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Mars Lander Team Prepares for "Seven Minutes of Terror"
National Geographic News ^ | 5-13-2008 | Lander Team Prepares for "Seven Minutes of Terror"<b>Victoria Jaggard

Posted on 05/13/2008 8:24:55 PM PDT by blam

Mars Lander Team Prepares for "Seven Minutes of Terror"

Victoria Jaggard
National Geographic News
May 13, 2008

After years of planning followed by a ten-month journey, the Mars Phoenix Lander is slated to touch down on the red planet's north pole on May 25.

If successful, the probe will be the first lander to reach a Martian pole and the first to actually touch the planet's water ice.

What's more, it could settle the debate over whether Mars was once a habitable world.

Now, as Phoenix closes in on the last 12 million miles (19 million kilometers) of its journey, NASA scientists are gearing up for the "seven minutes of terror" that could make or break the $420-million mission.

"Approximately 14 minutes before touchdown, the vehicle separates from its cruise stage," Barry Goldstein, Phoenix project manager at the Jet Propulsion Laboratory in California, said today at a press conference.

"At this point we lose communication from the vehicle."

Once the craft reaches Mars's atmosphere, the next critical seven minutes make up what's known as the Entry, Descent, and Landing (EDL) phase.

Screaming down at about 12,600 miles (20,270 kilometers) an hour, the craft must open a parachute to slow itself for a three-minute glide to the surface about 70 miles (113 kilometers) below.

The craft's landing sequence then includes steps such as jettisoning its heat shield, extending its legs, and firing its landing thrusters.

"There are 14 pyrotechnic events, and each of those have to work perfectly for this to go as planned," Goldstein said. "Getting EDL communication [at touchdown]—that'll be the three seconds that I am really biting my nails over."

Risen From the Ashes

The tension for this mission seems especially intense, since Phoenix is not the first craft to attempt a landing at a Martian pole. In 1999 NASA lost communication with the Mars Polar Lander as it entered the atmosphere above the planet's south pole.

That lander's fate remains a mystery, but its hardware designs will be given a second chance—Phoenix is based on much of the lost craft's systems.

"We spent 15 years developing the hardware, and I really wanted some return from those," said Peter Smith, Phoenix principal investigator at the University of Arizona in Tucson, who first proposed "recycling" technology from the failed 1999 mission.

Engineers have put the so-called heritage hardware through a battery of tests, and NASA scientists say they have fixed all the known issues.

Teams using a variety of data also put serious thought into where exactly to set the lander down.

"Finding a place to land that was scientifically interesting and safe … has been a multiyear process," noted Ray Arvidson, chair of the Phoenix landing site working group at Washington University in St. Louis, Missouri.

The site, informally dubbed Green Valley, sits in a region of permafrost on Mars's northern plains that is analogous to northern Canada, JPL's Smith said.

The relatively shallow valley, which contains some of the highest concentrations of ice outside of the polar cap, is about 700 feet (213 meters) deep and stretches for 40 miles (64 kilometers).

A crater near the valley means that an impact pushed away most large rocks and spread out a soft cushion of fine particles 5 to 10 inches (13 to 25 centimeters) deep on top of the hard icy soil.

But "this is no trip to grandma's for the weekend," warned Ed Weiler, NASA's associate administrator for the Science Mission Directorate.

"Mars has been known to cause trouble, and I'll be worried until I hear the signal a few seconds after landing."

Search for Life

Still, NASA team members said that the scientific payoffs of a polar mission will be well worth the risks.

As opposed to the Mars rovers that have been exploring the red planet's geologic history, Phoenix will be taking samples that should reveal active processes.

Mars's northern ice cap expands and contracts with the seasons, which should allow scientists to analyze how water impacts the planet's soil chemistry.

And "we'll look at the properties of ice frozen into the surface with water vapor in the atmosphere to see if there's a communication there," Smith said.

But the biggest goal will be to look for signatures that Mars might once have been habitable. (Get full coverage of the search for water—and life—on Mars.)

"We're really doing a full geological and chemical experiment on the surface with the idea of finding if this is a habitable zone," Smith added.

The polar region offers the best hope, he said, because just like the refrigerator in a kitchen, polar ice may "preserve organic material and the history of life on this planet."

The consequence, however, is that the craft is not expected to last beyond the stated lifetime of the mission.

Unlike the Mars rovers that have roamed Mars's equatorial zone since 2004, Phoenix is touching down in a region that within months will be too cold and dark for the craft to maintain power supplies.

