CAPE KENNEDY -- Mariner 9 raced two distant Russian probes toward Mars today to orbit the planet, map its battered surface and search from its icy poles to dusty equator for clues of life.
The American spacecraft trailed the farthest Soviet craft by more than 1 million miles, but still was given a chance of reaching Mars first. Officials called the accuracy of Mariner's course "fantastic."
Mariner 9 is scheduled to brake into orbit around Mars Nov. 14. It carries two television cameras and other instruments to survey two-thirds of the Martian surface, analyze its thin atmosphere and look for low, warm and damp spots that might shelter primitive forms of life.
Soviet commentators have hinted Russia's heavy Mars 2 and Mars 3 spacecraft might land on Mars with biological sensors. Mariner will not be able able to detect living things from orbit, but may turn up evidence indicating the existence of extraterrestrial life.
Of particular interest to scientists is a mysterious "wave of darkening" suggestive of vegetation moving with the seasons. Mariner 9 is designed to operate in Mars orbit for at least three months to watch for seasonal changes.
The 2,200-pound, $65 million spacecraft was launched yesterday. It performed one important maneuver after another before settling down for its curving, 247-million mile interplanetary voyage.
Mariner 9 was operating on its own today, using the bright star Canopus as a celestial reference point along with the sun and the shrinking earth. A central computer that can be cued from earth controlled routine operations.
"It appears as though we have a very successful and promising mission for Mariner 9," said a spokesman at the Mariner control center at the jet propulsion laboratory, Pasadena, Calif. "The spacecraft behavior is completely normal."
Still ahead is an important course correction scheduled Saturday. It will compensate for a deliberate trajectory error programmed into Mariner's rocket to eliminate the possibility that the probe or rocket would hit and contaminate Mars.
The Atlas-Centaur rocket that launched Mariner 9 was identical to the one that carried Mariner 8 to destruction May 8. But it worked smoothly yesterday, accelerating Mariner 9 to 24,500 miles per hour in 13 minutes to break earth's; gravitational grip.
Dr. George M. Low, deputy space agency administrator, said Mariner 9's mission ranked second only to Apollo moonflights in importance to the agency this year. It marked the beginning of a planetary exploration program covering all eight other planets in 10 years.