CAPE CANAVERAL, Fla. (AP) — The world's biggest extraterrestrial
explorer, NASA's Curiosity rover, rocketed toward Mars on Saturday on a search
for evidence that the red planet might once have been home to itsy-bitsy life.
It will take 8½ months for Curiosity to reach Mars following a journey of 354
million miles.
An unmanned Atlas V rocket hoisted the rover, officially known as Mars Science
Laboratory, into a cloudy late morning sky. A Mars frenzy gripped the launch
site, with more than 13,000 guests jamming the space center for NASA's first
launch to Earth's next-door neighbor in four years, and the first send-off of a
Martian rover in eight years.
NASA astrobiologist Pan Conrad, whose carbon compound-seeking instrument is on
the rover, had a shirt custom made for the occasion. Her bright blue,
short-sleeve blouse was emblazoned with rockets, planets and the words, "Next
stop Mars!"
Conrad jumped, cheered and snapped pictures as the rocket blasted off a few
miles away. So did Los Alamos National Laboratory's Roger Wiens, a planetary
scientist in charge of Curiosity's rock-zapping laser machine, called ChemCam.
Wiens shouted "Go, Go, Go!" as the rocket soared. "It was beautiful," he later
observed, just as NASA declared the launch a full success.
The 1-ton Curiosity — as large as a car — is a mobile, nuclear-powered
laboratory holding 10 science instruments that will sample Martian soil and
rocks, and analyze them right on the spot. There's a drill as well as the
laser-zapping device.
It's "really a rover on steroids," said NASA's Colleen Hartman, assistant
associate administrator for science. "It's an order of magnitude more capable
than anything we have ever launched to any planet in the solar system."
The primary goal of the $2.5 billion mission is to see whether cold, dry, barren
Mars might have been hospitable for microbial life once upon a time — or might
even still be conducive to life now. No actual life detectors are on board;
rather, the instruments will hunt for organic compounds.
Curiosity's 7-foot arm has a jackhammer on the end to drill into the Martian red
rock, and the 7-foot mast on the rover is topped with high-definition and laser
cameras. No previous Martian rover has been so sophisticated or capable.
With Mars the ultimate goal for astronauts, NASA also will use Curiosity to
measure radiation at the red planet. The rover also has a weather station on
board that will provide temperature, wind and humidity readings; a computer
software app with daily weather updates is planned.
The world has launched more than three dozen missions to the ever-alluring Mars,
which is more like Earth than the other solar-system planets. Yet fewer than
half those quests have succeeded.
Just two weeks ago, a Russian spacecraft ended up stuck in orbit around Earth,
rather than en route to the Martian moon Phobos.
"Mars really is the Bermuda Triangle of the solar system," Hartman said. "It's
the death planet, and the United States of America is the only nation in the
world that has ever landed and driven robotic explorers on the surface of Mars,
and now we're set to do it again."
Curiosity's arrival next August will be particularly hair-raising.
In a spacecraft first, the rover will be lowered onto the Martian surface via a
jet pack and tether system similar to the sky cranes used to lower heavy
equipment into remote areas on Earth.
Curiosity is too heavy to use air bags like its much smaller predecessors,
Spirit and Opportunity, did in 2004. Besides, this new way should provide for a
more accurate landing.
Astronauts will need to make similarly precise landings on Mars one day.
Curiosity will spend a minimum of two years roaming around Gale Crater, chosen
as the landing site because it's rich in minerals. Scientists said if there is
any place on Mars that might have been ripe for life, it would be there.
"I like to say it's extraterrestrial real estate appraisal," Conrad said with a
chuckle earlier in the week.
The rover — 10 feet long and 9 feet wide — should be able to go farther and work
harder than any previous Mars explorer because of its power source: 10.6 pounds
of radioactive plutonium. The nuclear generator was encased in several
protective layers in case of a launch accident.
NASA expects to put at least 12 miles on the odometer, once the rover sets down
on the Martian surface.
This is the third astronomical mission to be launched from Cape Canaveral by
NASA since the retirement of the venerable space shuttle fleet this summer. The
Juno probe is en route to Jupiter, and twin spacecraft named Grail will arrive
at Earth's moon on New Year's Eve and Day.
Of that, planetary scientists are certain, which leaves them puzzling over what
could be producing methane gas detected in the thin Martian air. Methane
molecules are easily blown apart by ultraviolet light from the Sun, so any
methane floating around must have been released recently.
Could the gas be burbling from something alive? Cows, after all, burp methane on
Earth. Other creatures, including a class of micro-organisms that live without
oxygen, also produce methane.
