U.S. Launches A Spacecraft On a Mars Trip
By JOHN NOBLE WILFORD
Published: September 26, 1992
The first American spacecraft bound for Mars in 17 years was launched yesterday on a planned 11-month, 450-million-mile voyage to map the planet, explore its geological and climatological history and look for evidence that life might have once existed there.
After a successful liftoff at the Cape Canaveral Air Force Station in Florida, the 5,700-pound Mars Observer spacecraft was cruising on course for a rendezvous with the red planet next Aug. 24.
"The spacecraft is healthy and on the proper trajectory for Mars," said Jim Doyle, a spokesman for the Jet Propulsion Laboratory in Pasadena, Calif., which is directing the $900 million mission for the National Aeronautics and Space Administration.
When the spacecraft arrives at Mars, it is to swing into an orbit crossing the planet's poles and spend at least one full Martian year -- 687 Earth days -- photographing the windswept plains, volcanic peaks, yawning canyons and dry river channels in unsurpassed detail. Scientists expect the mission to produce more data about Mars than all previous spacecraft that reached the planet, including the two Vikings that landed there in 1976 and failed to find any signs of present life in the soil. Hope for More Exploration
Scientists and space agency officials hope the mission will prepare the way for a robust revival of Mars exploration in the next decade and the eventual flight of humans to the planet's cold, dry but alluring landscape.
Liftoff came at 1:05 P.M., a delay of 38 minutes while technicians grappled with last-minute preparations and mission officials anxiously monitored blustery winds in the launching area. After the Titan 3 rocket powered the spacecraft into an orbit of Earth, there was even more suspense, as flight controllers had to wait for more than an hour to get confirmation that another rocket firing had succeeded in sending Mars Observer on its interplanetary trajectory.
The suspense was heightened because this critical maneuver depended on the performance of a solid-fuel upper-stage booster, called a transfer orbit stage, that was making its flight debut. For some undetermined reason, data confirming the ignition did not arrive as scheduled.
Finally, when Mars Observer transmitted signals to a tracking station in Australia, flight controllers could relax. "The spacecraft has phoned home," said a jubilant Dr. Bevan French, NASA's chief scientist for the program.
From the tracking data, engineers could tell that the upper-stage booster had fired properly to propel the spacecraft out of Earth's gravitational grip and on its way to Mars at an initial speed of 37,500 miles an hour. Engineers also reported that a sun sensor used for aligning the spacecraft had failed to operate properly, but a backup sensor had been switched on.
"I'm not really concerned," said David D. Evans, the project manager at the Jet Propulsion Laboratory. Sharper Photos Sought
The spacecraft was built by the Astro-Space division of the General Electric Company at Princeton, N.J. The Titan 3 rocket was built by the Martin Marietta Corporation in Denver, and the transfer orbit stage was assembled by Martin Marietta under contract to the Orbital Sciences Corporation in Vienna, Va.
Mars Observer is equipped with wide-angle and narrow-angle cameras for taking pictures that could be 40 times sharper than any previous photography of the planet, showing objects as small as 10 feet across. Other remote-sensing instruments on board are designed to determine the mineral content of the Martian surface, temperatures and weather conditions, magnetic fields and the elevations of topographic features.
One of the spacecraft's objectives is to investigate the presence of water on Mars. Some is frozen at the poles, and scientists say there is indirect evidence that a large volume of water lies frozen beneath the Martian plains in the form of permafrost. Where there is water now, scientists reason, would be the most promising places for setting up human encampments and for searching for any signs of microorganisms.
Even if there is very little water on Mars now, all the photographic evidence of eroded valleys and dry river channels suggests to scientists that floods of water washed across the planet in its early history. And if there was considerable liquid water on Mars at one time, scientists speculate, life could have evolved briefly and might have left some fossil remains.
Photo: The Mars Observer, the first American spacecraft bound for Mars in 17 years, as it was launched yesterday at Cape Canaveral, Fla. (gence France-Presse)