VOICE ONE:
This is Doug Johnson.
VOICE TWO:
And this is Sarah Long with theVOA Special English program EXPLORATIONS. Today, we report about theplanet Mars. We tell about evidence that weather on Mars ischanging. We tell about plans for a new kind of vehicle to exploreMars. And we tell about the Mars Odyssey spacecraft that recentlybegan orbiting the planet.
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VOICE ONE:
National Aeronautics and Space Administration officials are usingthe atmosphere of Mars to slow the Mars Odyssey spacecraft. Theslowing of spacecraft also permits it to fly much closer to theplanet.
The Two-Thousand-One Mars Odyssey spacecraft arrived at Mars inOctober. Its early orbit around the planet was extremely high. Theorbit was so high the spacecraft took eighteen and one half-hours tocircle the planet. Today, the Mars Odyssey is much lower and closerto the planet. It now takes only three hours and fifteen minutes tomake one complete orbit of the planet.
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David Spencer is the head of the Mars Odyssey project at NASA’sJet Propulsion Laboratory in Pasadena, California. Mister Spencersays it will take most of the month of January to get the MarsOdyssey in exactly the right orbit. He says the two andone-half-year science mission will begin when the orbit is correct,which should be in February.
NASA experts have been testing the science instruments on theMars Odyssey. They say the instruments are working correctly.
VOICE ONE:
The Mars Odyssey spacecraft was launched in April,Two-Thousand-One. Its main task is to study the surface of Mars. Thesurface has long been thought to be a mix of rock, soil and icematerial. Odyssey will provide images that will help scientistsidentify the minerals that are in the soils and rocks on thesurface.
Mars Odyssey also carries instruments that can measure hydrogenin the upper meter of soil. It will search for evidence of water. Itwill study the soil and other materials in areas that may be usedfor future landings.
The spacecraft will also look for radiation risks that couldaffect any future human explorers. And it will act as acommunications link for future spacecraft that land on Mars.
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VOICE TWO:
NASA researchers are developing several new devices that willexplore the surface of Mars. These devices will not carry humans.They will carry several different scientific devices andinstruments. The devices are called robots.
NASA researchers hope to design a series of robots that will beable to work together, or work alone on the surface of Mars. Eachrobot will look like a small vehicle with four wheels. Researchershope the robots will be able to climb very steep areas of the planetsurface.
VOICE ONE:
Paul Schenker is the head of the Mechanical and RoboticsTechnologies Group at NASA’s Jet Propulsion Laboratory. He is alsothe chief investigator for the robot project. Mister Schenker saysthe robots will be able to climb up hills or down into deep valleysto study the surface.
In a recent test in California, two robots helped a third robotsafely climb down a side of a hill that dropped sharply. Theserobots were linked together with a long device called a tether.Mister Schenker said the test showed the robots can work as a trueteam. They use extremely small computers to share the importantinformation their instruments gather.
Mister Schenker says the small robots communicate with eachother, make informed decisions, and jointly work to control actions.He says you can think of them as one mountain climber with two goodfriends that help.
VOICE TWO:
In the past year, NASA researchers also successfully developedand demonstrated a single robot that can move over difficult surfaceareas. It can move up and over hills that rise sharply.
Researchers say the robot is similar to a small animal. It usescameras that perform like eyes to look at objects blocking the way,make decisions and then move over the objects or around them.
The robots could carry many different kinds of instruments. Theycould be used to search for water or minerals.
These robots are called All Terrain Explorer Rovers. They may bepart of a future Mars flight. They will be used to explore thehills, valleys, and hard to reach areas of the Mars.
VOICE ONE:
One of the most unusual devices that may be sent to explore Marsis a large round rubber ball. Researchers hope to use the winds ofMars to move the large balls across long distances. Researchers havebegun calling the balls “Tumbleweed Rovers.”
The name comes from a plant that grows in the American southwest.Winds in the desert often tear the tumbleweed plants loose from theground and blow them across the sand.
Researchers accidentally discovered the idea of the wind drivenball. They were testing a vehicle that has ball shaped wheels. Oneof the wheels came off the device. The wind blew the round wheelacross the ground so quickly that researchers could not catch it.
Researchers who are testing the Tumbleweed Rovers say they willbe cheap to produce. Many could be sent to Mars. The tumbleweedrovers could carry inside them science instruments to seek water.Researches say this could be another way to find water on Mars.
VOICE TWO:
The use of a robot device to explore the planet Mars is not a newidea. The Mars Pathfinder spacecraft successfully landed on Mars inJuly, Nineteen-Ninety-Seven. The Pathfinder carried a small robotcalled Sojourner, named for the American civil rights worker,Sojourner Truth. The little robot outlived its expected working lifeby almost twelve days.
It sent back more than five-hundred-fifty pictures as well asmore than fifteen chemical tests of rocks and soil. It also sentback information on winds and other weather information.
The Sojourner rover robot provided the first evidence thatsuggests that Mars was warmer and wetter at one time in its past.Researchers are excited about what kind of information future robotswill provide when they reach Mars.
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VOICE ONE:
The planet Mars we know today is a cold, dry, desert-like world.Yet there is some evidence that its climate is changing. Newobservations by NASA’s Mars Global Surveyor spacecraft are expandingour understanding of the Martian climate.
NASA scientists say new evidence suggests large climate changeshave taken place during the planet’s recent history. They say evenlarger changes may take place in its future. They say it is possibleMars may become warmer and wetter as some scientists say it was inits early history.
The scientists say the climate evidence was gathered during oneMartian year. One Martian year is equal to six-hundred-eighty-sevenEarth days.
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Pictures from Global Surveyor’s camera system show that holes inthe surface of the ice at the southern pole of Mars have increasedgreatly in size in the past year. NASA scientists say this showsthat heat below the surface has caused material to change fromfrozen liquid into gas, which escapes into the atmosphere.
Michael Malin is chief investigator for the Global Surveyor’scamera system at Malin Space Science systems in San Diego,California. He says the frozen liquid may be carbon dioxide ice.
Mister Malin says changes in atmospheric pressure could be linkedto the increased size of the holes in the ice at the Martian southpole. He said if this is true, it is more likely that water waspresent as a liquid near the surface. The presence of liquid wateron Mars would make it more likely life may once have existed on theplanet.
VOICE ONE:
James Garvin is NASA’s top scientist for Mars Exploration. Hesays that finding evidence of climate change on Mars is importantinformation.
Mister Garvin says information gathered by the Mars GlobalSurveyor will tell where landings of other spacecraft should be madein the next ten years. He said the information shows that polarareas should be good places to search for evidence of hot waterproduced deep below the surface of Mars.
Experts say the Global Surveyor is continuing to provideimportant information that helps in understanding Martian climate ofthe past. And they say the spacecraft is continuing to provideinformation about what might happen to the climate of the planetMars in the future.
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VOICE TWO:
This Special English program was written by Paul Thompson. Ourdirector was Cynthia Kirk. Our studio engineer was Mick Shaw. Thisis Sarah Long.
VOICE ONE:
And this is Doug Johnson. Join us again next week for anotherEXPLORATIONS program on the Voice of America.