NASA could get some answers soon. On the launching pad at Cape Canaveral in
Florida is a spacecraft, the Mars Science Laboratory, which is scheduled to lift
off on Saturday and plop down on Mars next August. It will deliver an
S.U.V.-size rover named Curiosity that carries an instrument that can detect
methane in the air, and if it does, it will unleash a new wave of excitement
about the prospect of life on Mars.
“Based on evidence, what we do have is, unequivocally, the conditions for the
emergence of life were present on Mars — period, end of story,” said Michael J.
Mumma, a senior scientist for NASA at the Goddard Space Flight Center in
Greenbelt, Md., who led one of three teams that have made still-controversial
claims of detecting methane in Mars’ atmosphere. “So life certainly could have
arisen there.”
Because Mars is smaller than Earth, it cooled faster, and it probably would have
been hospitable for life earlier. That raises the intriguing possibility that
pieces of Mars containing microbes were blasted into space by asteroid impacts
and later landed on Earth, seeding life here.
In other words: We could all be descendants of Martians.
The possibility of Martians has long fueled the imagination of Earthlings, from
the Edgar Rice Burroughs Barsoom fantasy novels to the canals Percival Lowell
deluded himself into seeing through his telescope to Orson Welles’s “War of the
Worlds” radio play.
Other times, the pendulum swung back the other way. Mariner 4, the first space
probe to whiz past Mars, in 1965, sent back pictures not of verdant forests, but
of barren rocks. And NASA’s two Viking landers in 1976, equipped with
sophisticated life chemistry experiments, analyzed the soil and found it devoid
of the organic building blocks of life.
Mars, it appeared in 1976, was really most sincerely dead.
“Things looked so grim for exobiology on Mars,” said Christopher F. Chyba, a
professor of astrophysical sciences at Princeton University. “We made this
tremendous investment in two Viking landers. There was a backlash of the people
who felt the biology was oversold and premature.”
NASA subsequently played down the notion of life on Mars and instead set out on
a methodical campaign to explore the past geology and climate of Mars. Although
Mars today looks dry and cold — dead — geological markings like gullies, dry
lake beds and colossal canyons point to a liquid past. “Follow the water” became
the mantra. NASA’s last two rovers, Spirit and Opportunity, found convincing
evidence of environments that were habitable in the distant past. Curiosity will
go further, looking for carbon-based molecules, including methane, that are the
building blocks of life.
Recent orbital images show that water might still occasionally flow on the
surface of Mars. New knowledge about life on Earth and how it can thrive in
seemingly hostile environments like the dark, boiling waters near ocean-bottom
volcanic vents also made scientists less dismissive of the notion that life
persists on Mars. In 1996, a team of NASA scientists announced they had found
fossilized microbes in a Martian meteorite that had landed in Antarctica. Those
claims remain at least as controversial as the methane findings.
But short of photographing a cow or some other critter ambling among the rocks,
Curiosity is not going to discover life. As with every NASA probe since the
Viking landers, Curiosity is not carrying experiments designed to tell whether
the building blocks of life ever came together to form life. If there are
microbial Martians thriving in the soil, Curiosity will not see them.
“I don’t think we’ve put down enough groundwork,” said Michael A. Meyer, NASA’s
lead scientist for Mars.
That is frustrating in particular for Gilbert V. Levin, who believes his
experiment on the Vikings 25 years ago, designed to detect life, did indeed
detect life.
Drops of a nutrient solution containing radioactive carbon-14 were added to
Martian soil, and a stream of radioactive carbon dioxide was detected rising out
of the soil. That is what would be expected from micro-organisms eating the
food.
To rule out the possibility that a nonbiological chemical process was generating
the carbon dioxide, other samples were heated to 320 degrees Fahrenheit to
sterilize them. No radioactive carbon dioxide was seen rising from those when
the nutrient drops were added, fitting with the hypothesis that the heat had
killed the Martian microbes. If a nonbiological process were at play, the
radioactive carbon dioxide should have been seen after the sterilization as
well.
But other Viking experiments had failed to measure any organic molecules, so Dr.
Levin’s results — even though they matched exactly what would be expected for
life — were like announcing the discovery of a brick house in the absence of
bricks. The consensus was that the claim was mistaken.
A recent discovery, however, offers a possible explanation for how Dr. Levin
could be right after all. In 2008, NASA’s Phoenix lander found chemicals known
as perchlorates in the Martian soil. Viking’s organic molecule detector heated
the soil to release organics. But heating organic molecules in the presence of
perchlorates destroys them, so even if they were there, Viking’s experiment may
have inadvertently missed them.
