BepiColombo#Mercury Transfer Module

BepiColombo is named after Giuseppe "Bepi" Colombo (1920–1984), a scientist, mathematician and engineer at the University of Padua, Italy, who first proposed the interplanetary gravity assist manoeuvre used by the 1974 Mariner 10 mission, a technique now used frequently by planetary probes.

Mio, the name of the Mercury Magnetospheric Orbiter, was selected from thousands of suggestions by the Japanese public. In Japanese, Mio means a waterway, and according to JAXA, it symbolizes the research and development milestones reached thus far, and wishes for safe travel ahead. JAXA said the spacecraft will travel through the solar wind just like a ship traveling through the ocean. In Chinese and Japanese, Mercury is known as the "water star" (水星) according to wǔxíng.

Following its Earth flyby in April 2020, BepiColombo was briefly mistaken for a near-Earth asteroid, receiving the provisional designation {{mp|2020 GL|2}}.{{cite web|url=https://minorplanetcenter.net/mpec/K20/K20G96.html|title=MPEC 2020-G96 : 2020 GL2|date=13 April 2020|publisher=Minor Planet Center|archive-url=https://web.archive.org/web/20200413144547/https://minorplanetcenter.net/mpec/K20/K20G96.html|archive-date=13 April 2020|url-status=dead}}{{cite web |url=https://minorplanetcenter.net/db_search/show_object?utf8=%E2%9C%93&object_id=2020+GL2|title=2020 GL2|date=13 April 2020|publisher=Minor Planet Center|archive-url=https://web.archive.org/web/20200413144626/https://minorplanetcenter.net/db_search/show_object?utf8=%E2%9C%93&object_id=2020+GL2|archive-date=13 April 2020|url-status=dead}}{{cite web|url=https://minorplanetcenter.net/mpec/K20/K20G97.html|title=MPEC 2020-G97 : DELETION OF 2020 GL2|date=13 April 2020|publisher=Minor Planet Center|access-date=14 April 2020}}{{Cite web|url=https://www.europlanet-society.org/bepicolombo-flies-by-earth/|title=BepiColombo flies by Earth|publisher=Europlanet Society|date=10 April 2020|access-date=24 June 2022|quote=The data collected for this image, even though it was submitted to the Minor Planet Center as artificial satellite 2018-080A (BepiColombo’s official designation), led to it being mistaken for a Near Earth asteroid. The “discovery”, announced by the Minor Planet Center as asteroid 2020 GL2, was retracted soon after. This was the third time a spacecraft had been mistakenly announced as a “new asteroid” during an Earth flyby, after Rosetta a.k.a. 2007 VN84 and Gaia a.k.a. 2015 HP116. Incidentally, all three of these are ESA missions.}}

The mission involves three components, which will separate into independent spacecraft upon arrival at Mercury.{{cite conference|url=http://lcpm9.jhuapl.edu/abstracts/Thursday/06_083_Hayakawa.pdf|title=BepiColombo Mercury Magnetospheric Orbiter (MMO)|conference=9th IAA Low-Cost Planetary Missions Conference. 21–23 June 2011, Laurel, Maryland|first1=Hajime|last1=Hayakawa|first2=Hironori|last2=Maejima|date=2011|access-date=15 August 2011|archive-date=23 February 2020|archive-url=https://web.archive.org/web/20200223200110/http://lcpm9.jhuapl.edu/abstracts/Thursday/06_083_Hayakawa.pdf|url-status=dead}}

• Mercury Transfer Module (MTM) for propulsion, built by ESA.
• Mercury Planetary Orbiter (MPO) built by ESA.
• Mercury Magnetospheric Orbiter (MMO) or Mio built by JAXA.

During the launch and cruise phases, these three components are joined together (with the Magnetospheric Orbiter Sunshield and Interface or MOSIF between Mio and MPO) to form the Mercury Cruise System (MCS).

