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Improbable Bulls-Eye

NASA Space Placeby Dr. Tony Phillips

Comet Tempel 1, as seen by the Deep Impact impactors camera. Three last-minute AutoNav-controlled impact correction maneuvers enabled the Impactor to hit the bulls-eye.
Picture this: Eighty-eight million miles from Earth, a robot spacecraft plunges into a billowing cloud almost as wide as the planet Jupiter. It looks around. Somewhere in there, among jets of gas and dust, is an icy nugget invisible to telescopes on Eartha 23,000 mph moving target.

The ship glides deeper into the cloud and jettisons its cargo, the "impactor." Bulls-eye! A blinding flash, a perfect strike.

As incredible as it sounds, this really happened on the 4th of July, 2005. Gliding through the vast atmosphere of Comet Tempel 1, NASAs Deep Impact spacecraft pinpointed the comets 3x7-mile wide nucleus and hit it with an 820-lb copper impactor. The resulting explosion gave scientists their first look beneath the crust of a comet.

Thats navigation.

Credit the JPL navigation team. By sending commands from Earth, they guided Deep Impact within sight of the comets core. But even greater precision would be needed to strike the comets spinning, oddly-shaped nucleus.

On July 3rd, a day before the strike, Deep Impact released the impactor. No dumb hunk of metal, the impactor was a spaceship in its own right, with its own camera, thrusters and computer brain. Most important of all, it had "AutoNav."

AutoNav, short for Autonomous Navigation, is a computer program full of artificial intelligence. It uses a camera to see and thrusters to steerno humans required. Keeping its "eye" on the target, AutoNav guided the impactor directly into the nucleus.

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Newest Weather Sentry Takes Up Watch

NASA Space Placeby Patrick L. Barry

NOAA-18, the newest in a long line of weather and environmental satellites, launched May 20, 2005.
Today, we've become accustomed to seeing images of the Earth's swirling atmosphere from space every night on the evening news. Before 1960, no one had ever seen such images. The first-ever weather satellite was launched that year, kicking off a long line of weather satellites that have kept a continuous watch on our planet's fickle atmosphere45 years and counting! The high-quality, extended weather forecasts that these satellites make possible have become an indispensable part of our modern society, helping commercial aircraft, recreational boaters, and even military operations avoid unnecessary risk from hazardous weather. But satellites don't last forever. Parts wear out, radiation takes its toll, and atmospheric drag slowly pulls the satellite out of orbit. Many weather satellites have a design life of only 2 years, though often they can last 5 or 10 years, or more. A steady schedule of new satellite launches is needed to keep the weather report on the news each night. In May 2005, NASA successfully launched the latest in this long line of weather satellites. Dubbed NOAA-N at launch and renamed NOAA-18 once it reached orbit, this satellite will take over for the older satellite NOAA-16, which was launched in September 2000. NOAA always keeps at least two satellites in low-Earth orbit, circling the poles 14 times each day, explains Wilfred E. Mazur, Polar Satellite Acquisition Manager, NOAA/NESDIS. As Earth rotates, these satellites end up covering Earths entire surface each day. In fact, with two satellites in orbit, NOAA covers each spot on the Earth four times each day, twice during the day and twice at night, Mazur says.

By orbiting close to Earth (NOAA-18 is only 870 km above the ground), these low-Earth orbit satellites provide a detailed view of the weather. The other type of weather satellite, geosynchronous, orbits much farther out at 35,786 km. At that altitude, geosynchronous satellites can keep a constant watch on whole continents, but without the kind of detail that NOAA-18 can provide. In particular, low-Earth orbiting satellites have the ability to use microwave radiometers to measure temperature and moisture in the atmospheretwo key measurements used for weather prediction that, for technical reasons, cannot be sensed by distant geosynchronous satellites. With NOAA-18 successfully placed in orbit, the 45-year legacy of high-tech weather forecasts that we're accustomed to will go on.

Find out more about NOAA-18 and the history of polar-orbiting weather satellites at http://goespoes.gsfc.nasa.gov/poes. For kids and anyone else curious about the concept, the difference between polar and geosynchronous orbits is explained at http://spaceplace.nasa.gov/en/kids/goes/goes_poes_orbits.shtml .

This article was provided by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.
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Moving a Mountain of a Dish

NASA Space Placeby Patrick L. Barry

Giant Deep Space Network antenna in Madrid is moved using four 12-axle, 24-wheel crawlers. (Click here for larger image.)
Your first reaction: "That’s impossible!

How on earth could someone simply pick up one of NASA’s giant Deep Space Network (DSN) antennas—a colossal steel dish 12 stories high and 112 feet across that weighs more than 800,000 pounds—move it about 80 yards, and delicately set it down again?

Yet that's exactly what NASA engineers recently did.

One of the DSN dishes near Madrid, Spain, needed to be moved to a new pad. And it had to be done gingerly; the dish is a sensitive scientific instrument full of delicate electronics. Banging it around would not do.