Dr. Levin said a more sophisticated version of his experiment, weighing a couple
of pounds and costing a few million dollars, could definitively validate or
disprove the Viking results.
“But they won’t fly it,” Dr. Levin said. “Changing a paradigm is a tough thing.
We’ve run this experiment thousands of times on Earth. It’s never given a false
positive. It’s never given a false negative.”
The two missions that are to follow Curiosity — collaborations between NASA and
the European Space Agency — do not have a version of Dr. Levin’s experiment
planned. Christopher E. Carr, a research scientist at the Massachusetts
Institute of Technology intrigued by the possibility that life on Earth could
have started on Mars, has proposed an even more ambitious experiment: Send a DNA
sequencer to Mars. That, too, has yet to find a mission to fly on.
Definitive answers may have to wait until a mission that brings Mars rocks back
to Earth for study.
But that may be a very long wait. The Obama administration, mindful of tight
federal budgets, has yet to give the green light on the 2016 and 2018 missions
and is considering canceling them. Curiosity may be the last spacecraft landing
on Mars for many years.
“That would derail the whole search for life, either extinct or extant, on
Mars,” Dr. Mumma said. “That would be a disaster.”
November
11, 2008
The New York Times
By KENNETH CHANG
The Phoenix
Mars lander is dead.
Mission managers said Monday that they had not heard from the NASA spacecraft
for a week and that they thought it had probably fallen quiet for good.
“At this time, we’re pretty convinced that the vehicle is no longer available
for us to use,” said Barry Goldstein, the project manager. “We’re actually
ceasing operations, declaring an end to mission operations at this point.”
With the onset of winter and declining power generated by the Phoenix’s solar
panels, managers knew the lander would succumb soon, but had hoped to squeeze
out a few more weeks of weather data.
But on Oct. 27, just after Phoenix finished its last major experiment analyzing
Martian soil, an unexpected dust storm hit. The batteries, already low from
running the experiment, ran out of energy.
The spacecraft first put itself into a low-energy “safe mode,” then fell silent.
It revived itself on Oct. 30, but, with the dust still swirling, was never able
to fully recharge its batteries. Each day, the solar panels would generate
enough electricity for the spacecraft to wake up, but then the batteries drained
again.
The last communication came on Nov. 2. Mr. Goldstein said the orbiting
spacecraft would continue to listen for a few more weeks on the faint chance
that the Phoenix defies their expectations.
The Phoenix landed in May to examine the northern arctic plains, and the $428
million mission, originally scheduled to last three months, was extended twice
“I’m just thrilled to death what we’ve been able to do here,” said Peter H.
Smith of the University of Arizona, the mission’s principal investigator. The
spacecraft accomplished all of its main objectives, but some science remained
unfinished. The Martian soil proved to be extremely clumpy, and the spacecraft
had recurrent trouble getting the samples through gratings into the spacecraft’s
laboratory apparatus.
Dr. Smith admitted disappointment that a sample from one of the trenches that
the Phoenix had dug was never successfully analyzed. “We got it all the way up
to the instrument and even tried pressing it down,” Dr. Smith said. “But it
wouldn’t go in.”
But Dr. Smith highlighted what the Phoenix did discover. It confirmed a layer of
ice not far below the surface. It found some carbonates and clays, which suggest
that liquid water may have be present within the past few millennia. It found
the arctic soil to be alkaline, not acidic as has been observed in other parts
of Mars. It also discovered perchlorates, a class of chemicals that in high
concentrations can be toxic to life, but which can also serve as a food source
for some microbes.The spacecraft took 25,000 photographs, including panoramas of
the landing and microscopic images of dust particles.
“It’s really an Irish wake, not a funeral that we’re looking forward to,” said
Douglas McCuiston, director of the Mars Exploration Program at NASA
headquarters. “NASA got what it wanted out of this mission.”
The data may yet reveal the presence of carbon-based molecules that could be
building blocks for life, Dr. Smith said, and that the region might, at least
occasionally, be suitable for life. The Phoenix was not designed to look
directly for signs of life. Dr. Smith said the scientists had begun writing the
scientific articles describing their findings.
In the coming months, when sunlight disappears entirely in the northern plains,
temperatures will fall to minus-240 to minus-300 degrees Fahrenheit, and the
Phoenix will become encased within carbon dioxide ice. When spring returns, NASA
plans to try reviving the Phoenix again, but the expectation is that the
spacecraft’s electronics will not survive the long, deep freeze.