The prime contractor for ESA is Airbus Defence and Space.{{cite web|url=http://sci.esa.int/bepicolombo/40691-bepicolombo-to-enter-implementation-phase/ |title=BepiColombo to Enter Implementation Phase|publisher=ESA|date=26 February 2007}} ESA is responsible for the overall mission, the design, development assembly and test of the propulsion and MPO modules, and the launch. The two orbiters, which are operated by mission controllers based in Darmstadt, Germany, were successfully launched together on 20 October 2018.{{cite news|last1=Amos|first1=Jonathan|title=Blast-off for BepiColombo on mission to Mercury |date=20 October 2018|url=https://www.bbc.co.uk/news/science-environment-45838991|publisher=BBC News|access-date=20 October 2018}} The launch took place on Ariane flight VA245 from Europe’s Spaceport in Kourou, French Guiana.{{cite news|url=https://www.esa.int/Science_Exploration/Space_Science/BepiColombo/Watch_BepiColombo_launch|title=Watch BepiColombo launch|publisher=European Space Agency|date=16 October 2018|accessdate=8 December 2021}} The spacecraft will have an eight-year interplanetary cruise to Mercury using solar-electric propulsion (ion thrusters) and gravity assists from Earth, Venus and eventual gravity capture at Mercury. ESA's Cebreros, Spain {{convert|35|m|adj=on}} ground station is planned to be the primary ground facility for communications during all mission phases.

Expected to arrive in Mercury orbit in November 2026, the Mio and MPO satellites will separate and observe Mercury in collaboration for one year, with a possible one-year extension. Although originally expected to enter orbit in December 2025, thruster issues discovered in September 2024 before its 4th flyby resulted in a delayed arrival of November 2026.{{cite web |title=esa-delays-bepicolombo-orbital-insertion-because-of-thruster-problem |url=https://spacenews.com/esa-delays-bepicolombo-orbital-insertion-because-of-thruster-problem/ |website=SpaceNews |publisher=SpaceNew |access-date=December 3, 2023}} The orbiters are equipped with scientific instruments provided by various European countries and Japan. The mission will characterize the solid and liquid iron core ({{frac|3|4}} of the planet's radius) and determine the size of each.[http://sci.esa.int/jump.cfm?oid=59928 Science with BepiColombo] ESA, Accessed: 23 October 2018 The mission will also complete gravitational and magnetic field mappings. Russia provided gamma ray and neutron spectrometers to verify the existence of water ice in polar craters that are permanently in shadow from the Sun's rays.

Mercury is too small and hot for its gravity to retain any significant atmosphere over long periods of time, but it has a "tenuous surface-bounded exosphere"{{cite journal |title=Mercury's Atmosphere: A Surface-Bounded Exosphere|journal=Space Science Reviews|last1=Domingue|first1=Deborah L.|last2=Koehn|first2=Patrick L.|last3=Killen|first3=Rosemary M.|last4=Sprague|first4=Ann L. |last5=Sarantos|first5=Menelaos|last6=Cheng|first6=Andrew F.|last7=Bradley|first7=Eric T.|last8=McClintock|first8=William E.|display-authors=2|volume=131|issue=1–4|pages=161–186|date=August 2007 |doi=10.1007/s11214-007-9260-9|bibcode=2007SSRv..131..161D|s2cid=121301247}} containing hydrogen, helium, oxygen, sodium, calcium, potassium and other trace elements. Its exosphere is not stable as atoms are continuously lost and replenished from a variety of sources. The mission will study the exosphere composition and dynamics, including generation and escape.

The main objectives of the mission are:{{cite web|url=http://sci.esa.int/bepicolombo/47346-fact-sheet/|title=BepiColombo: Fact Sheet|publisher=ESA|date=1 December 2016|access-date=13 December 2016}}

• Study the origin and evolution of a planet close to its parent star
• Study Mercury's form, interior, structure, geology, composition and craters
• Investigate Mercury's exosphere, composition and dynamics, including generation and escape
• Study Mercury's magnetised envelope (magnetosphere) – structure and dynamics
• Investigate the origin of Mercury's magnetic field
• Verify Einstein's theory of general relativity by measuring the parameters gamma and beta of the parameterized post-Newtonian formalism with high accuracy.{{cite web |url=http://sci.esa.int/bepicolombo/31277-general-relativity/|archive-url=https://archive.today/20140207202758/http://sci.esa.int/bepicolombo/31277-general-relativity/|url-status=dead|archive-date=7 February 2014|title=BepiColombo – Testing general relativity|publisher=ESA|date=4 July 2003|access-date=7 February 2014}}[https://www.sciencenews.org/article/einstein-general-relativity-mercury-orbit Einstein's general relativity reveals new quirk of Mercury's orbit] Emily Conover Science News 11 April 2018

File:MMO&MPO-Orbits.svg

The stacked spacecraft will take eight years to position itself to enter Mercury orbit. During this time it will use solar-electric propulsion and nine gravity assists, flying past the Earth and Moon in April 2020, Venus in 2020 and 2021, and six Mercury flybys between 2021 and 2025.

