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BepiColombo mission |
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BepiColombo mission |
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The spacecraft which have arrived at Mercury is only Mariner 10, three flybys in 1974-5.
The trajectory of these flybys was proposed by the Italian scientist Guiseppe(Bepi) Colombo (1920-1984).
He is also known by the study of the secret that
the period of rotation (58 days) and the cycle of revolution round the sun (88 days) of Mercury
have the relation of 2:3 correctly.
"BepiColombo" project, named after him by ESA,
is the first large-sized Europe-Japan joint mission.
This mission consists of two orbiters and
aims the interdisciplenary and comprehensive studies of Mercury,
including the magnetic field, the magnetosphere, the interior, and the surface.
- Mercury Planetary Orbiter (MPO)
The 3-axis stabilized spacecraft provided from ESA.
It studies geology, composition, inner structure, and exosphere.
- Mercury Magnetospheric Orbiter (MMO)
The spin stabilized spacecraft provided from JAXA.
It studies magnetic field, atmosphere, Magnetosphere, and inner interplanetary space.
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Road to Mercury |
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They are combined with
Solar Electric Propulsion Module (SEPM: provided from ESA), and
Chemical Propulsion Module (CPM: provided from ESA).
The Unified module will be launched with Ariane 5 rocket, and travel together to Mercury.
Launch time aims 2013, in the plan at 2006 Feb.
In the interplanetary space, the unified module is promoted by the SEPM which makes "small but steady/continuous"
propulsion, associated with swingbys with the Moon, Venus, and Mercury.
Just before the arrival to Mercury, SEPM will be separated.
After that, the Unified module will make rapid slow-down by the CPM,
and go into "the MMO orbit" around the Mercury.
MMO will be separated at this stage, and begin the independent operation.
And the CPM will make the second propulsion for lowering the orbit.
And finally, the MPO is separated.
Both spacecraft will make observation of 1 earth year (4 Mercury years).
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Mercury: Technical Challenge
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In order to realize the Mercury orbiters,
we have to solve some technical difficulties.
Especially difficult things are:
- Mercury has greatly different revolution speed compared to Earth. And its mass is small.
For those reason, the Mercury orbiter requires a high thrust.
- At Mercury, the sunlight is 11 times larger than at Earth in maximum.
Moreover, since the surface temperature of Mercury reaches a maximum of 700 K
(Lead melts!),
infrared radiation from the surface is also large.
For those reason, the anti-thermal techniques
which does not have an example in the past space project are essential.
These problems are being conquered by technical development in recent years.
The former was solved by the electric propulsion system
(the asteroid probe HAYABUSA is also used).
The latter is also solved by the "mirrors" on the spacecraft surface, etc.
There are several gateways for the travel to Mercury;
the success of the launch, long cruising,
several flybys with Moon, Venus, and Mercury,
precise velocity controls,
super-long distance communications,
in the environment different from the one around the Earth.
Development of the spacecraft is now on going
based on the experiences of the past missions including ISAS/JAXA
Geotail (Magnetospheric probe) /
Nozomi (Mars orbiter) /
HAYABUSA (Asteroid probe) and ESA
Cluster (Magnetospheric multi probes) /
Mars Express (Mars observer) /
Rosetta (Comet probe).
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Messenger mission: Competition and Collaboration |
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As other Mercury program, there is
MESSENGER
which have been adopted as one of the
Discovery programs of
NASA (USA).
MESSENGER was launched in 2004, and will be arrived at Mercury after seven years travel,
and observe Mercury in 1 earth year.
Because of the inclination of the orbit and the limitation of the field of view of the instruments,
investigations for Magnetosphere or the internal structure of Mercury is difficult by MESSENGER.
But, it will make the first surveys of the geology and composition
on all surfaces of Mercury, and also observe Northern Hemisphere in detail.
Discovery of MESSENGER means the appearance of new observation targets for BepiColombo.
BepiColombo will complete the intensive study of Mercury begun with the exploration by MESSENGER.
Synergistic strategies of exploration will enable efficient use of BepiColombo resources
in a more detailed studies of Mercury.
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BepiColombo mission: Spacecraft
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Spacecraft
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Development
Operation
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European Space Agency (ESA)
- Development: ESTEC [European Space Research & Technology Center]
- Operation: ESOC [European Space Operation Center]
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Institute of Space and Astronautical Science (ISAS)
Japan Space Exploration Agency (JAXA)
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Objectives
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Geology, Composition,
Interior, and Magnetic field
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Magnetic field, Magnetosphere,
Atmosphere, Interplanetary Space
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Mass(TBD)
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Total: ~360kg, Payload: ~60kg
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Total: ~220kg, Payload: ~40kg
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Science Teams
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[Altimeter]
BELA (Laser Altimeter)
[Radio Science]
ISA (Accelerometer), MORE (Ka-band trans.)
[Magnetic field]
MERMAG (Magnetometer)
[Image & V-NIR Spectrum]
SIMBIO-SYS
[IR]
MERTIS-TIS
[Gamma and neutron]
MGNS
[X-ray]
MIXS (spectrometer), SIXS (Solar monitor)
[UV]
PHEBUS (spectrometer)
[Neutral / Ion particles]
SERENA
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[MGF: Magnetic Field Investigation] (2 sub-teams)
studies magnetic field from the planet, magnetosphere, and
interplanetary solar wind.
[MPPE - Mercury Plasma Particle Experiment] (7 sub-teams)
studies plasma & neutral particles from the planet, magnetosphere,
and interplanetary solar wind.
[PWI - Plasma Wave Investigation] (7 sub-instruments)
studies electric field, electromagnetic waves, and radio waves from
magnetosphere and solar wind.
[MSASI - Sodium Atmosphere Spectral Imager]
studies thin sodium atmosphere of Mercury.
[MDM - Mercury Dust Monitor]
studies dust from the planet and interplanetary & interstellar space.
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Orbit (TBD)
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MPO: 400km× 1500km, Polar orbit
MMO: 400km×12000km, Polar orbit
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