The BepiColombo Mission to Mercury is sponsored by the European Space Agency (ESA) and the Italian Space Agency (ASI), but that expedition will soon be joined by NASA .
Announced June 20 in Rome by NASA administrator Charles Bolden and Enrico Saggese, president of ASI, this announcement paves the way for NASA to take part in the joint European/Italian mission to the innermost planet. The American contribution to the BepiColombo expedition will be an instrument called Strofio. This device will measure the extremely thin atmosphere surrounding Mercury.
The Bepicolombo mission will consist of a pair of orbiters. The first, the Mercury Planetary Orbiter (MPO) will serve as an orbiting observatory. The second craft, the Mercury Magnetospheric Orbiter (MMO), will map the planet in multiple wavelengths of light. The MMO will also be able to determine if Mercury has a molten core and chart the distribution of minerals across the planet's surface.
Total costs of the BepiColombo mission are estimated at around one billion dollars, with the Strofio instrument costing about $32 million dollars.
BepiColombo will be the first time that the European Space Agency has sent a mission this close to the Sun. All previous interplanetary missions from the agency have been to colder worlds.
The Japanese Aerospace Exploration Agency (JAXA) is building the Mercury Magnetospheric Orbiter (MMO). Both orbiters will launch together on top of an Ariane 5 rocket, due for takeoff in August 2015, with arrival at their destination scheduled for 2022.
Launching orbiters to Mercury presents special challenges, as the gravity of the Sun has a significant effect at that distance, pulling the craft toward our home star. Only two spacecraft have successfully explored the tiny planet at close range, the first being Mariner 10, which launched November 3, 1973. NASA is currently operating the MESSENGER orbiter at Mercury, which among other findings, has discovered that the surface of the planet is swelling.
After launch, the craft will gather energy by slingshoting around the Earth one time, then twice around Venus, then around Mercury four times. The pair of craft will then settle into steady orbits for the study of the innermost planet. All in all, the journey from Earth to Mercury will take around six years, given the roundabout route by which the craft will travel to the smallest planet orbiting our Sun.
Using planets to redirect spacecraft is nothing new, but the process was studied in detail by Italian scientist and engineer Guiseppe "Bepi" Colombo, after whom the mission is named. Colombo passed away in 1984.
Saggese also expressed Italy's support for joining NASA for missions to asteroids, and other planetary bodies in our solar system.