PASADENA, Calif. (UPI) - America's Viking 1 space robot landed gently on Mars today and radioed back the first pictures taken from the planet's surface -- "incredible" photos showing a sandy, rocky Martian desert with a gently rolling horizon.

The three-legged spacecraft rode a fusion of rocket exhaust to a gentle touchdown in a lowland considered one of the best places for its instruments to conduct the first search for life on the red planet.

The landing on the planet more than 200 million miles from earth opened a new frontier in man's exploration of the solar system. President Ford said in a telephone call to space agency officials the flight was "just wonderful and a most remarkable success."

The initial image from one of Viking's twin cameras started coming in at the control center at 8:55 a.m. EDT. The shot looked down and showed one of the Viking's footpads.

It was readily apparent that the Martian soil was littered with rocks. It appeared the soil had been blown by wind or thrust from Viking's landing rockets.

A few minutes later, after the camera raised its lens on command from a computer, a broad panoramic view of the landscape appeared line by line on control center monitors. It was late afternoon there and the setting sun appeared to brightly illuminate the distant sky.

There was no evidence of any life forms in the initial pictures. But scientists did not expect to see any.

Unlike pictures taken from the moon, the Martian surface did not appear pock marked with sharp craters. This apparently was the result of wind erosion on Mars. The planet has occasional dust storms and Viking was coated with a gray resilient paint to protect it from sand blast effects.

"This is just an incredible scene," said Dr. Thomas Much, geologist in charge of the photographic experiment. "It looks safe and very interesting."

"The resolution is just fantastic," Mutch said as he and hundreds of others at the Jet Propulsion Laboratory watched the image form on television monitors. "The detail is incredible."

Viking's descent to Mars was flawless. Engineers called out the various landing operations as they learned of them by radio reports from Mars and there was no hesitation when Viking landed.

"We have touchdown," exclaimed a Viking control spokesman at 8:12 a.m. EDT.

"Looking good," echoed engineers at the Jet Propulsion Laboratory seconds after touchdown. "Fantastic, beautiful," said one controller.

Engineers listened anxiously as word of Viking's parachute operation came in, followed by ignition of the landing rockets. There was a loud cheer in the control center when the first report of a safe landing reached the control center at 8:12 a.m. EDT - 18.8 minutes after the radio signals were transmitted from Viking.

Twenty-five seconds after touchdown, the 10-foot wide lander started taking the first picture. It was beamed to the still-orbiting section of Viking which radioed it back to Earth a few minutes later.

Mutch said it appeared Viking's long mechanical arm would have no difficulty scooping up soil for biology and chemical analysis experiments to be turned on later.

The footpad picture showed that Viking landed with minimum impact. The photo was so sharp rivets could be soon on the top of the aluminum foot with a shadow of higher apparatus.

It was the second landing on Mars of a spacecraft from Earth. Russia accomplished the feat in 1971 but its lander failed 20 seconds later without sending back useful data.

Viking 1 began the final leg of its 11-month journey from Earth 3 hours 21 minutes before touchdown when three explosive bolts holding the lander to its orbiting mother craft were detonated. At that point, Viking was 11,400 miles high, traveling at 3,040 miles per hour on its 29th orbit of Mars.

Eight small rockets then fired for 22 minutes to begin Viking's descent into the atmosphere. Viking sliced into the upper fringes of the Martian gases and temperatures as high as 2,730 degrees Fahrenheit built up outside a saucer-like heat shield.

Viking's descent at that point was very shallow, allowing atmospheric drag to slow the craft enough so a 53-foot wide parachute could be deployed 19,000 feet high.

Acting on commands from its onboard computers, Viking then jettisoned its protective shell and a few seconds later unfolded its three landing legs.

Less than a mile above mars, and guided by four radar beams, Viking jettisoned its parachute and three powerful landing rockets fired. This slowed the spacecraft so it dropped to Mars traveling about 5 1/2 mph - an impact similar to what one would feel jumping off a table on Earth.

Mars gravity accelerated the lander to as much as 10,000 mpg as it neared the planet. When it hit the thicker parts of the "air," engineers reported the craft was feeling acceleration forces eight times the force of earth gravity.