The stacked spacecraft left Earth with a hyperbolic excess velocity of {{cvt|3.475|km/s}}. Initially, the craft was placed in a heliocentric orbit similar to that of Earth. After both the spacecraft and Earth completed one and a half orbits, it returned to Earth to perform a gravity-assist maneuver and is deflected towards Venus. Two consecutive Venus flybys reduce the perihelion near to the Sun–Mercury distance with almost no need for thrust. A sequence of six Mercury flybys will lower the relative velocity to {{cvt|1.76|km/s}}. After the fourth Mercury flyby, the craft will be in an orbit similar to that of Mercury and will remain in the general vicinity of Mercury (see [http://sci.esa.int/bepicolombo/59288-bepicolombo-s-journey-to-mercury/video]). Four final thrust arcs reduce the relative velocity to the point where Mercury will "weakly" capture the spacecraft in November 2026 into polar orbit. Only a small maneuver is needed to bring the craft into an orbit around Mercury with an apocentre of {{convert|178,000|km}}. The orbiters then separate and will adjust their orbits using chemical thrusters.{{cite web|url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=BEPICLMBO |title=BepiColombo|work=National Space Science Data Center|publisher=NASA|date=26 August 2014|access-date=6 April 2015}} {{PD-notice}}{{cite web |url=http://sci.esa.int/bepicolombo/48871-getting-to-mercury/|title=Mission Operations – Getting to Mercury|publisher=ESA|access-date=7 February 2014}}

The BepiColombo mission proposal was selected by ESA in 2000. A request for proposals for the science payload was issued in 2004.[https://www.space.com/35671-bepicolombo-facts.html BepiColombo: Joint Mission to Mercury] Elizabeth Howell Space.com 21 October 2018 In 2007, Astrium was selected as the prime contractor, and Ariane 5 chosen as the launch vehicle. The initial target launch of July 2014 was postponed several times, mostly because of delays on the development of the solar electric propulsion system. The total cost of the mission was estimated in 2017 as US$2 billion.[https://spaceflightnow.com/2017/07/10/bepicolombo-mercury-mission-tested-for-journey-into-pizza-oven/ BepiColombo Mercury mission tested for journey into 'pizza oven'] Stephen Clarke Spaceflight Now 17 July 2017

File:Animation of BepiColombo trajectory.gif}}{{·}}{{legend2|Cyan|Venus}}{{·}}{{legend2|Lime|Mercury}}{{·}}{{legend2|Yellow|Sun}}
For more detailed animation, see this video]]

File:BepiColombo%E2%80%99s_second_Mercury_flyby.webm

File:Animation of BepiColombo trajectory around Mercury.gif

{{asof|January 2025}}, the mission schedule is:{{cite web |url=https://www.esa.int/Science_Exploration/Space_Science/BepiColombo/BepiColombo_factsheet|title=BepiColombo factsheet|website=ESA|access-date=2025-01-07}}

File:Timeline of BepiColombo.svg

File:BepiColombo_Earth_Flyby_10_april_2020.gif

File:BepiColombo NBO 2020-04-10.webm, 16 hours after the Earth flyby. The bright satellite passing by is INSAT-2D, a defunct geostationary satellite.]]

The Mercury Transfer Module (MTM) has a mass of {{cvt|2615|kg}}, including {{cvt|1400|kg}} of xenon propellant, and is located at the base of the stack. Its role is to carry the two science orbiters to Mercury and to support them during the cruise.

