Japan, Europe send spacecraft on 7-year journey to Mercury


By improving our understanding Mercury's composition, atmosphere, and magnetism, scientists can better understand how rocky-Earth-like planets came to be - and provide insight into whether other far-off solar systems may have formed similar planets.

The $1.9 billion BepiColombo project is only the second, after NASA's MESSENGER mission, to attempt putting a spacecraft into orbit around the innermost planet, one of the most technically challenging missions ever attempted by the European Space Agency and the Japanese Aerospace Exploration Agency, or JAXA. (It spins on its axis three times for every two orbits around the sun).

The BepiColombo spacecraft will have to follow an elliptical path that involves a fly-by of Earth, two of Venus and six of Mercury itself so it can slow down sufficiently before arriving at its destination in December 2025.

"(Mercury is) the planet that helped us prove that relativity is real, the planet that is astonishingly hot on its sun-side and yet carries ice in craters at its North Pole", Bill Nye, CEO of the Planetary Society, said in a statement. The tiniest planet in the solar system, Mercury is relatively unstudied and probably holds many mysteries. Even if BepiColombo only partially fulfills its objectives, the knowledge that researchers gained in designing and launching the spacecraft will be applied to future missions. A big challenge is that the Sun's gravity is huge, which makes it tricky to put a spacecraft into Mercury's orbit. Activities will include measuring the planet's interior structure, studying surface features and watching how the planet's magnetic field interacts with the flow of charged particles that constantly streams off the sun. Eastern, marking the beginning of a 9-billion kilometer trip to the closest planet to the Sun. "A collision with the proto-Earth or proto-Venus could be what robbed it of so much of its original rock". It helps tell us a little bit more about the Earth's origin story.

Mercury is the smallest and least explored planet in the inner Solar System - having only been examined by Nasa's 1974 Mariner probe and 2004 Messenger mission. The first spacecraft to visit Mercury was NASA's Mariner 10 that flew past the planet in the mid-1970s.

BepiColombo's arrival will undoubtedly bring new information to light.

The other half of BepiColombo's science mission will be conducted by the Mercury Magnetospheric Orbiter, provided by JAXA and nicknamed Mio.

Key elements of ESAs Mercury Planet Orbiter were also assembled by Airbus in the UK.

BepiColombo is created to endure Mercury's harsh environment, including the glare of solar radiation and temperatures that swing between 840 degrees Fahrenheit on the planet's sunlit side and 300 degrees below zero on the dark side.

They will be used not to accelerate the craft but to act as a brake against the sun's enormous gravity.

The BepiColombo spacecraft is due to be launched from the European space port at Kourou in French Guiana, at around 2.45am tomorrow morning. Pacific Time on Friday (10:45 p.m. local time).