Mission to land on a comet
Scientists are planning an ambitious mission to land a spacecraft on a comet travelling at 28,5000mph.
The European Space Agency aims to put the Rosetta mission into orbit around a comet called Wirtanen at the beginning of the next decade.
After final tests at the agency's laboratory in the Netherlands, the craft will be launched from Kourou, French Guiana, in 2003 - arriving at its destination on 28 November 2011.
A probe will then be released to land on the comet's head, a 700-metre-wide "dirty snowball" of frozen water, chemicals and dust. The orbiter will circle the comet at distances as close as 1.2 miles for 20 months.
To get there, the craft will first head for Mars, where it will use the gravitational pull of the planet to "slingshot" itself towards the comet.
The purpose of the mission is to glean answers to some of the fundamental questions about the universe - not just the formation of comets but of planets and the rest of the solar system.
The spacecraft was assembled in the Italian city of Turin before being transported to the European Space Research and Technology Centre at Noordwijk, Holland. Other lorries carried a mass of testing equipment.
The testing there, to be conducted in the next eight months, will simulate conditions that the spacecraft will experience in outer space - extreme temperatures, vibrations and an airless vacuum.
Dr John Ellwood, Rosetta's project manager, said: "These will ensure that it will be able to operate for many years in deep space, then complete its mission to Comet Wirtanen and deploy a lander on the icy nucleus."
