Home      Discussion      Topics      Dictionary      Almanac
Signup       Login
BepiColombo

BepiColombo

Discussion
Ask a question about 'BepiColombo'
Start a new discussion about 'BepiColombo'
Answer questions from other users
Full Discussion Forum
 
Encyclopedia
BepiColombo is a joint mission of the European Space Agency
European Space Agency
The European Space Agency , established in 1975, is an intergovernmental organisation dedicated to the exploration of space, currently with 18 member states...

 (ESA) and the Japan Aerospace Exploration Agency
Japan Aerospace Exploration Agency
The , or JAXA, is Japan's national aerospace agency. Through the merger of three previously independent organizations, JAXA was formed on October 1, 2003, as an Independent Administrative Institution administered by the Ministry of Education, Culture, Sports, Science and Technology and the...

 (JAXA) to the planet Mercury
Mercury (planet)
Mercury is the innermost and smallest planet in the Solar System, orbiting the Sun once every 87.969 Earth days. The orbit of Mercury has the highest eccentricity of all the Solar System planets, and it has the smallest axial tilt. It completes three rotations about its axis for every two orbits...

, due to launch in 2014. The mission is still in the planning stages so changes to the current description are likely over the next few years. Due to budgetary constraints and technological difficulties, the lander portion of the mission, the Mercury Surface Element (MSE) was cancelled.

Mission


The mission as currently envisioned involves three components: the Mercury Transfer Module (MTM) built by ESA, the Mercury Planetary Orbiter (MPO) built by ESA and the Mercury Magnetospheric Orbiter (MMO) built by JAXA (whose sunshield MOSIF (MMO Sunshield Interface) will be built by ESA). The prime contractor
General contractor
A general contractor is responsible for the day-to-day oversight of a construction site, management of vendors and trades, and communication of information to involved parties throughout the course of a building project.-Description:...

 for ESA is EADS Astrium
EADS Astrium
Astrium Satellites is one of the three business units of Astrium, a subsidiary of EADS. It is a European space manufacturer involved in the manufacture of spacecraft used for science, Earth observation and telecommunication, as well as the equipment and subsystems used therein and related ground...

. The three components are planned to be launched together on a Ariane 5
Ariane 5
Ariane 5 is, as a part of Ariane rocket family, an expendable launch system used to deliver payloads into geostationary transfer orbit or low Earth orbit . Ariane 5 rockets are manufactured under the authority of the European Space Agency and the Centre National d'Etudes Spatiales...

 launch vehicle in 2014. The spacecraft will have a six year interplanetary cruise to Mercury using solar-electric propulsion and gravity assists from the Moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...

, Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

, Venus
Venus
Venus is the second planet from the Sun, orbiting it every 224.7 Earth days. The planet is named after Venus, the Roman goddess of love and beauty. After the Moon, it is the brightest natural object in the night sky, reaching an apparent magnitude of −4.6, bright enough to cast shadows...

 and eventual gravity capture at Mercury
Mercury (planet)
Mercury is the innermost and smallest planet in the Solar System, orbiting the Sun once every 87.969 Earth days. The orbit of Mercury has the highest eccentricity of all the Solar System planets, and it has the smallest axial tilt. It completes three rotations about its axis for every two orbits...

.

Arriving in Mercury orbit in August 2020, the spacecraft will have a 1-year nominal scientific life. The MPO will be equipped with eleven scientific instruments provided by various European countries including visible imagers, a laser altimeter and an imaging X-ray spectrometer. Russia will provide a gamma ray and neutron spectrometer. It will attempt to map the entire surface in several different wavelength
Wavelength
In physics, the wavelength of a sinusoidal wave is the spatial period of the wave—the distance over which the wave's shape repeats.It is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings, and is a...

s, and to find water ice in polar craters which are permanently in shadow from the Sun's rays.

One of the goals of the mission is testing the general relativity
General relativity
General relativity or the general theory of relativity is the geometric theory of gravitation published by Albert Einstein in 1916. It is the current description of gravitation in modern physics...

 theory by measuring the parameters gamma and beta of the Parameterized post-Newtonian formalism
Parameterized post-Newtonian formalism
Post-Newtonian formalism is a calculational tool that expresses Einstein's equations of gravity in terms of the lowest-order deviations from Newton's theory. This allows approximations to Einstein's equations to be made in the case of weak fields...

 with high accuracy.
Date Event
19 July 2014 Launch
25 July 2015 Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

 flyby
17 January 2016 1st Venus
Venus
Venus is the second planet from the Sun, orbiting it every 224.7 Earth days. The planet is named after Venus, the Roman goddess of love and beauty. After the Moon, it is the brightest natural object in the night sky, reaching an apparent magnitude of −4.6, bright enough to cast shadows...

 flyby
29 August 2016 2nd Venus flyby
4 September 2017 1st Mercury
Mercury (planet)
Mercury is the innermost and smallest planet in the Solar System, orbiting the Sun once every 87.969 Earth days. The orbit of Mercury has the highest eccentricity of all the Solar System planets, and it has the smallest axial tilt. It completes three rotations about its axis for every two orbits...

 flyby
27 May 2018 2nd Mercury flyby
17 August 2019 3rd Mercury flyby
25 September 2019 4th Mercury flyby
21 May 2020-13 November 2020* Mercury orbit


*Depends on ion engine performance.