WASHINGTON
(Reuters) - Scientists working on NASA's Phoenix Mars Lander mission are
reporting what they call compelling evidence that the robot craft has found ice
while digging on the Martian surface.
NASA is expected to give details on the discovery during a news conference on
Friday.
The small science probe landed safely last month on a frozen desert at the
Martian north pole to search for water and assess conditions for sustaining
life.
Small chunks of bright material described as the size of dice have disappeared
from inside a trench where they were photographed by the craft earlier this
week, NASA said in a statement late on Thursday.
This has convinced scientists the chunks were ice -- frozen water -- that
vaporized after digging exposed it, NASA said.
"It must be ice," said mission principal investigator Peter Smith of the
University of Arizona. "These little clumps completely disappearing over the
course of a few days. That is perfect evidence that it's ice. There had been
some question whether the bright material was salt. Salt can't do that."
The presence of water on Mars is a hot topic for scientists. They have presented
strong evidence in recent years of huge deposits of frozen water at the Martian
poles and point to geological features that indicate that large bodies of water
have flowed on the planet's surface in the distant past.
Water is a key to the question of whether life, even in the form of mere
microbes, has ever existed on Mars. On Earth, water is a necessary ingredient
for life.
The chunks were left at the bottom of a trench dubbed "Dodo-Goldilocks" when
Phoenix's robotic arm enlarged that trench on June 15. Several chunks were gone
when Phoenix looked at the trench again on Thursday, NASA said.
The U.S. space agency also said that the lander, digging in a different trench,
used its robotic arm to connect with a hard surface that has scientists
believing they have found an icy layer on the Martian surface.
The $420 million lander spent 10 months journeying from Earth to Mars.
February
21, 2008
The New York Times
By KENNETH CHANG
To figure
out an odd landscape feature on Mars, play in a big sandbox.
Enlist some high school students, too.
That’s what some scientists at the Utrecht University in the Netherlands did,
and they believe they now know how sediment deposits spilling out of the mouth
of some water channels on Mars were shaped in a series of terraces that look
like terraced rice paddies.
But no similar natural formations have been seen in river deltas on Earth.
Usually river sediments spill out in a smooth, sloping fan like the Mississippi
delta.
Planetary geologists have been speculating about the terraced fans since they
were first spotted by NASA’s Mars Global Surveyor eight years ago. About 10
stepped fans have been identified, most at the base of a steep slope emptying
into a basin like an impact crater. (Most of the 200 sediment fans seen on Mars
do not have the stepped structure. Another mystery is why many of the river
channels seem to have no sediment deposit at all.)
Some scientists suggested the terraced fans were the result of repeated shore
erosion as a lake in the basin dried up. Others thought repeated landslides
might have formed the steps.
The sandbox experiment, reported in Thursday’s issue of the journal Nature,
supports a third notion. The terraces form by the interaction of the sediment
flow with the water’s edge, which is rising as the basin fills.
“Where that’s happening, you’re getting a little lip,” said Erin R. Kraal, the
lead author of the Nature paper. Pulses of flow and sediment produced multiple
terraces. “They’re just stacking one atop the other,” she said.
While a postdoctoral researcher at Utrecht, Dr. Kraal became intrigued by the
terraced fans and mentioned them to her colleagues there. Utrecht has a set-up
known as Eurotank, essentially a 16- by 40-foot sandbox for studying sedimentary
dynamics.
High school students visiting the laboratory as part of an educational project
saw the Mars pictures on the laboratory walls and were interested in helping on
an experiment, which eventually turned into a short educational movie about the
Martian fans.
The students dug a crater in the sandbox and shaped a water channel. Then they
sent water down the channel — and the result was a terraced fan, just as on
Mars.
“We didn’t expect it to be so successful the first time,” said Dr. Kraal, now a
research scientist at Virginia Polytechnic Institute. “We were really surprised
they formed so quickly and so easily.”
Dr. Kraal and her colleagues, Maurits van Dijk, George Postma and Maarten G.
Kleinhans later repeated the experiments more rigorously so they could correlate
their sandbox results with the Martian terrain.
They estimate that the water necessary to form one of the Martian fans, which
measure up to a dozen miles wide, would equal 10 years of Mississippi River
flow. The whole structure appears to have formed in one event lasting perhaps
tens of years, they said.
“It does look like she’s experimentally shown here that this type of deposit can
form in a single event type of discharge,” said Rossman P. Irwin III, a
geologist at the Smithsonian Institute’s Center for Earth and Planetary Studies
who has also studied the terraced fans. “It offers some good experimental
support for a type of feature that is basically unique to Mars and really was
not well understood.”
