SMART-1

Key facts

Mission & specifications

Mission

SMART-1 was a small, inexpensive European spacecraft built to prove a new way of travelling through space. Launched on 27 September 2003 as a piggyback passenger on an Ariane 5, the washing-machine-sized probe carried no conventional rocket for its cruise. Instead it used a solar-electric ion engine, which expelled xenon atoms at high speed to produce a gentle but continuous thrust. Rather than coasting on a quick trajectory, SMART-1 slowly spiralled outward from Earth over more than thirteen months, its faint exhaust patiently widening its orbit until the Moon's gravity captured it in November 2004. The technique used a tiny fraction of the propellant a chemical rocket would have needed, demonstrating efficient propulsion for future deep-space missions. Once in lunar orbit, SMART-1 mapped the surface in visible, infrared and X-ray light, surveying the distribution of minerals and searching for signs of ice in the polar craters, while testing miniaturised instruments and communications technologies. With its work done, the spacecraft was sent out in a controlled crash on 3 September 2006, striking the Lacus Excellentiae region at a shallow angle and throwing up a small flash that observers on Earth watched for. It was Europe's first mission to the Moon.

1. 2003Launch as an Ariane 5 passengerLaunch

   The small probe rides to space as a secondary payload, then lights its ion engine.

2. 2004Captured into lunar orbitArrival

   After spiralling outward for over thirteen months on ion thrust, it is caught by the Moon's gravity.

3. 2005Mapping the MoonMilestone

   Surveys surface minerals in visible, infrared and X-ray light and tests miniaturised instruments.

4. 2006Controlled impactMission end

   Out of mission, SMART-1 is crashed into Lacus Excellentiae, watched from Earth.

Images

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