The Solar Orbiter (SolO) is a
Sun
The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...
-observing
satellite
A satellite or artificial satellite is an object intentionally placed into orbit in outer space. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioisotope ...
developed by the
European Space Agency
, owners =
, headquarters = Paris, Île-de-France, France
, coordinates =
, spaceport = Guiana Space Centre
, seal = File:ESA emblem seal.png
, seal_size = 130px
, image = Views in the Main Control Room (1205 ...
(ESA). SolO, designed to obtain detailed measurements of the inner
heliosphere
The heliosphere is the magnetosphere, astrosphere and outermost atmospheric layer of the Sun. It takes the shape of a vast, bubble-like region of space. In plasma physics terms, it is the cavity formed by the Sun in the surrounding interstell ...
and the nascent
solar wind
The solar wind is a stream of charged particles released from the upper atmosphere of the Sun, called the corona. This plasma mostly consists of electrons, protons and alpha particles with kinetic energy between . The composition of the sola ...
, 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.
SolO makes observations of the Sun from an eccentric orbit moving as close as ≈60
solar radii (RS), or 0.284
astronomical unit
The astronomical unit (symbol: au, or or AU) is a unit of length, roughly the distance from Earth to the Sun and approximately equal to or 8.3 light-minutes. The actual distance from Earth to the Sun varies by about 3% as Earth orbits t ...
s (au), placing it inside
Mercury's
perihelion
An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion.
General description
There are two apsides in any ellip ...
of 0.3075 au. During the mission the orbital inclination will be raised to about 24°. The total mission cost is US$1.5 billion, counting both ESA and NASA contributions.
SolO was launched on 10 February 2020. The mission is planned to last seven years.
Spacecraft
The Solar Orbiter spacecraft is a Sun-pointed, three-axis stabilised platform with a dedicated heat shield to provide protection from the high levels of solar flux near perihelion. The spacecraft provides a stable platform to accommodate the combination of remote-sensing and in situ instrumentation in an electromagnetically clean environment. The 21 sensors were configured on the spacecraft to allow each to conduct its in situ or remote-sensing experiments with both access to and protection from the solar environment. Solar Orbiter has inherited technology from previous missions, such as the solar arrays from the
BepiColombo
BepiColombo is a joint mission of the European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA) to the planet Mercury. The mission comprises two satellites launched together: the Mercury Planetary Orbiter (MPO) and ''Mio'' ...
Mercury Planetary Orbiter (MPO). The
solar arrays
A photovoltaic system, also PV system or solar power system, is an electric power system designed to supply usable solar power by means of photovoltaics. It consists of an arrangement of several components, including solar panels to absorb and c ...
can be rotated about their longitudinal axis to avoid overheating when close to the Sun. A battery pack provides supplementary power at other points in the mission such as eclipse periods encountered during planetary flybys.
The Telemetry, Tracking and Command Subsystem provides the communication link capability with the Earth in X-band. The subsystem supports telemetry, telecommand and ranging. Low-Gain Antennas are used for Launch and Early Orbit Phase (LEOP) and now function as a back-up during the mission phase when steerable Medium- and High-Gain Antennas are in use. The High-Temperature High-Gain Antenna needs to point to a wide range of positions to achieve a link with the ground station and to be able to downlink sufficient volumes of data. Its design was adapted from the BepiColombo mission. The antenna can be folded in to gain protection from Solar Orbiter's heat shield if necessary. Most data will therefore initially be stored in on-board memory and sent back to Earth at the earliest possible opportunity.
The ground station at
Malargüe
Malargüe () is a city in the southwest part of province of Mendoza, Argentina, about 370 km south of the provincial capital Mendoza. It is the head town of the Malargüe Department, and it has about 27,000 inhabitants as per the .
Overvie ...
(Argentina), with a 35-m antenna, is used for 4 to 8 hours/day (effective). ESA's Malargüe ground station will be used for all operations throughout the mission with the ground stations in
New Norcia
New is an adjective referring to something recently made, discovered, or created.
New or NEW may refer to:
Music
* New, singer of K-pop group The Boyz
Albums and EPs
* ''New'' (album), by Paul McCartney, 2013
* ''New'' (EP), by Regurgitator, ...
