Mission type | Planetary science |
---|---|
Operator | |
COSPAR ID | 2018-080A |
SATCAT no. | 43653 |
Mission duration | Cruise: 7 years (planned) 8 years (actual) Science phase: 1 year (planned) 6 years, 1 month and 14 days (in progress) |
Spacecraft properties | |
Manufacturer | |
Launch mass | 4,100 kg (9,000 lb) [1] |
BOL mass | MPO: 1,230 kg (2,710 lb) Mio: 255 kg (562 lb) [1] |
Dry mass | 2,700 kg (6,000 lb) [1] |
Dimensions | MPO: 2.4 m × 2.2 m × 1.7 m (7 ft 10 in × 7 ft 3 in × 5 ft 7 in) Mio: 1.8 m × 1.1 m (5 ft 11 in × 3 ft 7 in) [1] |
Power | MPO: 150 watts Mio: 90 watts |
Start of mission | |
Launch date | 20 October 2018, 01:45 UTC |
Rocket | Ariane 5 ECA (VA245) [2] |
Launch site | Centre Spatial Guyanais, ELA-3 [3] |
Contractor | Arianespace |
Flyby of Earth (gravity assist) | |
Closest approach | 10 April 2020, 04:25 UTC |
Distance | 12,677 km (7,877 mi) |
Flyby of Venus (gravity assist) | |
Closest approach | 15 October 2020,03:58 UTC |
Distance | 10,720 km (6,660 mi) |
Flyby of Venus (gravity assist) | |
Closest approach | 10 August 2021,13:51 UTC |
Distance | 552 km (343 mi) |
Flyby of Mercury (gravity assist) | |
Closest approach | 1 October 2021,23:34:41 UTC |
Distance | 199 km (124 mi) |
Flyby of Mercury (gravity assist) | |
Closest approach | 23 June 2022,09:44 UTC |
Distance | 200 km (124.3 mi) |
Flyby of Mercury (gravity assist) | |
Closest approach | 19 June 2023,19:34 UTC |
Distance | 236 km (147 mi) |
Mercury orbiter | |
Spacecraft component | Mercury Planetary Orbiter (MPO) |
Orbital insertion | November 2026 (planned) |
Orbital parameters | |
Perihermion altitude | 480 km (300 mi) |
Apohermion altitude | 1,500 km (930 mi) |
Inclination | 90,0° |
Mercury orbiter | |
Spacecraft component | Mercury Magnetospheric Orbiter (MMO) |
Orbital insertion | November 2026 (planned) |
Orbital parameters | |
Perihermion altitude | 590 km (370 mi) |
Apohermion altitude | 11,640 km (7,230 mi) |
Inclination | 90.0° |
BepiColombo insignia |
BepiColombo is a joint mission of the European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA) to the planet Mercury. [4] The mission comprises two satellites launched together:the Mercury Planetary Orbiter (MPO) and Mio (Mercury Magnetospheric Orbiter,MMO). [5] The mission will perform a comprehensive study of Mercury,including characterization of its magnetic field,magnetosphere,and both interior and surface structure. It was launched on an Ariane 5 [2] rocket on 20 October 2018 at 01:45 UTC,with an arrival at Mercury planned for November 2026,after a flyby of Earth,two flybys of Venus,and six flybys of Mercury. [1] [6] The mission was approved in November 2009,after years in proposal and planning as part of the European Space Agency's Horizon 2000+ programme; [7] it is the last mission of the programme to be launched. [8]
On 15 May 2024,ESA reported that a "glitch" prevented the spacecraft's thrusters from operating at full power during a scheduled manoeuvre on 26 April. [9] On 2 September,ESA reported that to compensate for the reduced available thrust,a revised trajectory had been developed that would add 11 months to the cruise,delaying the expected arrival date from 5 December 2025 to November 2026. [10]
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. [5] 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 2020 GL2. [11] [12] [13] [14]
The mission involves three components,which will separate into independent spacecraft upon arrival at Mercury. [15]
During the launch and cruise phases,these three components are joined together to form the Mercury Cruise System (MCS).
