What is BepiColombo Mission (European Space Agency)| To planet Mercury

BepiColombo mission was launched on 20 October 2018 at 1:45 UTC through rocket named Ariane 5 ECA from Guiana space center.
This is the joint mission of European space agency (ESA) & Japan space exploration agency (JAXA) to study about the planet Mercury. It was approved in the year 2009 but with all planning & other factors it was launched in 2018. This mission was the last mission of ESA's Horizon 2000+ program. The launch mass of rocket at launch was 4100 Kg & dry mass was 2700 Kg. It will reach mercury on December 2025(expected).

OBJECTIVES OF THE MISSION 

The main objectives of the BepiColombo mission are as follows:

1. To find out the reason for mercury's higher density.
2. To know more about geographical structure of the planet like whether the surface is solid, liquid or gaseous.
3. How mercury has such great magnetic field ?
4. If there is no presence of ionosphere how it deals with the sun's solar winds.
5. To observe unseen hemispheres of mercury.
6. If iron element is the major constituent of planet, why spectroscopic observations doesn't reveal it ?
7. Is the planet still volcanically active ?
   
8. To test or verify Einstein's general theory of relativity by considering the advancement of mercury's perihelion over time.
9. If mercury is said to have water on it's surface in the form of ice then this mission will find out whether that ice is pure or mixed with some elements, it will also try to gather information about these elements?

   

   Temperature map of north region of mercury blue shows temperature which is very low in the craters, red shows high temperature on the surface.

COMPONENTS OF THE MISSION

BepiColombo comprises of two main satellites named Mercury Planet Orbiter (MPO) & Mercury Magnetospheric Orbiter ( MMO).

MERCURY PLANET ORBITER ( MPO)

MPO

MPO is ESA's contribution to this mission, with it ESA has also built Mercury Transfer Module (MTM), sunshield & interface strucutre ( MOSIF) to provide thermal protection to MMO about which i will we discussing later.

MECHANICAL & THERMAL DESIGN

MPO is designed to meet needs of payloads when spacecraft is in operational orbits. Payloads are present below spacecraft with instruments & sensors at the main radiator. The location of other instruments is as follows: 

1. MERTIS & PHEBUS are located near the radiator to provide calibration & rotational field of view.
2. SIMBIO-SYS sensors & BELA optical head are located at a highly stable optical bench with star trackers & gyroscope to provide pointing performance.
3. ISA is located near the center of mass of spacecraft.
4. MERMAG sensors are located on 3.2 m deployable boom.

MPO uses double H configuration to harmonize with single radiator plane. Heat from instruments & from sun will be carried to the main radiator using embedded heat pipes in the spacecraft.

POWER GENERATION 

A solar array on single side is present with Optical Solar Reflectors ( OSRS). Solar array will be continuously rotated to keep sun at a low incidence angle to generate adequate power for the spacecraft. Direction will be optimised to overcome natural & artificial eclipses, during eclipses spacecraft will get power from the batteries to avoid interruption in the ongoing processes.

COMMUNICATION

It comprises of two fixed low gain antenna (LGA), a steerable medium gain antenna (MGA) & a steerable one meter diameter high gain antenna.

LGA will provide coverage at small distances from earth, MGA will provide coverage at interplanetary cruise phase. HGA will provide X-band up link & Ka- band down link for science operations of spacecraft.

The MPO will travel around mercury in a planar orbit with a time period of 2.3 hours & orbit will be co planar with MMO.

INSTRUMENTS INCLUDED:

1. BELA- BepiColombo Laser Altimeter.
2. ISA- Italian Spring Accelerometer.
3. MAG- Magnetic Field Measurement.
4. MERTIS- Mercury Radiometer & Thermal Imaging Spectrometer.
5. MGNS- Mercury Gamma ray & Neutron Spectrometer.
6. MIXS- Mercury Imaging X-ray Spectrometer.
7. MORE- Mercury Orbiter Radio Science Experiment.
8. PHEBUS- Probing of Hermian Exposure by Ultraviolet Spectroscopy.
9. SERENA- Search for Exosphere Refilling & Emiited Natural Abundances( neutral & ionised particle analyser).
10. SIMBIO-SYS- Spectrometers & Imagers for BepiColombo Intergarted Observatory.
11. SIXS- Solar Integrated X-ray & particle spectrometer.

MERCURY MAGNETOSPHERIC ORBITER

MMO

MMO is provided by Institute of Space & Aeronautical Science (ISAS) & JAXA.

DESIGN

The structure of MMO is like octagonal prism, which is 1.8 meter between the opposing planes & of 0.9 meter height. The total mass of MMO is 275 Kg & the mass of instruments included in MMO is 45 Kg.

Instruments are mounted on the exterior of top & bottom panels, are also shielded from sun by walls of the planes. Each of the eight planes consists of solar cells & average power generated will be around 350 Watts.

MMO is also spin stabilised with a rotation rate of 15 RPM & a spin axis i.e almost perpendicular to the orbital plane of mercury. Centrifugal effect of spin will enable the deployment of four 15 meter long wire antennas for electric field & radio wave measurements.  It is also having two 5 meter long masts to provide a suitable environment for magnetic field measurements.

MMO will travel mercury in a polar orbit with a orbit of 9.5 hours. It's orbit will be co-planar with orbital period of MPO as mentioned above which is 2.3 hours.

INSRUMENTS INCLUDED:

1. MGF- Mercury Magnetometer.
2. MPPE- Mercury Plasma Particle Experiment.
3. PWI- Mercury Plasma Wave Instrument.
4. MSASI- Mercury Sodium Atmospheric Spectral Imager.
5. MDM- Mercury Dust Monitor.

PRESENT STATUS OF BEPICOLOMBO

To know more about the current situation of BepiColombo mission you can visit the link given down below:

https://www.cosmos.esa.int/web/bepicolombo

Peace☮