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NASA has fixed the orbit of its Mars Global Surveyor so that the probe can
spend the summer taking photographs of Martian scenery, including the
controversial 鈥淔ace on Mars鈥�, spotted by the Viking mission more than twenty
years ago. Other targets include the Mars Pathfinder and Viking lander sites.
The spacecraft鈥檚 elliptical 11.6-hour orbit ranges from 170 to 18 000 kilometres
above the surface, and takes it above each target about three times every month.
In September, NASA will begin to move the probe again to take it into close
circular orbit by March 1999.