatives that foster the
commercial development of space, Mankins said.
The strategy is to unfold over the next five to 10 years,
Mankins said. "Some might be disappointed with the pace, but it's a
way of getting off zero," he told the workshop audience.
Mankins said the strategy includes new monies to spur
"technology for human exploration and development of space" -- or
THREADS for short.
Step-by-step
NASA's roster of technology needs, said Mankins, centers on
six themes: Space resources development; space utilities and power;
habitation and bioastronautics; space assembly, inspection and
maintenance; exploration and expeditions; and space transportation.
While encouraged about the NASA plan, Jim Blacic, research
scientist at Los Alamos National Laboratory in New Mexico, said that
the country has moved little over the years in terms of space-resource
utilization.
"We're more or less treading water. The main problem is that
we don't have a market," Blacic said.
"We need the primary customer, NASA, to step up and create a
demand for the product. Commercial customers will follow. However, the
key roadblock, as always, is the high cost of space transportation,
especially Earth to low Earth orbit," Blacic said.
History in the making
Moving into space mimics the forces that shaped historic
mining frontiers -- that is, going into a wilderness to exploit
resources, said Dale Gray of Frontier Historical Consultants in Grand
View, Idaho.
His research has found that there is a direct link between the
speed of frontier development and the height of the "launch bar" --
the amount of money needed to reach the moment a first product is
sold.
"The higher the bar, the slower the frontier will develop,"
Gray said.
"Currently, space is a transportation frontier. It is similar
in many respects to historic ocean-crossing or transcontinental
transportation frontiers. To my knowledge, no frontier transportation
system has ever come on line, on budget, and on time," Gray said.
But as transportation costs drop, space will become a source
of resources needed on Earth. "Ultimately, there is no way to predict
what 慿iller application' will pull our civilization off the face of
the Earth and into orbit," Gray said.
People payloads
Markets have replaced governments as the engines of
technological change throughout the world, said Gregg Maryniak,
executive director of the X Prize Foundation in St. Louis, Missouri.
The X Prize is a competition between worldwide teams vying for
a prospective $10 million purse in the hopes of kick starting
suborbital space tourism.
Maryniak said that space planes that routinely rocket back and
forth from Earth orbit, like airline traffic of the day, will likely
happen in the future. "But to have airline-like space operations, you
need airline-like payloads, which is people," he said.
Some 500 men and women have now traveled into space, with
surveys showing a large and eager public ready to follow. More
importantly, they appear ready to plunk down cold cash for a space-
travel ticket.
First, tens of people, then hundreds, followed by thousands of
individuals are expected to cruise the orbital highways, Maryniak
said.
Over time, space hotels and habitats will dot near-Earth
space. This, in turn, will create a market niche for life-support
products, radiation shielding, as well as artificial gravity, Maryniak
said. Space resources can be supplied on an economic basis to spur and
maintain this space-tourism market, he said.
Lure of lunar ice
Space resource experts continue to be intrigued by the
prospect that water is stashed at the Moon's poles.
Tucked away in craters that never see sunlight, water would
have been primarily brought to the lunar surface via impacting comets.
If there, water could be processed to yield both rocket fuel and
oxygen. That would be a resource bonanza, workshop participants said,
ideal for supporting future Moon bases and other human space
exploration goals.
NASA's Lunar Prospector spacecraft that orbited the Moon in
1998-99 did spot rich fields of hydrogen. While some scientists infer
from the probe's data that water had been detected, others contend
that Lunar Prospector measured deposits of hydrogen implanted there by
blasts of solar wind washing across the Moon's crater pocked face.
"The question of what's at the permanently shadowed craters on
the Moon is of great interest," said Gerald Sanders, a space resources
expert at the NASA Johnson Space Center in Houston, Texas. "Is it
hydrogen, or water, a combination, or something else? That one answer
could totally shape how we progress going back to the Moon," he said.
Tons of water
"I suspect that we have found water ice," said Alan Binder,
director of the Lunar Research Institute in Tucson, Arizona. He was
Lunar Prospector's principal investigator.
Lunar Prospector found numbers of "cold traps," Binder said.
These are small expanses of lunar surface that he believes hold water-
ice crystals mixed in with surface materials. "What we are probably
seeing in the data is water ice," he said.
Binder told SPACE.com that he estimates on the order of 300
million metric tons of water is available on the Moon. But more
knowledge is needed about where and how large permanently shadowed
regions are, he said, as are lunar landers to conduct up-close-and-
personal look-sees into those resource-laden spots.
A strong proponent for a commercial return to the Moon, Binder
said that the low-cost Lunar Prospector -- about a quarter the cost of
other space-exploring probes like it -- produced a high scientific
return, opening the doors for private lunar ventures and showing NASA
it can be done for much less.
"To wait for NASA to get us back to the Moon is futile,"
Binder said.
========
This has been the November 13, 2000, issue of SpaceViews.
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