It's Not Sci-Fi: Robots Move In on Mars
Twenty years after Voyager, the US is planning jointly with other nations to invade Mars this fall with more high-tech spacecraft
Martians beware. Here come the robot Earthlings.Skip to next paragraph
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Their forerunners temporarily set up shop 20 years ago this month when Viking 1 landed on July 20, 1976. Viking 2 followed on Sept. 3. Now the robots are coming again to set up continuing operations. It's the start of the most intensive exploration ever of another world.
Three spacecraft are due to head for Mars this fall. They're bringing along three surface stations, two soil penetrators, and a rover explorer vehicle. The United States Mars Global Surveyor will study the Red Planet from orbit. The US Pathfinder will travel on a bullet-like trajectory right to the planet's surface carrying one robot research station and the rover. Russia's Mars '96, which also will orbit Mars, carries the other two stations and the penetrators.
Planetary scientists want to really know the only other planet in the solar system they think has - or may once have had - even the remotest possibility of supporting life. So from now on, whenever Earth and Mars are favorably aligned for space travel, they hope to send their robots. That means more orbiters, landers, penetrators, and rovers arriving at Mars roughly every two years. And, by 2005, the explorers hope one of the robots will bring samples of Mars back to Earth.
Future missions are an international effort. No single nation can afford the massive exploration envisioned. The California Institute of Technology's Jet Propulsion Laboratory (JPL) in Pasadena, which manages the National Aeronautics and Space Administration's Mars program, calls international cooperation "the cornerstone" of Mars exploration.
NASA's Mars Global Surveyor carries a French-supplied radio to help relay data from the Russian landers and penetrators. The Mars Surveyor planned for 1998 will carry the first Russian instrument to fly on an American planetary craft. It's the beginning of the Mars Together cooperative program between Russia and the United States, which will include a variety of future joint projects.
Meanwhile, experts from 20 countries share in Russia's Mars '96 craft. Writing in The Planetary Report of the Pasadena-based Planetary Society, Vassili Moroz of the Russian Academy of Science's Space Research Institute notes that "the entire world planetary community is interested in the success of Mars '96."
Even the first wave of invading spacecraft promises major advances in scientists' knowledge of Mars. With these new data and the knowledge from earlier missions, "we're going to know what Mars is made of," at least roughly, says Donna Shirley, manager of the Mars exploration program office at the Jet Propulsion Laboratory.
She explains that two wide-angle cameras on the Global Surveyor orbiter will give the big picture by mapping the entire planet through changing seasons. A high resolution camera will give more detailed views of selected areas.
Using the cameras together with the orbiter's laser altimeter, researchers should "be able to really look at the topography of the planet," Dr. Shirley says. She adds that the orbiter will also collect "a lot of information" on how the atmosphere changes during the course of the Martian year, which is 687 Earth days long.
Down on the surface, the Pathfinder science station and rover will study atmosphere, rocks, and soil. The station will have a stereo imager and will work with the rover's imager to study surface-atmosphere interactions as small as a few centimeters. The bread-box-sized rover will be able to roll up to a rock and analyze what elements it contains. But this rover, named Sojourner, can't do chemical analysis. That job is left for the rover to be sent with the 1998 lander.
Pathfinder's landing site is Area Vallis. That's a location where a channel apparently caused by a catastrophic flood empties into Chryse Planitia, the Plain of Gold. It's about 500 miles from Viking 1. Mars geologists think that debris representative of a wide Martian region may be found there.
Meanwhile, Russia's Mars '96 orbiter, landers, and soil penetrators will gather data that complement the Surveyor-Pathfinder studies. The Viking landers found that Mars has a chemically reactive soil that destroys organic matter. The penetrators should reach below that surface activity. If traces of organic matter or water exist beneath the topsoil, they may find them.
These new data should ease scientists' disappointment over loss of the Mars Observer spacecraft that fell silent on Aug. 21, 1993, just prior to arrival at Mars. In fact, Mars Observer lives again in the sense that the Global Surveyor carries copies of five of the original Mars Observer experiments.