The prime contractor for ESA is Airbus Defence and Space. [16] 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. [17] The launch took place on Ariane flight VA245 from Europe’s Spaceport in Kourou,French Guiana. [18] The spacecraft will have a eight-year interplanetary cruise to Mercury using solar-electric propulsion (ion thrusters) and gravity assists from Earth,Venus and eventual gravity capture at Mercury. [1] ESA's Cebreros,Spain 35-metre (115 ft) 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. [1] 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. [19] The orbiters are equipped with scientific instruments provided by various European countries and Japan. The mission will characterize the solid and liquid iron core (3⁄4 of the planet's radius) and determine the size of each. [20] 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" [21] 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: [3] [22]
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. [1]
The stacked spacecraft left Earth with a hyperbolic excess velocity of 3.475 km/s (2.159 mi/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 1.76 km/s (1.09 mi/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 ). 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 178,000 kilometres (111,000 mi). The orbiters then separate and will adjust their orbits using chemical thrusters. [25] [26]
The BepiColombo mission proposal was selected by ESA in 2000. A request for proposals for the science payload was issued in 2004. [27] In 2007, Astrium was selected as the prime contractor, and Ariane 5 chosen as the launch vehicle. [27] The initial target launch of July 2014 was postponed several times, mostly because of delays on the development of the solar electric propulsion system. [27] The total cost of the mission was estimated in 2017 as US$2 billion. [28]
As of 2021 [update] , the mission schedule is: [1]
Date | Event | Comment |
---|---|---|
20 October 2018, 01:45 UTC | Launch | |
10 April 2020, 04:25 UTC | Earth flyby | 1.5 years after launch |
15 October 2020, 03:58 UTC | First Venus flyby | According to Johannes Benkhoff of ESA, the probe may possibly be capable of detecting phosphine – the chemical allegedly discovered in the Venusian atmosphere in September 2020 – during this and the following flyby. He stated that "we do not know if our instrument is sensitive enough". [29] On 15 October 2020, the ESA reported the flyby was a success. [30] |
10 August 2021, 13:51 UTC | Second Venus flyby | 1.35 Venus years after first Venus flyby. Flyby was a success, and saw BepiColombo come within 552 kilometres (343 mi) of Venus' surface. [31] [32] |
1 October 2021, 23:34:41 UTC | First Mercury flyby | Passed 199 kilometres (124 mi) from Mercury's surface. [33] Occurred on what would have been the 101st birthday of Giuseppe Colombo. |
23 June 2022, 09:44 UTC | Second Mercury flyby | 2 orbits (3.00 Mercury years) after 1st Mercury flyby. Closest approach of about 200 kilometres (120 mi) altitude. [34] |
19 June 2023, 19:34 UTC | Third Mercury flyby | >3 orbits (4.12 Mercury years) after 2nd Mercury flyby. Closest approach of about 236 kilometres (147 mi) altitude. [35] [36] |
4 September 2024, 21:48 UTC | Fourth Mercury flyby | ~4 orbits (5.04 Mercury years) after 3rd Mercury flyby. Closest approach of about 165 kilometres (103mi) altitude. [37] |
1 December 2024 | Fifth Mercury flyby | 1 orbit (1.00 Mercury year) after 4th Mercury flyby |
8 January 2025 | Sixth Mercury flyby | ~0.43 orbits (0.43 Mercury years) after 5th Mercury flyby |
November 2026 | Mercury orbit insertion | Spacecraft separation; ~7 Mercury years after 6th Mercury flyby |
2027 | MPO in final science orbit | 1.13 Mercury years after orbit insertion? |
April 2028 | End of nominal mission | 5.82 Mercury years after orbit insertion |
April 2029 | End of extended mission | 9.98 Mercury years after orbit insertion |
QinetiQ T6 | Performance [38] [39] |
---|---|
Type | Kaufman Ion Engine |
Units on board | 4 [40] [41] |
Diameter | 22 cm (8.7 in) |
Max. thrust | 145 mN each |
Specific impulse (Isp) | 4300 seconds |
Propellant | Xenon |
Total power | 4628 W |
The Mercury Transfer Module (MTM) has a mass of 2,615 kg (5,765 lb), including 1,400 kg (3,100 lb) 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, [42] 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 14-metre-long (46 ft) solar panels. [43] 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. [43] 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.