December
12, 2007
The New York Times
By KENNETH CHANG
SAN
FRANCISCO — The lame wheel on the NASA Mars rover Spirit has proved an
invaluable science tool, turning up evidence of a once habitable environment,
scientists said Monday.
Meanwhile, images from the Mars Reconnaissance Orbiter have largely unraveled
the mystery of geological patterns called “spiders” that appear each spring
around the south pole.
The scientists reported their findings here at a meeting of the American
Geophysical Union.
The right front wheel of Spirit stopped turning in March 2006. Since then, the
rover has been driving backwards, dragging the lame wheel along. This May,
scientists noticed a bright spot in the trail of overturned dirt.
They turned Spirit around for a closer look, finding high levels of silica, the
main ingredient of window glass. They then aimed the rover at a nearby rock,
wanting to break it apart to determine if the silica was just a surface coating,
or if the rock was silica all the way through.
The target rock survived Spirit’s charge, but a neighboring rock cracked open.
The interior of that rock, which the scientists informally named “Innocent
Bystander,” turned out to be rich in silica.
On Earth, such high concentrations of silica can form in only two places: a hot
spring, where the silica is dissolved away and deposited elsewhere, or a
fumarole, an environment, often near a volcano, where acidic steam rises through
cracks. The acids dissolve other minerals, leaving mostly silica. On Earth, both
environments teem with life.
Spirit’s twin, Opportunity, which has been exploring a spot on the other side of
Mars, has found evidence of an environment once steeped in acidic groundwater.
The silica discovery is the first time that Spirit has seen signs of widespread
water in its surroundings, a 90-mile-wide impact crater known as Gusev Crater.
Gusev was chosen as a landing site, because, at least from orbit, it looks as if
it were once a lake with what appears to be river channels flowing away from it.
However, until now, the rocks that Spirit has examined have largely been
volcanic basalt with little hint of water.
“This shows us a side of Mars we haven’t seen before, and my guess is that it’s
more common than we had thought,” said Steven W. Squyres, the project scientist
for the rovers. “Whichever of those conditions produced it, this concentration
of silica is probably the most significant discovery by Spirit for revealing a
habitable niche that existed on Mars in the past.”
From far above the surface, the Mars Reconnaissance Orbiter has been taking a
closer look at radial patterns of “spider” gullies, as well as bright and dark
fan-like features that appear in the Martian landscape each spring.
Scientists first spotted the gullies several years ago in images taken by the
Mars Global Surveyor. With the much higher resolution of Reconnaissance Orbiter,
scientists saw for the first time that the gullies were wider at the center of
the pattern. Another instrument allowed them to map the images onto the Martian
topography; the centers of the spiders were at the top of the small hills. Those
two bits of information indicated that the gullies were carved by something
flowing uphill — and that pointed to carbon dioxide.
At a news conference on Tuesday, Candice Hansen, deputy principal investigator
for the orbiter’s high-resolution camera, said it now appeared that a layer of
translucent carbon dioxide ice, perhaps half a yard thick, formed over the south
polar terrain during the winter months.
In the spring, sunlight warms the ground, vaporizing carbon dioxide at the base
of the ice layer. The gas flows uphill, carving channels in the underlying soil.
At weak points in the ice, the gas erupts in small geysers. The release of
pressure causes the carbon dioxide gas to freeze solid and fall as white snow —
the white parts of the fan-like patterns. Dust blown out with the carbon dioxide
falls on the ground to form the dark parts of the fans.
“It is unlike anything on Earth,” Dr. Hansen said, though similar patterns have
been seen on the Neptunian moon of Triton.
September 28, 2007
By THE ASSOCIATED PRESS
Filed at 1:00 a.m. ET
The New York Times
LOS ANGELES (AP) -- NASA's rover Opportunity has reached its first stop
inside a huge Martian crater and was poised Thursday to carry out the first
science experiments.
Ground controllers planned to send commands late in the day to the six-wheel
robot to examine bright rock layers arranged like a bathtub ring within Victoria
Crater. Results on how the rover fared were expected Friday, said John Callas,
the rover project manager at NASA's Jet Propulsion Laboratory in Pasadena.
Mission managers wanted to delay the science operations because of a power
outage at one of the international network of antennas that communicates with
interplanetary spacecraft. But they changed their minds after they secured
another antenna.
Opportunity rolled to the crater lip last month and began a calculated descent
down the inner wall toward a shiny band of bedrock that scientists believe may
be part of an ancient Martian surface. After a series of three drives, the rover
parked itself 40 feet below the rim at a 25-degree tilt -- the steepest angle it
has encountered since landing on the planet.
