Mars Projects Aim to Settle Questions About Red Planet : Space: NASA’s Observer will begin a string of missions that probe mysteries of life, water and weather there.
In mid-September, NASA will launch a satellite that, finances permitting, will kick off a decade of Mars exploration by the United States, Russia, Europe and Japan.
The ambitious string of missions, discussed Wednesday at a NASA briefing, aims to settle some big questions: Was there ever life on Mars? Is water there now? What are the weather cycles? The answers could lead to a better understanding of the environments of both Earth and Mars and pave the way for an eventual human journey to the Red Planet.
Though the United States and the Soviet Union sent earlier probes to Mars, the examinations ended in the 1970s and large gaps in scientists’ knowledge remain. One reason attention is turning to Mars now is the Bush Administration’s goal of sending astronauts there.
The nearly $900-million Mars Observer mission, managed by the Jet Propulsion Laboratory in Pasadena, will lay the groundwork by providing a global map of the planet’s rocky expanses, canyons, ancient shorelines, volcanoes and polar icecaps. The Observer will take images in detail fine enough to identify boulders 30 feet across--40 times higher resolution than any previous photos. The information will help the planners of future missions decide where to send landing craft, robots and perhaps, someday, humans.
Mars is “a planet that is alive and complex,” project scientist Arden Albee of Caltech said at the NASA news briefing in Washington. “We have explored it. Now we need to get a consistent set of data that will allow us to understand it.”
The Observer is scheduled for a Sept. 16 launch on a Titan III rocket from Cape Canaveral Air Force Station in Florida.
It is expected to begin mapping Mars in mid-December, 1993, said Wesley Huntress, director of NASA’s solar system exploration division. The craft--with an instrument platform about the size of an office desk--will stay in its near-polar orbit for a full Martian year, the equivalent of 687 Earth days. It will record changes over the course of four seasons.
The Observer’s instruments will scan Mars from 250 miles above the surface, completing an orbit every 118 minutes. Scientists plan to piece together the images to generate a daily weather map, much like Earth satellites provide for this planet.
Near the end of the Observer mission, scientists hope to cooperate with a 1994 Russian lander project, relaying data from the surface monitors to Earth. The Russians also want to launch a second lander in 1996 that would include a robot scout that could travel over boulders and up hills, as well as an instrument-laden balloon that would float along the surface. France, Germany and Hungary have contributed money and technology to the Russian missions.
NASA is working on a two-phase, 16-lander project, the Mars Environmental Survey. Several landers would be launched in 1996 and the rest in 1999. The survey may include a micro-rover, a tiny robot explorer.
The European Space Agency has been considering sending along its own mobile robot on one of the U.S. flights, according to Gordon Whitcomb, the agency’s head of future science projects. But money is tight and the robot is competing against other priorities, Whitcomb said.
The Japanese space agency is planning to launch in 1996 a craft that would probe Mars’ upper atmosphere and its relation to the solar wind, Observer deputy scientist Frank Pallucone said in an interview at JPL.
The feverish international activity may be the only way to gather detailed information about Mars, Pallucone said, because “the costs just prohibit one nation from doing it alone.”
The planet is now cold and dry, but some scientists theorize that early Mars was much like early Earth, with a thick carbon dioxide atmosphere that retained heat, and water running on the surface.
If so, “we should see remnants,” such as carbon ice, said Caltech’s Andrew Ingersoll, team leader of atmospheric and climate studies. Observer will look for water vapor, which would indicate large amounts of ice on the ground.
Evidence of an Earth-like past would lead scientists on an intense search for clues to what led to the transformation and for fossils of life forms.
The $500-million Observer craft also will look for evidence of climate cycles like the Ice Ages of Earth. “Earth has gone through radical climate changes in the past. We can’t observe those periods directly, so we go to other planets to get a broader perspective,” Ingersoll said.
“We can answer questions about the evolution of Earth by comparing it to Mars and Venus,” Albee added.
Other areas of investigation for Observer include the dust storms that occasionally blanket the planet, volcanic activity and the so-far-undetected magnetic field of Mars.
The strength of the Martian gravity field will be measured by continually tracking Observer and recording small differences in its speed.
Mission to Mars
The Mars Observer, scheduled for launch Sept. 16 from Cape Canaveral Air Force Station, will travel for 11 months before entering a near-polar orbit around the planet. A model of the craft is superimposed on a photo of Mars, above.
Background: Once it reaches Mars, the $500-million craft will stay in orbit for a full Martian year, the equivalent of 687 Earth days.
Aim: Mars Observer is to examine geological and atmospheric conditions and provide a detailed global map, which will help the planners of future missions decide where to send landing craft, robots and perhaps, eventually, human beings.
Overall Goal: The mission is the first of a string of ambitious probes planned over the next decade.
Scientists hope the cooperative ventures of the United States, Russia, Europe and Japan will answer some big questions: Did life ever exist on Mars? Is there water there now? What are the weather patterns there?
