VOICE ONE:
This is Doug Johnson.
VOICE TWO:
And this is Sarah Long with the VOA Special English program EXPLORATIONS. Today, we report about the planet Mars. We tell about evidence that weather on Mars is changing. We tell about plans for a new kind of vehicle to explore Mars. And we tell about the Mars Odyssey spacecraft that recently began orbiting the planet.
((THEME))
VOICE ONE:
National Aeronautics and Space Administration officials are using the atmosphere of Mars to slow the Mars Odyssey spacecraft. The slowing of spacecraft also permits it to fly much closer to the planet.
The Two-Thousand-One Mars Odyssey spacecraft arrived at Mars in October. Its early orbit around the planet was extremely high. The orbit was so high the spacecraft took eighteen and one half-hours to circle the planet. Today, the Mars Odyssey is much lower and closer to the planet. It now takes only three hours and fifteen minutes to make one complete orbit of the planet.
VOICE TWO:
David Spencer is the head of the Mars Odyssey project at NASA’s Jet Propulsion Laboratory in Pasadena, California. Mister Spencer says it will take most of the month of January to get the Mars Odyssey in exactly the right orbit. He says the two and one-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 the Mars 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. The surface has long been thought to be a mix of rock, soil and ice material. Odyssey will provide images that will help scientists identify the minerals that are in the soils and rocks on the surface.
Mars Odyssey also carries instruments that can measure hydrogen in the upper meter of soil. It will search for evidence of water. It will study the soil and other materials in areas that may be used for future landings.
The spacecraft will also look for radiation risks that could affect any future human explorers. And it will act as a communications link for future spacecraft that land on Mars.
((MUSIC BRIDGE))
VOICE TWO:
NASA researchers are developing several new devices that will explore the surface of Mars. These devices will not carry humans. They will carry several different scientific devices and instruments. The devices are called robots.
NASA researchers hope to design a series of robots that will be able to work together, or work alone on the surface of Mars. Each robot will look like a small vehicle with four wheels. Researchers hope the robots will be able to climb very steep areas of the planet surface.
VOICE ONE:
Paul Schenker is the head of the Mechanical and Robotics Technologies Group at NASA’s Jet Propulsion Laboratory. He is also the chief investigator for the robot project. Mister Schenker says the robots will be able to climb up hills or down into deep valleys to study the surface.
In a recent test in California, two robots helped a third robot safely climb down a side of a hill that dropped sharply. These robots were linked together with a long device called a tether. Mister Schenker said the test showed the robots can work as a true team. They use extremely small computers to share the important information their instruments gather.
Mister Schenker says the small robots communicate with each other, make informed decisions, and jointly work to control actions. He says you can think of them as one mountain climber with two good friends that help.
VOICE TWO:
In the past year, NASA researchers also successfully developed and demonstrated a single robot that can move over difficult surface areas. It can move up and over hills that rise sharply.
Researchers say the robot is similar to a small animal. It uses cameras 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. They could be used to search for water or minerals.
These robots are called All Terrain Explorer Rovers. They may be part of a future Mars flight. They will be used to explore the hills, valleys, and hard to reach areas of the Mars.
VOICE ONE:
One of the most unusual devices that may be sent to explore Mars is a large round rubber ball. Researchers hope to use the winds of Mars to move the large balls across long distances. Researchers have begun 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 the ground and blow them across the sand.
Researchers accidentally discovered the idea of the wind driven ball. They were testing a vehicle that has ball shaped wheels. One of the wheels came off the device. The wind blew the round wheel across the ground so quickly that researchers could not catch it.
Researchers who are testing the Tumbleweed Rovers say they will be cheap to produce. Many could be sent to Mars. The tumbleweed rovers 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 new idea. The Mars Pathfinder spacecraft successfully landed on Mars in July, Nineteen-Ninety-Seven. The Pathfinder carried a small robot called Sojourner, named for the American civil rights worker, Sojourner Truth. The little robot outlived its expected working life by almost twelve days.
It sent back more than five-hundred-fifty pictures as well as more than fifteen chemical tests of rocks and soil. It also sent back information on winds and other weather information.
The Sojourner rover robot provided the first evidence that suggests that Mars was warmer and wetter at one time in its past. Researchers are excited about what kind of information future robots will provide when they reach Mars.
((MUSIC BRIDGE))
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. New observations by NASA’s Mars Global Surveyor spacecraft are expanding our understanding of the Martian climate.
NASA scientists say new evidence suggests large climate changes have taken place during the planet’s recent history. They say even larger changes may take place in its future. They say it is possible Mars may become warmer and wetter as some scientists say it was in its early history.
The scientists say the climate evidence was gathered during one Martian year. One Martian year is equal to six-hundred-eighty-seven Earth days.
VOICE TWO:
Pictures from Global Surveyor’s camera system show that holes in the surface of the ice at the southern pole of Mars have increased greatly in size in the past year. NASA scientists say this shows that heat below the surface has caused material to change from frozen liquid into gas, which escapes into the atmosphere.
Michael Malin is chief investigator for the Global Surveyor’s camera 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 linked to the increased size of the holes in the ice at the Martian south pole. He said if this is true, it is more likely that water was present as a liquid near the surface. The presence of liquid water on Mars would make it more likely life may once have existed on the planet.
VOICE ONE:
James Garvin is NASA’s top scientist for Mars Exploration. He says that finding evidence of climate change on Mars is important information.
Mister Garvin says information gathered by the Mars Global Surveyor will tell where landings of other spacecraft should be made in the next ten years. He said the information shows that polar areas should be good places to search for evidence of hot water produced deep below the surface of Mars.
Experts say the Global Surveyor is continuing to provide important information that helps in understanding Martian climate of the past. And they say the spacecraft is continuing to provide information about what might happen to the climate of the planet Mars in the future.
((THEME))
VOICE TWO:
This Special English program was written by Paul Thompson. Our director was Cynthia Kirk. Our studio engineer was Mick Shaw. This is Sarah Long.
VOICE ONE:
And this is Doug Johnson. Join us again next week for another EXPLORATIONS program on the Voice of America.