Mercury Transfer Module


The Mercury Transfer Module is at the base of the 'stack' and provides propulsion to escape Earth and to approach Mercury.
It carries no significant scientific instruments.

Mercury Planetary Orbiter (MPO)


The Mercury Planetary Orbiter will be a 357 kg spacecraft in the shape of a flat prism with three short sides slanted at 20 degrees covered with solar cells providing 420 W at perihelion. A radiator with an area of 1.5 square metres is mounted on one side to provide thermal control. The radiator is always pointed away from the Sun and is protected from planetary IR with a 3.4 square metre shield. High efficiency insulation is also used. A 1.5 m diameter high gain antenna is mounted on a short boom on the zenith side of the spacecraft. The MPO will be 3-axis stabilized and nadir pointing with a planned lifetime of over 1 year in Mercury orbit. Communications will be on the X/Ka band with an average bit rate of 50 kbit/s and a total data volume of 1550 Gb/year. A UHF dipole antenna mounted on the nadir side will be used for possible communications with the MSE. Navigation knowledge is provided by 3 star sensors.

The MPO will carry an imaging system consisting of a wide-angle and narrow angle camera, an infrared spectrometer, an ultraviolet spectrometer, gamm, X-ray, and neutron spectrometers, a laser altimeter, an ion and neutral spectrometer, a near-Earth object
Near-Earth object
A near-Earth object is a Solar System object whose orbit brings it into close proximity with the Earth. All NEOs have a perihelion distance less than 1.3 AU. They include a few thousand near-Earth asteroids , near-Earth comets, a number of solar-orbiting spacecraft, and meteoroids large enough to...

 telescope and detection system, and radio science experiments.

ESA has selected Astrium
EADS Astrium
Astrium Satellites is one of the three business units of Astrium, a subsidiary of EADS. It is a European space manufacturer involved in the manufacture of spacecraft used for science, Earth observation and telecommunication, as well as the equipment and subsystems used therein and related ground...

 as the prime contractor for the construction of the MPO.

Mercury Magnetospheric Orbiter (MMO)


The Mercury Magnetospheric Orbiter has the shape of a flat cylinder with a mass of roughly 250 kilograms (551.2 lb) including nitrogen gas for attitude control. The MMO is spin stabilized at 15 rpm with the spin axis perpendicular to the equator of Mercury. The top and bottom of the cylinder act as radiators with louvers for active temperature control. The side is covered with solar cells which provide 185 W and second surface mirrors and protected by thermal blankets. Communications with Earth are maintained through a despun 1-meter diameter high-gain offset antenna and two medium-gain antennas operating in the X-band. Telemetry will return 160 Gb of data per year at about 5 kbit/s over the lifetime of the craft, which is expected to be greater than one year. A microstrip UHF patch antenna will be used for communication with the MSE. The reaction and control system is based on cold gas thruster
Cold gas thruster
A cold gas thruster is a rocket engine/thruster that uses a gas as the reaction mass.A cold gas thruster usually simply consists of a pressurized tank containing gas, a valve to control its release and a nozzle, and plumbing connecting them...

s. Deployable booms and wire antennas are stowed until orbit is achieved. The MMO will carry a set of fluxgate magnetometers, charged particle detectors, a wave receiver, a positive ion emitter, and an imaging system.

Mercury Surface Element (MSE)


The Mercury Surface Element has been cancelled due to budgetary constraints.

At the time of cancellation, MSE was meant to be a small (44 kg) lander designed to operate for about one week on the surface of Mercury. Shaped as a 0.9 m diameter disc, it was designed to land at a latitude of 85 degrees near the terminator region. Following the release of the MMO, a burn of the 4 kN thruster would put the MSE into a 10 km orbit. Another braking maneuver controlled by gyros/accelerometers and an optical range/range-rate sensor would bring the MSE to zero velocity at an altitude of 120 metres at which point the propulsion unit would be ejected, the airbags inflated, and the module would fall to the surface with a maximum impact velocity of 30 m/s. If the landing occurs in sunlight a thermal protection cover would deploy. Since 40% of the terrain at the landing point would be in shadow, primary power would be supplied by a 1.7 kWh battery. Scientific data would be stored onboard and relayed via a cross-dipole UHF antenna to either the MPO or MMO at a data rate of 8.7 kbit/s, providing for a total of 75 Mb over 7 days, assuming 18 contact periods of 480 seconds each. The MSE would carry a 7 kg payload consisting of an imaging system (a descent camera and a surface camera), a heat flow and physical properties package, an alpha particle X-ray spectrometer
APXS
An Alpha Particle X-Ray Spectrometer is a device that analyses the chemical element composition of a sample from the scattered alpha particles, emitted protons , and fluorescent X-rays after the sample is irradiated with alpha particles and X-rays from radioactive sources...

