Aug. 29, 2006 — After nearly two years circling the moon, a European robotic probe is wrapping up its mission while flight controllers prepare for a scientific grand finale: a crash onto the moon's surface this weekend.
SMART-1 was launched in September 2003 and reached the moon 14 months later for what was expected to be a six-month mission to test technologies for future robotic probes. The spacecraft, however, proved to be extremely robust, winning funding for two mission extensions.
In the end, the probe simply ran out of gas for its innovative solar-electric engine, one of several technologies tested on Europe's first Small Mission for Advanced Research in Technology (SMART) spacecraft.
It will be tugged out of orbit by lunar gravity late Saturday or early Sunday, crashing into a volcanic plain known as the Lake of Excellence, a fitting resting spot for a spacecraft that far surpassed scientists' expectations.
Using X-ray and infrared sensors, SMART-1 measured the chemical composition of the moon, adding evidence to theories that the moon was formed after a planet-sized object smashed into primordial Earth, said project scientist Bernard Foing, with the European Space Agency.
It also mapped the moon's impact craters and other geologic features to support future missions, he said.
The main point of the mission, however, was not science, but engineering. In addition to its new propulsion system, SMART-1 tested future deep-space communication techniques, autonomous navigation software and a suite of miniaturized scientific instruments.
"SMART-1 has been amazingly successful in proving new technologies that will help shape how Europe explores space in the future," said researcher Keith Mason, with the U.K.-based Particle Physics and Astronomy Research Council.
Flight controllers made a final series of maneuvers to position the probe so its crash onto the moon's surface would be detectable from Earth. Scientists using ground-based telescopes planned to scan the dust kicked up in the crash to detect chemicals in the lunar soil.
Foig said SMART-1 is a precursor for a fleet of international orbiters to be launched in 2007 and 2008 by China, Japan, India and the United States.
"We are studying concepts of lunar landers that could bring rovers to explore the poles and search for ice, or to prepare for a robotic village and human bases," he said.
