The U.S. space agency, NASA, hopes to provide the world with spectacular new images of Mars next year to surpass the ones it got in 1997. That was when a robotic explorer captured world attention by rolling around the barren Martian terrain and taking pictures of rocks and the immediate landscape. A NASA launch set for Sunday, June 8 at 2:02 p.m. EDT, and a second one, two-and-a-half weeks later, are to send two more rovers to our celestial neighbor.
NASA seems wistful about its Mars landing success of 1997. The attempt to land another rover there in 1999 failed, so the space agency is redoubling its effort. It is dispatching two robotic explorers for January arrivals.
The 1997 mission was unprecedented for its novel landing technology. After the Pathfinder lander raced through the atmosphere, it deployed a parachute and dropped safely in an airbag that inflated to cushion its impact. When the bag deflated, the orbiter opened up like a flower. Out rolled the four-wheeled robot down a ramp ready for business.
The subsequent lander two-years later was to have touched down the old fashioned way, with retrorockets slowing its descent. No one is blaming its failure on this technology. An investigation said the cause was management failures and overworked engineers and scientists.
Nevertheless, NASA is returning to the 1997 drop, bounce, and roll technology for this year's missions. This time, however, the product will be two, much larger rovers with more advanced technology.
"This mission is going to be, I truly believe, humanity's first great voyage of exploration of this new millennium," said astronomer Stephen Squyres of Cornell University in Ithaca, New York, the institution that is providing some of the science instruments the two rovers will use on Mars.
Mr. Squyres said their task is to read the planet's surface just as human geologists do on Earth.
"In essence, what you would be doing would be reading the geologic record to look at the story that is told by the rocks - to look inside them and to find out what conditions were like long ago," he explained. "Was it warm? Was it wet? Was it habitable? That is what this machine does."
But the rovers are more capable than the 1997 model. Both units will be identical, with a range of 100 meters a day, the distance it took the old one three-months to cover. The new ones will have five instruments, including a panoramic camera to take landscape vistas and an infrared camera to detect minerals present in the Martian soil. According to NASA scientist Jim Garvin, a third, microscopic camera will get the closest views ever of rocks on another planet.
"This mission is all about new scales and new perspectives. Seeing the actual grains that make up the building blocks of the rocks for the first time is in itself a major discovery, no matter what it shows," he said.
Other rover instruments will scrape stones to expose fresh surfaces and measure concentrations of their elements. The new robot generation will also be smarter than the 1997 one, with more powerful computing capability.
Cornell's Stephen Squyres said the rovers can be ordered to a nearby Martian destination and get there on their own, without specific commands from Earth.
"There are cameras out in front that can look ahead and look for obstacles," he points out. "When we get to an obstacle, the rover is able to spot it, recognize it, and steer around it all by itself."
The goal of this $800 million effort is to seek evidence of past water in the Martian geologic record. As NASA's Jim Garvin said, water suggests microbial life may have once existed there.
"There are lots of fingerprints of the activity of water on Mars," he said. "Finding what is going on in those places up close is what we need to do. That is what this mission is about."
NASA selected targets on opposite sides of the red planet where the two rovers will roam to help answer the question, where did Mars' water go? NASA's former Mars Program Director, Scott Hubbard, points out that the strength of the dual rover concept is that the loss of one would not mean complete mission failure in this quest.
"We think this twin rover mission will allow us to move even further toward answering that type of question," he said.