Opportunity's first task will be to use the tools on its robotic arm to touch
and drill into the rock slab. Mission scientists expect it to stay in place for
at least a week before scaling farther down the crater to sample other rocks.
''We're going to take our time collecting the data,'' principal investigator
Steve Squyres of Cornell University said in an e-mail. ''We invested way too
much effort in getting here to blow it by being hasty.''
Opportunity and its twin Spirit have outlasted their original, three-month
mission since parachuting to opposite sides of Mars in 2004. The solar-powered
rovers recently survived a raging dust storm that forced them to go into sleep
mode to conserve energy.
Spirit is currently exploring a plateau called Home Plate for evidence of
volcanism. Though Martian winter is still seven months away, mission managers
have started looking for a safe spot for Spirit to retreat to.
July 30, 2007
By THE ASSOCIATED PRESS
Filed at 2:10 p.m. ET
The New York Times
LOS ANGELES (AP) -- A three-legged NASA spacecraft with a long
arm for digging trenches is going to the Martian north pole to study if the
environment is favorable for primitive life.
But before it can start its work, the Phoenix Mars Lander must survive landing
on the surface of the rocky, dusty Red Planet, which has a reputation of
swallowing manmade probes. Of the 15 global attempts to land spacecraft on Mars,
only five have made it.
''Mars has the tendency to throw you curve balls,'' said Doug McCuistion, who
heads the Mars program at NASA headquarters.
Phoenix, which is pieced from old hardware that was shelved after two
embarrassing Mars failures in 1999, will blast off from Cape Canaveral, Fla.,
aboard a Delta II rocket on a 423-million-mile trip. The three-week launch
window opens Aug. 3.
Unlike the durable twin rovers near the equator, the Phoenix Mars Lander will
sit in one place and extend its long arm to dig trenches in the permafrost and
scoop up soil for analysis. Made of aluminum and titanium, the 8-foot-long arm
acts like a backhoe and can dig down 20 inches and rotate.
Although Phoenix lacks the tools to detect past or current life, scientists hope
it will shed light on whether the northern arctic possesses the signature
ingredients for microbes to exist.
The lander should arrive at Mars 10 months after it launches and touch down in
the northern plains for its three-month mission. If successful, it will be the
first time since the Viking missions three decades ago that a robot will drill
beneath the Martian surface.
Once it lands, Phoenix will heat the soil samples in miniature ovens to study
their chemistry. The lander can detect the presence of organics, although it
won't be able to tell if there's DNA or protein, said principal investigator
Peter Smith of the University of Arizona, Tucson.
The landing site was chosen because previous spacecraft found evidence that
frozen water lurked below the surface. Some believe the shallow valley measuring
about 30 miles wide might be the remnant of an ancient sea. However, Phoenix
will look for evidence of liquid water that may have existed as recently as
100,000 years ago.
There's no water on the arid Martian surface today, but Phoenix's job is to find
out whether the underground ice may have melted, creating a wetter environment.
Scientists generally agree that water, along with the presence of organic
materials and a stable heat source, is needed to support life.
To prevent Phoenix from accidentally bringing organisms to Mars, technicians had
to take special care while prepping the lander for launch. It underwent dry heat
treatment and precision cleaning to reduce the amount of germs on its surface.
Its trench-digging arm was also sealed in a special wrapping to prevent
contamination.
Phoenix is the first project from NASA's Scout program, a low-cost complement to
pricier Mars missions in orbit and on the surface. Managed by the Jet Propulsion
Laboratory in Pasadena, Phoenix cost $420 million compared to the hardy rovers
Spirit and Opportunity, which cost $820 million to launch in 2003.
True to its name, Phoenix rose from the ashes of previous missions. It was
supposed to fly in 2001 as a sidekick to the Mars Odyssey orbiter. The orbiter
reached Mars, but the lander mission was canceled in the wake of back-to-back
losses in 1999.
The Mars Climate Orbiter burned up as it neared Mars because Lockheed
Martin/NASA mismatched metric and English measurement units. The Mars Polar
Lander tumbled to its death after its rocket engine shut off prematurely as it
tried to touch down on the south pole. Neither wreckage has been found.
Phoenix, built by Lockheed Martin, carries several science instruments similar
to ones that flew on the ill-fated Polar Lander mission. Engineers rigorously
tested the spacecraft over the last four years ''to drive out any of the
problems we might have in the system,'' said Barry Goldstein, project manager at
JPL.
If Phoenix survives its primary mission, it will turn into a weather station and
collect data on the atmosphere.
