A dishwasher-sized spacecraft on Europe's first mission to the moon was set to enter lunar orbit tonight, a key milestone in its 13 month trip into space.
The SMART-1 probe was to begin circling the moon sometime overnight in a new phase after spiralling around the Earth for more than a year, according to European Space Agency spokesman Mr Franco Bonacina in Paris.
The spacecraft is expected to explore the moon's surface for at least six months, looking for water and helping scientists study the idea of building a permanent base on the lunar surface.
The probe is to begin examining the moonscape in January.
The SMART-1, billed as a test bed for fuel efficient technologies, is carrying only 76 pounds of xenon fuel. More traditional rockets can require tons of fuel.
"This is a sort of test for ion propulsion," said Bonacina. "It has the potential to be used for longer missions in the future - to travel to other planets, for example."
Though other methods of propulsion are faster for relatively short distances - such as from Earth to the moon - ion propulsion should prove to be faster for longer missions, he said.
PA