The MTM is equipped with a solar electric propulsion system as the main spacecraft propulsion. Its four QinetiQ-T6 ion thrusters operate singly or in pairs for a maximum combined thrust of 290 mN,{{cite conference|url=http://www.iepc2013.org/get?id=133|archive-url=https://web.archive.org/web/20161220114057/http://www.iepc2013.org/get?id=133|url-status=dead|archive-date=2016-12-20|title=BepiColombo Electric Propulsion Thruster and High Power Electronics Coupling Test Performances|conference=33rd International Electric Propulsion Conference 6–10 October 2013 Washington, D.C.|first1=Stephen D.|last1=Clark |first2=Mark S.|last2=Hutchins|first3=Ismat|last3=Rudwan|first4=Neil C.|last4=Wallace|first5=Javier|last5=Palencia|first6=Howard|last6=Gray|display-authors=2|date=2013|id=IEPC-2013-133}} making it the most powerful ion engine array ever operated in space. The MTM supplies electrical power for the two hibernating orbiters as well as for its solar electric propulsion system thanks to two {{convert|14|m||adj=mid|-long}} solar panels.{{cite web|url=http://sci.esa.int/bepicolombo/48872-spacecraft/|title=Mercury Planetary Orbiter – Spacecraft|publisher=ESA|date=16 August 2018|access-date=7 August 2019}} Depending on the probe's distance to the Sun, the generated power will range between 7 and 14 kW, each T6 requiring between 2.5 and 4.5 kW according to the desired thrust level.

The solar electric propulsion system has typically very high specific impulse and low thrust. This leads to a flight profile with months-long continuous low-thrust braking phases, interrupted by planetary gravity assists, to gradually reduce the velocity of the spacecraft. Moments before Mercury orbit insertion, the MTM will be jettisoned from the spacecraft stack. After separation from the MTM, the MPO will provide Mio all necessary power and data resources until Mio is delivered to its mission orbit; separation of Mio from MPO will be accomplished by spin-ejection.

Image:BepiColombo MPO ESTEC.jpg

File:Radio testing of BepiColombo orbiter ESA353568.jpg

The Mercury Planetary Orbiter (MPO) has a mass of {{cvt|1150|kg}} and uses a single-sided solar array capable of providing up to 1000 watts and featuring Optical Solar Reflectors to keep its temperature below {{cvt|200|C}}. The solar array requires continuous rotation keeping the Sun at a low incidence angle in order to generate adequate power while at the same time limiting the temperature.

The MPO will carry a payload of 11 instruments, comprising cameras, spectrometers (IR, UV, X-ray, γ-ray, neutron), a radiometer, a laser altimeter, a magnetometer, particle analysers, a Ka-band transponder, and an accelerometer. The payload components are mounted on the nadir side of the spacecraft to achieve low detector temperatures, apart from the MERTIS and PHEBUS spectrometers located directly at the main radiator to provide a better field of view.

A high-temperature-resistant {{cvt|1.0|m}} diameter high-gain antenna is mounted on a short boom on the zenith side of the spacecraft. Communications will be on the X-band and Ka-band with an average bit rate of 50 kbit/s and a total data volume of 1550 Gbit/year. ESA's Cebreros, Spain {{convert|35|m|adj=on}} ground station is planned to be the primary ground facility for communications during all mission phases.

File:MPO’s science instruments ESA17050215.jpeg

The science payload of the Mercury Planetary Orbiter consists of eleven instruments:{{cite web|url=http://sci.esa.int/bepicolombo/38831-instruments/ |title=Mercury Planetary Orbiter – Instruments|publisher=ESA|date=15 January 2008|access-date=6 February 2014}}