The Mercury Planetary Orbiter (MPO) has a mass of 1,150 kg (2,540 lb) and uses a single-sided solar array capable of providing up to 1000 watts and featuring Optical Solar Reflectors to keep its temperature below 200 °C (392 °F). 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. [43]
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. [43]
A high-temperature-resistant 1.0 m (3 ft 3 in) 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 35-metre (115 ft) ground station is planned to be the primary ground facility for communications during all mission phases. [43]
The science payload of the Mercury Planetary Orbiter consists of eleven instruments: [44] [45]
Mio, or the Mercury Magnetospheric Orbiter (MMO), developed and built mostly by Japan, has the shape of a short octagonal prism, 180 cm (71 in) long from face to face and 90 cm (35 in) high. [3] [51] It has a mass of 285 kg (628 lb), including a 45 kg (99 lb) scientific payload consisting of 5 instrument groups, 4 for plasma and dust measuring run by investigators from Japan, and one magnetometer from Austria. [3] [52] [53]
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 590 × 11,640 km (370 × 7,230 mi), outside of MPO's orbit. [52] 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 0.8 m (2 ft 7 in) 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 's64 m (210 ft) antenna located in Nagano, Japan. [44]
Mio carries five groups of science instruments with a total mass of 45 kg (99 lb): [3] [44]
The Mercury Surface Element (MSE) was cancelled in 2003 due to budgetary constraints. [8] At the time of cancellation, MSE was meant to be a small, 44 kg (97 lb), lander designed to operate for about one week on the surface of Mercury. [25] Shaped as a 0.9 m (2 ft 11 in) 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 120 m (390 ft) 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 30 m/s (98 ft/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 7 kg (15 lb) 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. [55]
A gravity assist, gravity assist maneuver, swing-by, or generally a gravitational slingshot in orbital mechanics, is a type of spaceflight flyby which makes use of the relative movement and gravity of a planet or other astronomical object to alter the path and speed of a spacecraft, typically to save propellant and reduce expense.
SMART-1 was an European Space Agency satellite that orbited the Moon. It was launched on 27 September 2003 at 23:14 UTC from the Guiana Space Centre in Kourou, French Guiana. "SMART-1" stands for Small Missions for Advanced Research in Technology-1. On 3 September 2006, SMART-1 was deliberately crashed into the Moon's surface, ending its mission.
Nozomi was a Japanese Mars orbiter that failed to reach Mars due to electrical failure. It was constructed by the Institute of Space and Astronautical Science, University of Tokyo and launched on July 4, 1998, at 03:12 JST with an on-orbit dry mass of 258 kg and 282 kg of propellant. The Nozomi mission was terminated on December 31, 2003.
MESSENGER was a NASA robotic space probe that orbited the planet Mercury between 2011 and 2015, studying Mercury's chemical composition, geology, and magnetic field. The name is a backronym for Mercury Surface, Space Environment, Geochemistry, and Ranging, and a reference to the messenger god Mercury from Roman mythology.
Solar electric propulsion (SEP) refers to the combination of solar cells and electric thrusters to propel a spacecraft through outer space. This technology has been exploited in a variety of spacecraft designs by the European Space Agency (ESA), the JAXA, Indian Space Research Organisation (ISRO) and NASA. SEP has a significantly higher specific impulse than chemical rocket propulsion, thus requiring less propellant mass to be launched with a spacecraft. The technology has been evaluated for missions to Mars.
The gridded ion thruster is a common design for ion thrusters, a highly efficient low-thrust spacecraft propulsion method running on electrical power by using high-voltage grid electrodes to accelerate ions with electrostatic forces.
Giuseppe "Bepi" Colombo was an Italian scientist, mathematician and engineer at the University of Padua, Italy.