"Living in Hawaii would be wonderful, but we live north of the Arctic Circle," JPL's Goldstein said.

"In January [at the start of Martian winter] we'll go three to four months without any solar energy. At that point it's extraordinarily unlikely the craft will survive."


TOPICS: News/Current Events
KEYWORDS: lander; mars; pl; team; terror
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To: devolve

Bet Phil liked this, very flashy.


21 posted on 05/14/2008 3:46:39 AM PDT by potlatch
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To: devolve

Very nice posting


22 posted on 05/14/2008 3:47:31 AM PDT by potlatch
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To: Captain Beyond; potlatch


Thanks - We're always looking for space related and NASA and JPL threads

I use a lot of JPL and NASA photographs and add animated backgrounds and NASA / Hubbell photographed objects we animate

It's a shame we cannot add embedded autoloading background music to these - I can add Flash audio (.swf with embedded .wavs or .mp3s ) - but only WebTV and MSN-TV browsers will detect and play it







23 posted on 05/14/2008 3:47:42 AM PDT by devolve ( -- -The_Project_Islamic_Hope_website_banner no_longer_features_Barack_Hussein_Obama_Junior)
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To: devolve

Bumparoo


24 posted on 05/14/2008 3:48:02 AM PDT by potlatch
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To: blam

I wonder is Sheila Jackson Lee will want to see the flag the astronauts put there.


25 posted on 05/14/2008 3:49:42 AM PDT by mathluv
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To: potlatch

.

LOL!

Piper gotcha up?


26 posted on 05/14/2008 3:54:58 AM PDT by devolve ( -- -The_Project_Islamic_Hope_website_banner no_longer_features_Barack_Hussein_Obama_Junior)
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To: devolve

I haven’t been to sleep yet

signing off


27 posted on 05/14/2008 3:56:55 AM PDT by potlatch
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To: potlatch

Piper must be hungry!


28 posted on 05/14/2008 4:13:46 AM PDT by devolve ( -- -The_Project_Islamic_Hope_website_banner no_longer_features_Barack_Hussein_Obama_Junior)
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To: devolve; potlatch

click!


29 posted on 05/14/2008 8:51:18 AM PDT by PhilDragoo (Hitlery: das Butch von Buchenvald)
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To: devolve
Lol, roiling around inside the cube! Pretty post devolve, thanks for posting it to me.
30 posted on 05/14/2008 4:51:52 PM PDT by potlatch
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To: devolve

Very nice. New one I believe.


31 posted on 05/14/2008 4:53:11 PM PDT by potlatch
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To: potlatch

.

Yes - new

Just 2 .gifs there

The BG is a large 980x735 animation


32 posted on 05/14/2008 5:11:22 PM PDT by devolve ( -- -The_Project_Islamic_Hope_website_banner no_longer_features_Barack_Hussein_Obama_Junior)
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To: devolve

New one, that’s nice. Even has the space rock in it. You went to a lot of trouble. The little ‘swarmy’ thing, lol.


33 posted on 05/14/2008 5:16:14 PM PDT by potlatch
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To: potlatch

.

I get these ideas in the middle of the night!

If I don’t finish it then - It never comes out as I visualized -


34 posted on 05/14/2008 5:41:12 PM PDT by devolve ( -- -The_Project_Islamic_Hope_website_banner no_longer_features_Barack_Hussein_Obama_Junior)
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To: devolve

I think of things at bedtime and jot them down, with directions, lol.


35 posted on 05/14/2008 5:49:26 PM PDT by potlatch
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To: BlueVelvet

Welcome to FR !


36 posted on 05/14/2008 5:50:33 PM PDT by tomkat (helping keep American craftsmanship alive)
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To: potlatch

.

LOL!

I use to use a mini-recorder!


37 posted on 05/14/2008 6:10:57 PM PDT by devolve ( -- -The_Project_Islamic_Hope_website_banner no_longer_features_Barack_Hussein_Obama_Junior)
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To: devolve

[I use to use a mini-recorder!]

Nothing funny about that, it’s an excellent idea.
Just noted a new poster. Wonder how many Freepers there are now?


38 posted on 05/14/2008 6:18:52 PM PDT by potlatch
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To: tomkat

Thank you, you are the first to say that!


39 posted on 05/14/2008 6:45:44 PM PDT by BlueVelvet
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To: BlueVelvet
Thank you, you are the first to say that!

You're welcome, tho I find it rather surprising, as I'm one of the slower ones in the class . .

40 posted on 05/14/2008 6:55:09 PM PDT by tomkat (helping keep American craftsmanship alive)
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