First European moon mission to crash-land in Excellence

EUROPE’S first mission to the moon is due to crash- land in a cloud of dust and rock Sunday, ending a three-year voyage that gathered data about the lunar surface and tested a new engine intended to propel future spacecraft to Mercury and other planets.

The European Space Agency’s SMART-1 should hit its target on a volcanic plain called the Lake of Excellence at 5:41am Irish time, skimming low as it makes its final approach at 4,475 mph.

Observatories on earth will try to capture images of the impact and the resulting debris cloud, and European space officials hope their study of the debris will provide information about the minerals present at the impact site.

Even before the mission ends, however, ESA is already celebrating the main goal — a successful test of the ion engine they hope to use for future interplanetary missions, such as the BepiColombo joint mission to Mercury with Japan’s space agency which is due for launch in 2013.

“The prime object of this mission was to test the ion propulsion,” mission manager Gerhard Schwehm told the Associated Press.

“This is a very efficient means to get a spacecraft over large distances with a very small mass of fuel. It worked really well.”

Instead of burning rocket fuel, the PPS-1350 engine from French aerospace firm Snecma generates a stream of electrically charged atoms called ions. That creates minuscule amounts of thrust — roughly enough to hold up a postcard.

Riding that small, steady push, SMART-1 made it to the moon in 14 months, gradually accelerating and raising its orbit around the earth until it was high enough to be grabbed by the moon’s gravity.

It was launched into Earth orbit using an Ariane-5 rocket from the European spaceport in Kourou, French Guinea, on September 27, 2003.

By contrast, the first manned US moon mission, Apollo 11, took 76 hours to reach lunar orbit in 1969, with a Saturn V rocket.

SMART-1, a cube measuring roughly a yard on each side, took the long way — over 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 and on only 176 pounds of xenon fuel.

NASA’s Deep Space 1, launched in 1998, also used an ion engine.