, a magnetometer
Magnetometer
A magnetometer is a measuring instrument used to measure the strength or direction of a magnetic field either produced in the laboratory or existing in nature...

, a seismometer
Seismometer
Seismometers are instruments that measure motions of the ground, including those of seismic waves generated by earthquakes, volcanic eruptions, and other seismic sources...

, a soil penetrating device (mole), and a micro-rover
Rover (space exploration)
A rover is a space exploration vehicle designed to move across the surface of a planet or other astronomical body. Some rovers have been designed to transport members of a human spaceflight crew; others have been partially or fully autonomous robots...

.

Propulsion


The MTM (Mercury Transfer Module) will use two propulsion systems. A standard CPS (Chemical Propulsion System) which is bipropellant using MMH
Monomethylhydrazine
Monomethylhydrazine is a volatile hydrazine chemical with the chemical formula CH3 NH2. It is used as a rocket propellant in bipropellant rocket engines because it is hypergolic with various oxidizers such as nitrogen tetroxide and nitric acid...

/MON3. The CPS will be used for Earth escape and the Lunar fly-by. Post-Lunar escape the CPS will be pyrotechnically isolated and function in blowdown mode for the cruise. The spacecraft will be propelled in cruise by a form of ion drive dubbed solar electric propulsion, which has a very high specific impulse
Specific impulse
Specific impulse is a way to describe the efficiency of rocket and jet engines. It represents the derivative of the impulse with respect to amount of propellant used, i.e., the thrust divided by the amount of propellant used per unit time. If the "amount" of propellant is given in terms of mass ,...

 and very low thrust
Thrust
Thrust is a reaction force described quantitatively by Newton's second and third laws. When a system expels or accelerates mass in one direction the accelerated mass will cause a force of equal magnitude but opposite direction on that system....

. Unlike a chemical rocket which fires for a few seconds, it will keep propelling the craft for years, building up far more speed per mass of fuel in the long run. This will be the ESA's first mission outside the Earth–Moon system using such a form of propulsion. BepiColombo is also the largest solar electric mission so far planned.

This drive will be tested by the unusual need to actually push against the direction of travel, instead of with it; the ship will be falling toward the Sun, accelerated by its gravity, and will have to constantly fight to keep its velocity slow enough to eventually enter Mercury's orbit.

Namesake


BepiColombo is named for Giuseppe (Bepi) Colombo
Giuseppe Colombo
Giuseppe Colombo , better known by his nickname Bepi Colombo, was an Italian scientist, mathematician and engineer at the University of Padua, Italy Giuseppe Colombo (Padua, October 2, 1920 – Padua, February 20, 1984), better known by his nickname Bepi Colombo, was an Italian scientist,...

 (1920–1984), scientist
Scientist
A scientist in a broad sense is one engaging in a systematic activity to acquire knowledge. In a more restricted sense, a scientist is an individual who uses the scientific method. The person may be an expert in one or more areas of science. This article focuses on the more restricted use of the word...

, mathematician
Mathematician
A mathematician is a person whose primary area of study is the field of mathematics. Mathematicians are concerned with quantity, structure, space, and change....

 and engineer
Engineer
An engineer is a professional practitioner of engineering, concerned with applying scientific knowledge, mathematics and ingenuity to develop solutions for technical problems. Engineers design materials, structures, machines and systems while considering the limitations imposed by practicality,...

 at the University of Padua
University of Padua
The University of Padua is a premier Italian university located in the city of Padua, Italy. The University of Padua was founded in 1222 as a school of law and was one of the most prominent universities in early modern Europe. It is among the earliest universities of the world and the second...

, Italy
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...

, who developed the gravity-assist maneuver commonly used by planetary probes today. He helped NASA to devise the trajectory of Mariner 10
Mariner 10
Mariner 10 was an American robotic space probe launched by NASA on November 3, 1973, to fly by the planets Mercury and Venus. It was launched approximately two years after Mariner 9 and was the last spacecraft in the Mariner program...

, the only spacecraft to encounter Mercury during the twentieth century, exploiting this maneuver for the first time around Venus.

External links