• BepiColombo Laser Altimeter (BELA), developed by DLR in cooperation with the University of Bern, the Max Planck Institute for Solar System Research (MPS) and the Instituto de Astrofísica de Andalucía.{{Cite web|url=https://www2.mps.mpg.de/en/projekte/bepicolombo/serena/|title = MPS: BepiColombo – SERENA}}
• Italian Spring Accelerometer (ISA), developed by Italy
• Mercury Magnetometer (MPO-MAG, MERMAG), developed by Germany and United Kingdom
• Mercury Radiometer and Thermal Infrared Spectrometer (MERTIS), developed by Germany
• Mercury Gamma-ray and Neutron Spectrometer (MGNS), developed by Russia
• Mercury Imaging X-ray Spectrometer (MIXS), developed and built by the University of Leicester, the Max Planck Institute for Solar System Research (MPS) and the Max Planck Institute for Extraterrestrial Physics (MPE).{{Cite web|url=https://www2.mps.mpg.de/en/projekte/bepicolombo/mixs/|title = MPS: MIXS on BepiColombo}}{{cite journal|last1=Fraser|first1=G.W.|last2=Carpenter |first2=J.D.|last3=Rothery|first3=D.A.|last4=Pearson|first4=J.F.|last5=Martindale|first5=A.|last6=Huovelin|first6=J.|last7=Treis|first7=J.|last8=Anand|first8=M.|last9=Anttila|first9=M.|last10=Ashcroft|first10=M.|last11=Benkoff|first11=J.|last12=Bland|first12=P.|last13=Bowyer|first13=A.|last14=Bradley|first14=A.|last15=Bridges|first15=J.|last16=Brown|first16=C.|last17=Bulloch|first17=C.|last18=Bunce|first18=E.J.|last19=Christensen|first19=U.|last20=Evans|first20=M.|last21=Fairbend|first21=R.|last22=Feasey|first22=M.|last23=Giannini|first23=F.|last24=Hermann|first24=S.|last25=Hesse|first25=M.|last26=Hilchenbach|first26=M.|last27=Jorden|first27=T.|last28=Joy|first28=K.|author-link28=Katherine Joy|last29=Kaipiainen|first29=M.|last30=Kitchingman|first30=I.|last31=Lechner|first31=P.|last32=Lutz|first32=G.|last33=Malkki|first33=A. |last34=Muinonen|first34=K.|last35=Näränen|first35=J.|last36=Portin|first36=P.|last37=Prydderch|first37=M.|last38=Juan|first38=J. San|last39=Sclater|first39=E.|last40=Schyns|first40=E.|last41=Stevenson |first41=T.J.|last42=Strüder|first42=L.|last43=Syrjasuo|first43=M.|last44=Talboys|first44=D.|last45=Thomas|first45=P.|last46=Whitford|first46=C.|last47=Whitehead|first47=S.|title=The mercury imaging X-ray spectrometer (MIXS) on bepicolombo|journal=Planetary and Space Science|volume=58|issue=1–2|year=2010|pages=79–95|issn=0032-0633|doi=10.1016/j.pss.2009.05.004|bibcode=2010P&SS...58...79F |url=http://oro.open.ac.uk/16347/}}
• Mercury Orbiter Radio-science Experiment (MORE), developed by Italy and the United States
• Probing of Hermean Exosphere by Ultraviolet Spectroscopy (PHEBUS), developed by France and Russia
• Search for Exosphere Refilling and Emitted Neutral Abundances (SERENA),{{cite web|url=https://www.cosmos.esa.int/web/bepicolombo/serena|title=SERENA|publisher=ESA|access-date=7 August 2019}} made up of 2 neutral and 2 ionised particle analysers:
• ELENA (Emitted Low-Energy Neutral Atoms) developed by Italy;
• STROFIO (STart from a ROtating Field mass spectrOmeter) developed by United States;{{cite web |url=https://discovery.nasa.gov/strofio.cfml|title=Strofio|series=Discovery Program|publisher=NASA|access-date=7 January 2017|url-status=dead|archive-url=https://web.archive.org/web/20170108093835/https://discovery.nasa.gov/strofio.cfml|archive-date=8 January 2017}} {{PD-notice}}
• MIPA (Miniature Ion Precipitation Analyser) developed by Sweden;
• PICAM (Planetary Ion CAMera) developed by the Space Research Institute (Institut für Weltraumforschung, IWF), Russian Space Research Institute (IKI), Institut de recherche en sciences de l'environnement (CETP/IPSL), European Space Research and Technology Centre (ESTEC), Research Institute for Particle and Nuclear Physics (KFKI-RMKI) and the Max Planck Institute for Solar System Research (MPS).
• Spectrometers and Imagers for MPO BepiColombo Integrated Observatory System (SIMBIO-SYS), high resolution stereo cameras and a visual and near infrared spectrometer, developed by Italy, France and Switzerland
• Solar Intensity X-ray and Particle Spectrometer (SIXS), developed by Finland and United Kingdom.