“It was a heck of a challenge,” says Benjamin Saldua, the structural engineer at JPL who was in charge of the move. “But thanks to some very careful planning, we pulled it off without a problem!”

The Deep Space Network enables NASA to communicate with probes exploring the solar system. Because Earth is constantly rotating, a single antenna on the ground can communicate with a probe for only part of the day, when the probe is overhead. By placing large dishes at three locations around the planet—Madrid, California, and Australia—NASA can maintain contact with spacecraft around the clock.
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Seeing in the Dark with Spitzer

NASA Space Placeby Patrick Barry and Tony Phillips

Artist’s rendering of brown dwarf OTS44 with its rotating planetary disk. (Click for larger image.)
Have you ever gotten up in the middle of the night, walked to the bathroom and, in the darkness, tripped over your dog? A tip from the world of high-tech espionage: next time use night-vision goggles.

Night vision goggles detect heat in the form of infrared radiation—a "color" normally invisible to the human eye. Wearing a pair you can see sleeping dogs, or anything that’s warm, in complete darkness.

This same trick works in the darkness of space. Much of the exciting action in the cosmos is too dark for ordinary telescopes to see. For example, stars are born in the heart of dark interstellar clouds. While the stars themselves are bright, their birth-clouds are dense, practically impenetrable. The workings of star birth are thus hidden.

That's why NASA launched the Spitzer Space Telescope into orbit in 2003. Like a giant set of infrared goggles, Spitzer allows scientists to peer into the darkness of space and see, for example, stars and planets being born. Dogs or dog stars: infrared radiation reveals both.

There is one problem, though, for astronomers. "Infrared telescopes on the ground can't see very well," explains Michelle Thaller, an astronomer at the California Institute of Technology. "Earth's atmosphere blocks most infrared light from above. It was important to put Spitzer into space where it can get a clear view of the cosmos."

The clear view provided by Spitzer recently allowed scientists to make a remarkable discovery: They found planets coalescing out of a disk of gas and dust that was circling—not a star—but a "failed star" not much bigger than a planet! Planets orbiting a giant planet?
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Hope for the Hubble?

NASA Space PlaceBy Richard Tresch Fienberg

NASA's new chief, Michael D. Griffin, has told the Hubble servicing team at the Goddard Space Flight Center in Maryland to resume preparations for a possible shuttle flight to upgrade the orbiting observatory. Although a decision on returning astronauts to Hubble won't be made until after at least two successful shuttle missions to the International Space Station, the telescope's prospects look better now than they have at any time since Griffin's predecessor, Sean O'Keefe, abruptly canceled Hubble servicing in January 2004 — a decision that outraged astronomers, key members of Congress, and the public.

At his Senate confirmation hearing in early April, Griffin said he would consider reauthorizing a Hubble house call once the shuttle was flying again. But after just two weeks on the job he called a press conference to announce a two-month slip in the first post-Columbia launch, from mid-May to mid-July. This means that the second of two "return-to-flight" missions won't occur before September. By then there may not be enough time to mount a servicing mission that would reach Hubble before its electronics give out. So, said Griffin, "what we're going to be doing is getting the...folks at Goddard started on the work that they would have to do if a servicing flight can yet be done."

Griffin reiterated that a robotic servicing mission, once offered as a less risky alternative to a shuttle flight, is no longer under consideration. Robotic servicing "is just not feasible within the time and the money that we have to allow for it," said Griffin. "So that's off the table."

Astronauts have serviced Hubble four times between 1993 and 2002, replacing failed components and installing new instruments. If they do it again, they'll have three main goals. One is to extend the spacecraft's operational lifetime by replacing its onboard gyroscopes and batteries. Another is to upgrade the telescope's scientific capabilities by installing a new camera and spectrograph. The third and most important task is to attach a retrorocket module that will steer Hubble to a harmless splashdown in the Pacific Ocean at the end of its mission early in the next decade. If the shuttle's return to flight doesn't go as planned, or if something else happens to preclude servicing Hubble, NASA probably will instead fly a limited robotic mission just to attach the deorbit module.
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Asian Tsunami Seen from Space

NASA Space Placeby Patrick L. Barry

This December 26, 2004, MISR image of the southern tip of Sri Lanka was taken several hours after the first tsunami wave hit the island. It was taken with MISR’s 46° forward-looking camera.
When JPL research scientist Michael Garay first heard the news that a tsunami had struck southern Asia, he felt the same shock and sadness over the tremendous loss of human life that most people certainly felt. Later, though, he began to wonder: were these waves big enough to see from space?

So he decided to check. At JPL, Garay analyzes data from MISR—the Multi-angle Imaging SpectroRadiometer instrument aboard NASA's Terra satellite. He scoured MISR images from the day of the tsunami, looking for signs of the waves near the coasts of India, Sri Lanka, Indonesia, and Thailand.

Looking at an image of the southern tip of Sri Lanka taken by one of MISR's angled cameras, he spotted the distinct shape of waves made visible by the glint of reflected sunlight. They look a bit like normal waves, except for their scale: These waves were more than a kilometer wide!

