NASA announced that it will be participating in the joint European-Japanese BepiColombo space mission that will be sending two spacecraft to study Mercury.

NASA Administrator Charles Bolden and Italian Space Agency (ASI) President Enrico Saggese signed a Memorandum of Understanding Thursday, June 20. The two also discussed future plans for exploring an asteroid.

NASA is expected to contribute an instrument known as Strofio, which can measure the pockets of gas surrounding our solar system's innermost planet. A NASA spokesperson in a Discovery News report states that NASA's involvement in the $1 billion BepiColombo mission rounds out to approximately $32 million.

BepiColombo is a two spacecraft mission led by the European Space Agency (ESA) and the Japanese Aerospace Exploration Agency. The spacecraft, one Mercury Planetary Orbiter (MPO) and one Mercury Magnetospheric Orbiter (MMO), are slated to blast off in 2015 and then expected to arrive at Mercury in 2022.

"One of ESA's cornerstone missions, it will study and understand the composition, geophysics, atmosphere, magnetosphere and history of Mercury, the least explored planet in the inner Solar System," reads the BepiColombo official webpage under the section detailing the objective of the project.

Only two spacecraft have visited Mercury before: NASA's Mariner 10 and Messenger. Studying the planet is hard because of its proximity to the sun, whose brightness makes observation from Earth rather difficult. For the MPO and MMO, not only will temperatures be incredibly hot (most missions tend to move away from the sun, into the colder regions of space), the sun's gravity will be exerting a tremendous amount of force.

Both MPO and MMO will launch off as a single unit, which will travel to Mercury with the help of planets' gravitational pulls. Once there, the MPO and MMO will separate into their respective orbits, and begin a detailed analysis of the "least-explored planet in the inner solar system," according to the ESA.