Image:BepiColombo MMO ESTEC.jpg

Mio, or the Mercury Magnetospheric Orbiter (MMO), developed and built mostly by Japan, has the shape of a short octagonal prism, {{cvt|180|cm}} long from face to face and {{cvt|90|cm}} high.{{cite journal|title=Current status of the BepiColombo/MMO spacecraft design|journal=Advances in Space Research|first1=Hiroshi|last1=Yamakawa|first2=Hiroyuki|last2=Ogawa |first3=Yasumasa|last3=Kasaba|first4=Hajime|last4=Hayakawa|first5=Toshifumi|last5=Mukai|first6=Masaki|last6=Adachi|display-authors=2|volume=33|issue=12|pages=2133–2141|date=January 2004|doi=10.1016/S0273-1177(03)00437-X|bibcode=2004AdSpR..33.2133Y}} It has a mass of {{cvt|285|kg}}, including a {{cvt|45|kg}} scientific payload consisting of 5 instrument groups, 4 for plasma and dust measuring run by investigators from Japan, and one magnetometer from Austria.{{cite web|url=http://global.jaxa.jp/activity/pr/brochure/files/sat27.pdf |title=Mercury Exploration Project "BepiColombo"|publisher=JAXA|date=2014|access-date=6 April 2015}}{{cite web|title=A pair of planetary Explorers at Mercury|url=http://sci.esa.int/bepicolombo/59934-spacecraft-duo/|website=esa.int|access-date=21 October 2018}}

Mio will be spin stabilized at 15 rpm with the spin axis perpendicular to the equator of Mercury. It will enter a polar orbit at an altitude of {{cvt|590|xx|11640|km}}, outside of MPO's orbit. The top and bottom of the octagon act as radiators with louvers for active temperature control. The sides are covered with solar cells which provide 90 watts. Communications with Earth will be through a {{cvt|0.8|m}} diameter X-band phased array high-gain antenna and two medium-gain antennas operating in the X-band. Telemetry will return 160 Gb/year, about 5 kbit/s over the lifetime of the spacecraft, which is expected to be greater than one year. The reaction and control system is based on cold gas thrusters. After its release in Mercury orbit, Mio will be operated by Sagamihara Space Operation Center using Usuda Deep Space Center{{'s}} {{cvt|64|m}} antenna located in Nagano, Japan.{{cite web|url=http://www.stp.isas.jaxa.jp/mercury/p_mmo.html|title=MMO (Mercury Magnetospheric Orbiter): Objectives|publisher=JAXA|date=2011|access-date=7 February 2014}}

File:The search for volcanoes (annotated) ESA24328694.png

Mio carries five groups of science instruments with a total mass of {{cvt|45|kg}}:

• Mercury Plasma Particle Experiment (MPPE), studies the plasma and neutral particles from the planet, its magnetosphere, and the solar wind. It will employ these instruments:
• Mercury Electron Analyzers (MEA1 and MEA2)
• Mercury Ion Analyzer (MIA)
• Mass Spectrum Analyzer (MSA), developed by Laboratory of Plasma Physics (LPP), Max Planck Institute for Solar System Research (MPS), IDA of Technical University of Braunschweig and Institute of Space and Astronautical Science (ISAS) {{Cite web|url=https://www.mps.mpg.de/planetenforschung/bepi-colombo-mppe|title = MPPE}}
• High-Energy Particle instrument for electrons (HEP-ele)
• High-Energy Particle instrument for Ions (HEP-ion)
• Energetic Neutrals Analyzer (ENA)
• Mercury Magnetometer (MMO-MGF), studies Mercury's magnetic field, magnetosphere, and interplanetary solar wind
• Plasma Wave Investigation (PWI), studies the electric field, electromagnetic waves, and radio waves from the magnetosphere and solar wind
• Mercury Sodium Atmosphere Spectral Imager (MSASI), studies the thin sodium atmosphere of Mercury
• Mercury Dust Monitor (MDM), studies dust from the planet and interplanetary space

