After two weeks of manoeuvres started on 19 June and concluded on 2 July 2006, the impact is now set to occur on the near side and most probably at 05:41 UT (07:41 CEST) on 3 September 2006.


 
SMART-1 first orbits the Earth in ever-increasing ellipses. When it reaches the Moon, its orbit is altered by the Moon's gravitational field. It uses a number of these lunar 'gravity assist' manoeuvres to position itself for entering orbit around the Moon.


 
This artist's impression shows the location of the SMART-1 impact on the Moon surface, expected for 3 September 2006 at 07:41 CEST (05:41 UT), with an uncertainty of plus or minus 7 hours, due to the unknown lunar topography.

The expected coordinate for impact are 36.44º south of latitude and 46.25º west of longitude.. The impact site will be on the lunar area called ‘Lake of Excellence’, located at mid-southern latitudes. This area is very interesting from the scientific point of view. It is a volcanic plane area surrounded by highlands, but also characterised by ground heterogeneities.


 
When a spacecraft orbits around the Moon, as SMART-1 does, it is doomed by the law of gravity. Tugs from the Sun, the Earth, and irregularities in the Moon itself, all disturb its orbit. Sooner or later, any lunar orbiter will impact the Moon surface unless it has very big amounts of fuel left to be re-boosted and escape the lunar gravity.

By the time SMART-1 had settled into its operational orbit around the Moon in March 2005 its exeprimental ion engine had only 7 kilograms of propellant left (bottled xenon gas) out of the 84 kilograms available at launch. This fuel allowed orbital boosts, but was not sufficient for a Moon escape.

Last observations
 

 
This animation shows ESA's SMART-1 spacecraft making scientifc observations in orbit around the Moon. SMART-1 was launched in September 2003 and will conclude its mission through a small lunar impact on 3 September 2006.



Release date: 18 August 2006