DARMSTADT, Germany – Europe's first spacecraft to the moon ended its three-year mission Sunday with a planned crash, hitting its target after ground controllers had to maneuver it around a looming crater rim.
The SMART-1 spacecraft slammed into volcanic plain called the Lake of Excellence at 1 1/4 miles per second right on time. The impact was captured by observers on Earth, and scientists hoped the resulting cloud of dust and debris would provide clues to the geologic composition of the site.
"That's it -- we are in the Lake of Excellence," said spacecraft operations chief Octavio Camino as applause broke out in the European Space Agency's mission control center in Darmstadt, Germany. "We have landed."
Minutes later, a video screen on the control room wall showed an image of the bright flash from the impact. The infrared image was captured by the Canada France Hawaii Telescope on Mount Kea, in Hawaii.
"It was a great mission and a great success and now it's over," said mission manager Gerhard Schwehm.
During its months in orbit around the moon, the spacecraft scanned the lunar surface from orbit and took high-resolution pictures. But its primary mission was testing a new, efficient, ion propulsion system that officials hope to use on future interplanetary missions, including the BepiColombo mission to Mercury slated for 2013.
SMART-1 was launched into Earth's orbit by an Ariane-5 booster rocket from Kourou, French Guiana, in September 2003. It used its ion engine to slowly raise its orbit over 14 months until the moon's gravity grabbed it.
The engine, which uses electricity from the craft's solar panels to produce a stream of charged particles called ions, generates only small amounts of thrust but only needed 176 pounds of xenon fuel.
The craft's X-ray and infrared spectrometers have gathered information about the moon's geology that scientists hope will advance their knowledge about how the moon's surface evolved and test theories about how the moon came into being.
On Saturday, mission controllers had to raise the craft's orbit by 2,000 feet to avoid hitting a crater rim on final approach. Had the orbit not been raised the craft would have crashed one orbit too soon, making the impact difficult or impossible to observe.
The maneuver had to be carried out quickly in the early hours of Saturday, and operations chief Camino acknowledged that "we were under some stress."
SMART-1, a cube measuring roughly a yard on each side, took the long way to the moon -- more than 62 million miles instead of the direct route of 217,000 to 250,000 miles. But ESA did it for a relatively cheap $140 million.
The spacecraft also been taking high-resolution pictures of the surface with a miniaturized camera, sending back its last close-up images just minutes before the impact.