The Mio orbiter requires additional thermal control on the cruise to Mercury, in addition to umbilicals to the MPO. The European Space Agency thus provided the Magnetospheric Orbiter Sunshield and Interface (MOSIF), a white shroud that is shaped like a conical frustrum to provide clearance, as Mio is spun up during its separation in 2026, before being ejected from the MPO.{{cite web | title=Magnetospheric Orbiter Sunshield and Interface Shaker Test | website=ESA Science & Technology | date=29 September 2011 | url= https://sci.esa.int/web/bepicolombo/-/49501-magnetospheric-orbiter-sunshield-and-interface-structure-mosif-shaker-test | access-date=4 January 2025}}{{cite web | title=BepiColombo Flyby | website=BepiColombo Flyby | date=October 20, 2018 | url=https://www.cosmos.esa.int/web/bepicolombo-flyby | access-date=January 4, 2025}}{{cite web | title=BepiColombo arrival at Mercury timeline | website=ESA | url=https://www.esa.int/ESA_Multimedia/Images/2018/10/BepiColombo_arrival_at_Mercury_timeline | access-date=4 January 2025}}

The Mercury Surface Element (MSE) was cancelled in 2003 due to budgetary constraints.{{cite press release |url=http://www.esa.int/For_Media/Press_Releases/Critical_decisions_on_Cosmic_Vision|title=Critical Decisions on Cosmic Vision|publisher=ESA|date=7 November 2003|access-date=14 December 2016|id=No. 75-2003}} At the time of cancellation, MSE was meant to be a small, {{cvt|44|kg}}, lander designed to operate for about one week on the surface of Mercury. Shaped as a {{cvt|0.9|m}} diameter disc, it was designed to land at a latitude of 85° near the terminator region. Braking manoeuvres would bring the lander to zero velocity at an altitude of {{cvt|120|m}} at which point the propulsion unit would be ejected, airbags inflated, and the module would fall to the surface with a maximum impact velocity of {{cvt|30|m/s}}. Scientific data would be stored onboard and relayed via a cross-dipole UHF antenna to either the MPO or Mio. The MSE would have carried a {{cvt|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, a magnetometer, a seismometer, a soil penetrating device (mole), and a micro-rover.{{cite web |url=http://www.esa.int/spaceinimages/Images/2001/11/BepiColombo_s_lander|title=BepiColombo's lander|publisher=ESA|date=20 February 2002|access-date=7 February 2014}}

• Exploration of Mercury
• MESSENGER – the first spacecraft to orbit Mercury

{{Reflist}}

{{Commons}}

• [https://www.esa.int/Science_Exploration/Space_Science/BepiColombo BepiColombo website] by the European Space Agency
• [http://www.esa.int/Our_Activities/Operations/BepiColombo_operations BepiColombo Operations website] by the European Space Agency
• [https://global.jaxa.jp/projects/sas/bepi BepiColombo website] by JAXA
• [http://www.isas.jaxa.jp/en/missions/spacecraft/developing/mmo.html BepiColombo website] by JAXA's Institute of Space and Astronautical Science
• [https://solarsystem.nasa.gov/missions/bepicolombo/in-depth/ BepiColombo website] by NASA's Solar System Exploration
• [https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=BEPICLMBO BepiColombo website] by the National Space Science Data Center
• [https://link.springer.com/journal/11214/topicalCollection/AC_76aacd1766d3980239c6d84531056577/page/1 The BepiColombo mission to Mercury], edited by Johannes Benkhoff, Go Murakami and Ayako Matsuoka. Space Science Reviews. 216–217 (2020–2021)
• [https://www.eoportal.org/satellite-missions/bepicolombo BepiColombo article on eoPortal by ESA]

{{Portal bar|Astronomy|Stars|Spaceflight|Solar System}}

{{Mercury (planet)}}

{{Mercury spacecraft}}

{{Venus spacecraft}}

{{ESA projects}}

{{Japanese space program}}

{{Planetary Missions Program Office|Discovery=y}}

{{Solar System probes}}

{{Orbital launches in 2018}}

{{2018 in space}}

Category:Missions to Mercury

Category:European Space Agency space probes

Category:Japanese space probes

Category:Orbiters (space probe)

Category:Space probes launched in 2018

Category:Spacecraft launched by Ariane rockets

Category:2018 in French Guiana