ESA gives go-ahead to build BepiColombo

BepiColombo is the next European planetary exploration project, and will be implemented in collaboration with Japan. A satellite 'duo' - consisting of an orbiter for planetary investigation and one for magnetospheric studies - will reach Mercury after a six-year journey towards the inner Solar System, to eventually perform the most extensive and detailed study of the planet ever performed so far.
The 'Mercury Planetary Orbiter' (MPO) will be under ESA responsibility, while the Mercury Magnetospheric Orbiter (MMO) will be under the responsibility of the Japan Aerospace Exploration Agency (JAXA). The Mercury Transfer Module (MTM), also under ESA responsibility, will provide the electrical and chemical propulsion required to perform the cruise to Mercury. These three modules assembled together for the launch and cruise phase make up a single composite spacecraft.

The MPO will carry a highly sophisticated suite of eleven scientific instruments, ten of which will be provided by Principal Investigators through national funding by ESA Member States and one from Russia.

The MMO will carry five advanced scientific experiments that will also be provided by nationally funded Principal investigators, one European and four from Japan. Significant European contributions are also provided to the Japanese instruments.

After a competitive definition phase started in 2001, ESA is now ready to award Astrium GmbH (Friedrichshafen, Germany) with the prime contract for the BepiColombo implementation phase, consisting of the mission design and of the design, development and integration of the 'cruise-composite' spacecraft. Astrium GmbH will also provide engineering support to the launch campaign and the in-orbit commissioning phase.

Reaching Mercury and placing a spacecraft in a stable orbit around it is a difficult task due to the gravity of the Sun. BepiColombo will reach the planet - visited only by NASA's Mariner 10 in the mid seventies - in a truly novel way.

Image Credit: ESA - C.Carreau
High resolution image (1.1 MB)

This artist's impression shows ESA's BepiColombo's Mercury Planetary Orbiter (MPO) that, together with a second spacecraft, the Japanese Mercury Magnetospheric Orbiter (MMO), makes the BepiColombo mission at Mercury.

The MPO will study the planet itself and, among several investigations, it will make a complete map of Mercury at different wavelengths. It will also map the planet's mineralogy and elemental composition and determine whether the interior of the planet is molten or not.



Image Credit: ESA - C.Carreau
High resolution image (1.1 MB)

This artist's view shows the two BepiColombo orbiters (MPO and MMO) mounted on top of their transfer module (cruise configuration).

For its journey to destination BepiColombo will cleverly use the gravity of the Moon, Earth, Venus and Mercury itself in combination with the thrust provided by solar-electric propulsion (SEP). During the voyage to Mercury, the two orbiters and transfer module, consisting of solar-electric propulsion and chemical propulsion units, will form one single composite spacecraft.

Once approaching Mercury, the transfer module will be separated and the composite spacecraft will use conventional rocket engines and the so-called 'weak stability boundary capture technique' to bring it into polar orbit around the planet. When the MMO orbit is reached, the MPO will separate and lower its altitude by means of chemical propulsion to its operational orbit. Scientific investigations will go on for at least one Earth year.




Image Credit: ESA - C.Carreau
High resolution image (1.1 MB)

This artist's impression provides a view of the two BepiColombo spacecraft, the Mercury Planetary Orbiter (MPO) and the Mercury Magnetospheric Orbiter (MMO), in their elliptical, polar orbits around Mercury.

The MPO will circle the planet along an orbit ranging between 400 and 1500 kilometres distance from the surface. The MMO orbit ranges between 400 and 12000 kilometres from the surface. The inclination and the eccentricity of these orbits are optimised for the study of the planet and of its magnetosphere in the very-high-temperature environment around Mercury.




Image Credit: EADS Astrium
High resolution image

This exploded view shows BepiColombo in its cruise configuration. Visible from the bottom are: the BepiColombo transfer module, the Mercury Planetary Orbit (MPO), the sun shield and the Mercury Magnetospheric Orbiter (MMO).

The transfer module is provided with solar-electric propulsion and chemical propulsion units. The former will be used during the cruise to destination; the latter will be used after launch to boost up the orbit to the Moon's altitude for the planned lunar gravity-assist.

During the cruise, the mission will make clever use of the gravity of the Moon, Earth, Venus and Mercury itself in combination with the thrust provided by solar-electric propulsion. This innovative combination of low thrust space propulsion and gravity assist has been demonstrated by ESA's technology mission, SMART-1.

When approaching Mercury, the transfer module will be separated and the two-spacecraft composite will use conventional rocket engines and the so-called 'weak stability boundary capture technique' to bring it into polar orbit around the planet. When the MMO orbit is reached, the MPO will separate and lower its altitude by means of chemical propulsion to its operational orbit. Observations from orbit will go on for at least one Earth year.

Operating a spacecraft in the harsh environment of Mercury represents a true technological challenge. Mercury is the closest planet to the Sun, and the direct solar radiation hitting the spacecraft is about ten times more intense than in Earth's proximity.

Furthermore Mercury's surface, whose temperature can reach up to 470°C, not only reflects solar radiation but also emits thermal infrared radiation. Therefore, the probe will have to withstand extreme thermal conditions.

This will be one of the driving factors in the probe's design - for instance, it will drive the design of the multi-layer blanket to insulate the spacecraft and of its heat radiators.

European Space Agency News Release