July 5, 2007
Filed at 12:31 a.m. ET
By THE ASSOCIATED PRESS
The New York Times
PASADENA, Calif. (AP) -- A powerful dust storm on Mars has
worsened and is affecting the twin rovers' operations on the Red Planet, mission
scientists say.
The storm, which has been brewing for a week, has partially blocked the sun. The
rovers Spirit and Opportunity, which have solar panels, rely on sunlight to
charge their batteries.
Scientists maintain that the robots, which are used to operating at low power
levels, are not in danger.
''The storm is affecting both rovers and reducing the power levels on
Opportunity,'' project manager John Callas of NASA's Jet Propulsion Laboratory
said in a statement posted Tuesday on the space agency's Web site.
Solar array energy on Opportunity dropped from 765 watt-hours to 402 watt-hours
as dust levels increased over the past week. The rover scaled back operations on
June 30 to conserve energy.
The storm has already postponed Opportunity's descent into Victoria Crater to
learn more about the planet's geologic past. Scientists hoped to send the rover
into the crater this weekend, but unfavorable weather has delayed the entry
until at least July 13.
The regional storm is the worst to hit the rovers since they landed on opposite
ends of Mars in 2004, and scientists expect the storm to last for at least
another week.
The highest dust activity is centered near Opportunity. However, weather data
show the storm might have peaked, meaning the worst could be behind the rovers.
LOS ANGELES (AP) -- NASA's aging but durable Mars rover
Opportunity will make what could be a trip of no return into a deep impact
crater as it tries to peer further back than ever into the Red Planet's geologic
history.
The descent into Victoria Crater received the go-ahead because the potential
scientific returns are worth the risk that the solar-powered, six-wheel rover
might not be able to climb out, NASA officials and scientists said Thursday.
The vehicle has been roaming Mars for nearly 3 1/2 Earth years. Scientists and
engineers want to send it in while it still appears healthy.
''This crater, Victoria, is a window back into the ancient environment of
Mars,'' said Alan Stern, the NASA associate administrator who authorized the
move.
''Entering this crater does come with some unknowns,'' Stern added. ''We have
analyzed the entry point but we can't be certain about the terrains and the
footing down in the crater until we go there. We can't guarantee, although we
think we are likely to come back out of the crater.''
Opportunity and its twin, Spirit, have been exploring opposite sides of Mars
since landing in January 2004, discovering geologic evidence of rocks altered by
water from a long-ago wetter period of the now-dusty planet.
Blasted open by a meteor impact, Victoria Crater is a half-mile across and about
200 to 230 feet deep -- far deeper than anything else the rovers have explored.
''Because it's deeper it provides us access to just a much longer span of
time,'' said Steve Squyres, the principal investigator of the Mars Exploration
Rover mission from Cornell University in Ithaca, N.Y. He said it's not known
just how much time is represented in the crater's layered walls.
Opportunity's first target will be a band of bright material like a bathtub ring
about 10 feet below the crater's rim.
''That was the original, pre-impact surface so this bright stuff is the stuff
that was in contact with the Martian atmosphere at the time Victoria formed,
which may have been billions of years ago,'' Squyres said.
The initial entry is expected on July 7 or 9. To get into the crater, the rover
will have to safely cross a ripple of wind-formed material at the lip of the
crater, the kind of feature that has given it trouble before. The team plans to
initially drive only far enough to have all six wheels on the slope and then
back up to the top, to analyze how it performed.
''We call that a toe dip,'' said John Callas, the rover project manager at
NASA's Jet Propulsion Laboratory in Pasadena.
Since inception, the twin-rover mission has cost more than $900 million, and now
costs $20 million to $24 million annually. Planned to last 90 days, the mission
is in its fourth extension and another proposal would continue operations to the
end of October 2008.
PASADENA, Calif. (AP) -- The Mars rover Spirit has uncovered the strongest
evidence yet that the planet used to be wetter than previously thought,
scientists reported Monday.
The robot analyzed a patch of soil in Gusev Crater and found it unusually rich
in silica. The presence of water would have been necessary to produce such a
large silica deposit, scientists said.
''This is a remarkable discovery,'' principal investigator Steve Squyres of
Cornell University said in a statement. ''It makes you wonder what else is still
out there.''
Spirit previously found clues of ancient water in the crater through the
presence of sulfur-rich soil, water-altered minerals and explosive volcanism.
But the latest find is compelling because of the high silica content,
researchers said, raising the possibility that conditions may have been
favorable for the emergence of primitive life.
