The European Space Agency has finalized the contract to build key components of its BepiColombo spacecraft, designed to reach Mercury in 2019.

The agency said Friday that Astrium, Europe's largest space company, will build the spacecraft and the module that will carry the European and Japanese orbiters that will be doing the actual research.

An artist's rendering of BepiColombo leaving Earth on its six-year trip to Mercury.
(ESA-AOES Medialab)

The orbiters "will address scientific questions such as the origin and evolution of a planet close to its parent star, the status of the planet’s interior and of its magnetic field, as well as a test of Einstein’s theory of general relativity,” Johannes Benkhoff, European Space Agency (ESA) project scientist for BepiColombo, said in a release.

ESA’s Mercury orbiter will study the surface and internal composition of the planet while the Japanese Aerospace Exploration Agency's orbiter will study the magnetosphere, the region around the planet that is dominated by its magnetic field.

“Mercury has … regularly confounded planetary scientists with its exceptional properties, and that makes it a grand scientific challenge,” said David Southwood, the ESA's director of science.

BepiColombo is named after Giuseppe (Bepi) Colombo (1920-1984), an Italian scientist and mathematician whose calculations were key to the success of NASA's Mariner 10 Mercury mission.   

Mariner 10 was the first probe to reach Mercury 30 years ago. NASA's Messenger probe made the first of three scheduled passes of the planet on Jan. 14.

BepiColumbo is scheduled to launch in August 2013.

Mercury, the closest planet to the sun, measures less than half of Earth's diameter across and experiences temperature extremes as hot as 467 C on the side facing the sun and as cold as -170 C on the dark side.

BepiColombo will cost the ESA $999 million, with the instruments for the agency's orbiter running another $300 million.