Most satellites have cameras that point straight down. From that angle, waves are hard to see. But MISR is unique in having nine cameras, each viewing Earth at a different angle. “We could see the waves because MISR's forward-looking camera caught the reflected sunlight just right,” Garay explains.

In another set of images, MISR’s cameras caught the white foam of tsunami waves breaking off the coast of India. By looking at various angles as the Terra satellite passed over the area, MISR’s cameras snapped seven shots of the breaking waves, each about a minute apart. This gave scientists a unique time-lapse view of the motion of the waves, providing valuable data such as the location, speed, and direction of the breaking waves.
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October Sky - Live, Distance Learning Event

NASA Space PlaceThe NASA Glenn Research Center in partnership with the Cleveland Area Metropolitan Library System will be conducting a live 60 minute discussion with Homer Hickam author of the #1 New York Times Bestseller Rocket Boys and inspiration for the hit movie October Sky on April 14, 2005 from 11:30am EST to 12:30pm EST. Rocket Boys by Homer Hickam, is the true story of the author's life growing up in the mining town of Coalwood, West Virginia. In October 1957, Sputnik raced across the Appalachian sky, leaving in its wake 14-year old Homer's dream to build rockets. With the help of his friends, a dedicated teacher, his mother, and others in his small, company town, Homer's rockets would carry him, and his town, farther than he ever expected.

The free live broadcast, webcast, and videoconference will feature Homer Hickam discussing his inspirational life story and the key people who helped him along the way. The program will feature numerous opportunities for students and the public to interact with the author through email.

For Additional Information, Related Activities and Connection Details Visit: http://www.nasa.gov/centers/glenn/education/
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Utterly Alien

NASA Space Placeby Dr. Tony Phillips

New Horizons spacecraft will get a gravity assist from Jupiter on its long journey to Pluto-Charon. Credit: Southwest Research Institute (Dan Durda)/Johns Hopkins University Applied Physics Laboratory (Ken Moscati).
There's a planet in our solar system so cold that in winter its nitrogen atmosphere freezes and falls to the ground. The empty sky becomes perfectly clear, jet-black even at noontime. You can see thousands of stars. Not one twinkles.

The brightest star in the sky is the Sun, so distant and tiny you could eclipse it with the head of a pin. There's a moon, too, so big you couldn't blot it out with your entire hand. Together, moonlight and sunshine cast a twilight glow across the icy landscape revealing . . . what? twisted spires, craggy mountains, frozen volcanoes?

No one knows, because no one has ever been to Pluto.

"Pluto is an alien world," says Alan Stern of the Southwest Research Institute in Colorado. "It's the only planet never visited or photographed by NASA space probes."

That's about to change. A robot-ship called New Horizons is scheduled to blast off for Pluto in January 2006. It's a long journey: More than 6 billion kilometers (about 3.7 billion miles). New Horizons won't arrive until 2015.
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New NASA Undergraduate Program

NASA Space PlaceThe NASA Institute for Advanced Concepts (NIAC) seeks to identify creative and innovative students who possess an extraordinary potential for developing advanced concepts in the fields of aeronautics, space and the sciences. Each Student Fellow will receive a total of $9,000 for the Academic year 2005-2006. NIAC intends for these awards to benefit talented individuals who have shown extraordinary originality and dedication in their academic pursuits and a marked capacity for self-direction. The Fellowship seeks exceptional creativity, and the promise for important future advances based on a track record of significant accomplishment, and potential for the fellowship to facilitate subsequent creative work.
  • Applicant must be in a U.S. institution of higher education.
  • Applicant must be a U.S. Person.
  • Applicant must apply no later than their junior year of college.
Please visit http://niac.usra.edu/students/call.html for more information.

Proposals are due April 15, 2005.
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Women Working on Mars: Get Involved in Robotics!

NASA Space Place
When:Thursday, February 24, 2005 -- 10:00 a.m. and 3 p.m. Pacific Time

Where: http://marsrovers.jpl.nasa.gov/gallery/video/webcast.html

In honor of "Introduce a Girl to Engineering Day", February 24, 2005, the Mars Public Engagement program and NASA's Robotics Education Project are hosting an interactive webcast for young women interested in robotics and engineering.

Ever wonder what it's like to work in robotics? Or how young people can get involved at an early age? Just tune in for the "Get Involved in Robotics!" webcast to learn more!

Students will see and hear from a diverse group of girls and women involved in science and engineering at four different stages from elementary school to full-time employment as an engineer. The 40-minute production will highlight an inside look at how you can get involved at robotics at any age. A live audience and e-mail link will provide many questions for the panelists - you can even email in your own questions and have them answered live during the show.

Following the shows, log on to the LIVE WEB CHAT and ask your questions directly of women roboticists working at NASA! Webcast panelists will include a professional engineer, an engineering student in college, a high school student interested in engineering, and our youngest, an elementary student just learning about the world of engineering and Mars.

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