The Solar Orbiter (SolO) is a Sun-observing probe developed by the European Space Agency (ESA) with a National Aeronautics and Space Administration (NASA) contribution. Solar Orbiter, designed to obtain detailed measurements of the inner heliosphere and the nascent solar wind, will also perform close observations of the polar regions of the Sun which is difficult to do from Earth. These observations are important in investigating how the Sun creates and controls its heliosphere.
Observations of the planet Venus include those in antiquity, telescopic observations, and from visiting spacecraft. Spacecraft have performed various flybys, orbits, and landings on Venus, including balloon probes that floated in the atmosphere of Venus. Study of the planet is aided by its relatively close proximity to the Earth, compared to other planets, but the surface of Venus is obscured by an atmosphere opaque to visible light.
The following outline is provided as an overview of and topical guide to space exploration.
The exploration of Mercury has a minor role in the space interests of the world. It is the least explored inner planet. As of 2015, the Mariner 10 and MESSENGER missions have been the only missions that have made close observations of Mercury. MESSENGER made three flybys before entering orbit around Mercury. A third mission to Mercury, BepiColombo, a joint mission between the Japan Aerospace Exploration Agency (JAXA) and the European Space Agency, is to include two probes. MESSENGER and BepiColombo are intended to gather complementary data to help scientists understand many of the mysteries discovered by Mariner 10's flybys.
Mercury, being the closest to the Sun, with a weak magnetic field and the smallest mass of the recognized terrestrial planets, has a very tenuous and highly variable atmosphere containing hydrogen, helium, oxygen, sodium, calcium, potassium and water vapor, with a combined pressure level of about 10−14 bar. The exospheric species originate either from the Solar wind or from the planetary crust. Solar light pushes the atmospheric gases away from the Sun, creating a comet-like tail behind the planet.
Energetic Neutral Atom (ENA) imaging is a technology used to create global images of otherwise invisible phenomena in the magnetospheres of planets and throughout the heliosphere.
Mercury's magnetic field is approximately a magnetic dipole, apparently global, on the planet of Mercury. Data from Mariner 10 led to its discovery in 1974; the spacecraft measured the field's strength as 1.1% that of Earth's magnetic field. The origin of the magnetic field can be explained by dynamo theory. The magnetic field is strong enough near the bow shock to slow the solar wind, which induces a magnetosphere.
The Jupiter Icy Moons Explorer is an interplanetary spacecraft on its way to orbit and study three icy moons of Jupiter: Ganymede, Callisto, and Europa. These planetary-mass moons are planned to be studied because they are thought to have significant bodies of liquid water beneath their frozen surfaces, which would make them potentially habitable for extraterrestrial life.
Hisaki, also known as the Spectroscopic Planet Observatory for Recognition of Interaction of Atmosphere (SPRINT-A) was a Japanese ultraviolet astronomy satellite operated by the Japan Aerospace Exploration Agency (JAXA). The first mission of the Small Scientific Satellite program, it was launched in September 2013 on the maiden flight of the Epsilon rocket. It was used for extreme ultraviolet observations of the Solar System planets.
OKEANOS was a proposed mission concept to Trojan asteroids, which share Jupiter's orbit, using a hybrid solar sail for propulsion; the sail was planned to be covered with thin solar panels to power an ion engine. In situ analysis of the collected samples would have been performed by either direct contact or using a lander carrying a high-resolution mass spectrometer. A sample-return to Earth was an option under study.
Ariane Flight VA245 is the Ariane 5 space launch of BepiColombo that took place on 20 October 2018 at 01:45:28 UTC from the Guiana Space Centre. It was the 101st launch of Ariane 5, and the 301st Arianespace mission.
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 flyby itself was very successful", confirms Elsa. "The only difference to normal cruise phase operations is that near to Venus we have to temporarily close the shutter of any of the star trackers that are expected to be blinded by the planet, similar to closing your eyes to avoid looking at the Sun
Our #BepiColombo @esaoperations team confirm all went well with our #MercuryFlyby last night! Now we wait and see what images & data our instrument teams collected