It's unclear how the silica deposit formed. One possibility is that the soil
mixed with acid vapors in the presence of water. Others believe the deposit was
created from water in a hot spring surrounding.
The durable Spirit and its twin, Opportunity, have been working on overtime
since completing their primary, three-month mission in 2004.
For eight months, Opportunity has explored the rim of Victoria Crater on the
opposite side of the planet. Scientists are looking for a safe opening to send
the rover in.
The mission is managed at NASA's Jet Propulsion Laboratory in Pasadena.
CAPE CANAVERAL, Fla. (AP) -- How do you get rid of the body of a dead
astronaut on a three-year mission to Mars and back?
When should the plug be pulled on a critically ill astronaut who is using up
precious oxygen and endangering the rest of the crew? Should NASA employ DNA
testing to weed out astronauts who might get a disease on a long flight?
With NASA planning to land on Mars 30 years from now, and with the recent
discovery of the most ''Earth-like'' planet ever seen outside the solar system,
the space agency has begun to ponder some of the thorny practical and ethical
questions posed by deep space exploration.
Some of these who-gets-thrown-from-the-lifeboat questions are outlined in a NASA
document on crew health obtained by The Associated Press through a Freedom of
Information Act request.
NASA doctors and scientists, with help from outside bioethicists and medical
experts, hope to answer many of these questions over the next several years.
''As you can imagine, it's a thing that people aren't really comfortable talking
about,'' said Dr. Richard Williams, NASA's chief health and medical officer.
''We're trying to develop the ethical framework to equip commanders and mission
managers to make some of those difficult decisions should they arrive in the
future.''
One topic that is evidently too hot to handle: How do you cope with sexual
desire among healthy young men and women during a mission years long?
Sex is not mentioned in the document and has long been almost a taboo topic at
NASA. Williams said the question of sex in space is not a matter of crew health
but a behavioral issue that will have to be taken up by others at NASA.
The agency will have to address the matter sooner or later, said Paul Root
Wolpe, a bioethicist at the University of Pennsylvania who has advised NASA
since 2001.
''There is a decision that is going to have to be made about mixed-sex crews,
and there is going to be a lot of debate about it,'' he said.
The document does spell out some health policies in detail, such as how much
radiation astronauts can be exposed to from space travel (No more radiation than
the amount that would increase the risk of cancer by 3 percent over the
astronaut's career) and the number of hours crew members should work each week
(No more than 48 hours).
But on other topics -- such as steps for disposing of the dead and cutting off
an astronaut's medical care if he or she cannot survive -- the document merely
says these are issues for which NASA needs a policy.
''There may come a time in which a significant risk of death has to be weighed
against mission success,'' Wolpe said. ''The idea that we will always choose a
person's well-being over mission success, it sounds good, but it doesn't really
turn out to be necessarily the way decisions always will be made.''
For now, astronauts and cosmonauts who become critically sick or injured at the
international space station -- something that has never happened -- can leave
the orbiting outpost 220 miles above Earth and return home within hours aboard a
Russian Soyuz space vehicle.
That wouldn't be possible if a life-and-death situation were to arise on a
voyage to Mars, where the nearest hospital is millions of mile away.
Moreover, Mars-bound astronauts will not always be able to rely on instructions
from Mission Control, since it would take nearly a half-hour for a question to
be asked and an answer to come back via radio.
Astronauts going to the moon and Mars for long periods of time must contend with
the basic health risks from space travel, multiplied many times over: radiation,
the loss of muscle and bone, and the psychological challenges of isolation.
NASA will consider whether astronauts must undergo preventive surgery, such as
an appendectomy, to head off medical emergencies during a mission, and whether
astronauts should be required to sign living wills with end-of-life
instructions.
The space agency also must decide whether to set age restrictions on the crew,
and whether astronauts of reproductive age should be required to bank sperm or
eggs because of the risk of genetic mutations from radiation exposure during
long trips.
Already, NASA is considering genetic screening in choosing crews on the
long-duration missions. That is now prohibited.
''Genetic screening must be approached with caution ... because of limiting
employment and career opportunities based on use of genetic information,''
Williams said.
NASA's three major tragedies resulting in 17 deaths -- Apollo 1, Challenger and
Columbia -- were caused by technical rather than medical problems. NASA never
has had to abort a mission because of health problems, though the Soviet Union
had three such episodes.
Some believe the U.S. space agency has not adequately prepared for the
possibility of death during a mission.
''I don't think they've been great at dealing with this type of thing in the
past,'' said former astronaut Story Musgrave, a six-time space shuttle flier who
has a medical degree. ''But it's very nice that they're considering it now.''
