Nasa is heading back to the Moon - on Friday.
The American space agency will launch its latest robotic lunar explorer atop a Minotaur V rocket from Virginia at 11.27PM Eastern time, or very early on Saturday in the UK.
The Lunar Atmosphere and Dust Environment Explorer (LADEE) will help Nasa look for signs that moon dust, which may have caused strange glows on the Lunar horizon reported by Apollo astronauts.
Above: The LADEE spacecraft in the nose-cone at the top of the full Minotaur V launch vehicle stack.
The small, human-sized craft also analyse the Moon's (very) thin atmosphere, and that in turn could teach scientists about other places in our solar system - including Mercury.
Ladee will take 25 days to get to the Moon, via a few loops around Earth and then a long rocket-powered journey across the trans-lunar 'ocean'.
Once in orbit it will spend 30 days checking systems, and then fire its rockets again to enter a new orbit which will let scientists gather data from 100 days before a controlled crash onto the surface.
Above: illustration of Ladee firing its rockets