, Australia, and
Cebreros
Cebreros () is a municipality of Spain, located in the province of Ávila, part of the autonomous community of Castile and León. As of 2018 it had a population of 3,056. The municipality covers an area of 137.47 km2. It lies at 755 metres ...
, Spain, acting as backup when necessary.
[
]
Mission operations
During nominal science operations, science data is downlinked for eight hours during each communication period with the ground station. Additional eight-hour downlink passes are scheduled as needed to reach the required total science data return of the mission. The Solar Orbiter ground segment makes maximum reuse of ESA's infrastructure for Deep Space missions:
* The ground stations, which belong to ESA's space tracking station network (ESTRACK
The European Space Tracking (ESTRACK) network consists of a number of ground-based space-tracking stations belonging to the European Space Agency (ESA), and operated by the European Space Operations Centre (ESOC) in Darmstadt, Germany. The station ...
)
* The Mission Operations Centre (MOC), located at ESOC
The European Space Operations Centre (ESOC) serves as the main mission control centre for the European Space Agency (ESA) and is located in Darmstadt, Germany. ESOC's primary function is the operation of unmanned spacecraft on behalf of ESA and ...
, Darmstadt
Darmstadt () is a city in the States of Germany, state of Hesse in Germany, located in the southern part of the Frankfurt Rhine Main Area, Rhine-Main-Area (Frankfurt Metropolitan Region). Darmstadt has around 160,000 inhabitants, making it th ...
, Germany
* The Science Operations Centre (SOC), located at ESAC, Villanueva de la Cañada
Villanueva de la Cañada is a municipality in the Community of Madrid, Spain. Located 30 km north-west from Madrid, the municipality covers an area of 34.92 km2. Geographically, it sits on a large plain, in which there are several promo ...
, Spain
* The communications network, linking the various remotely located centres and stations to support the operational data traffic
The Science Operations Centre was responsible for mission planning and the generation of payload operations requests to the MOC, as well as science data archiving. The SOC has been operational for the active science phase of the mission, i.e. from the beginning of the Cruise Phase onwards. The handover of payload operations from the MOC to the SOC is performed at the end of the Near-Earth Commissioning Phase (NECP). ESA's Malargüe Station
Malargüe Station (also known as DSA 3 or Deep Space Antenna 3) is a 35-metre ESTRACK radio antenna in Argentina. It enables the European Space Agency (ESA) to communicate with spacecraft in deep space. It is located south of the town of Malargü ...
in Argentina will be used for all operations throughout the mission, with the ground stations of New Norcia Station
New Norcia Station (also known as NNO) is an ESTRACK Earth station in Australia for communication with spacecraft after launch, in low earth orbit, in geostationary orbit and in deep space. It is located south of the town of New Norcia, West ...
, Australia, and Cebreros Station
Cebreros Station (also known as DSA 2 or Deep Space Antenna 2) is a European Space Agency, ESTRACK radio antenna station for communication with spacecraft, located about 10 km east of Cebreros and 90 km from Madrid, Spain, operated by th ...
, Spain, acting as backup when necessary.
During the initial cruise phase, which lasted until November 2021, Solar Orbiter performed two gravity-assist manoeuvres around Venus and one around Earth to alter the spacecraft's trajectory, guiding it towards the innermost regions of the Solar System. At the same time, Solar Orbiter acquired in situ data to characterise and calibrate its remote-sensing instruments. The first close solar pass took place on 26 March 2022 at around a third of Earth's distance from the Sun.[ ]
The spacecraft's orbit has been chosen to be 'in resonance' with Venus, which means that it will return to the planet's vicinity every few orbits and can again use the planet's gravity to alter or tilt its orbit. Initially, Solar Orbiter will be confined to the same plane as the planets, but each encounter of Venus will increase its orbital inclination. For example, after the 2025 Venus encounter, it will make its first solar pass at 17° inclination, increasing to 33° during a proposed mission extension phase, bringing even more of the polar regions into direct view.
Scientific objectives
The spacecraft makes a close approach to the Sun
The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...
every six months. The closest approach will be positioned to allow a repeated study of the same region of the solar atmosphere. ''Solar Orbiter'' will be able to observe the magnetic activity building up in the atmosphere that can lead to powerful solar flare
A solar flare is an intense localized eruption of electromagnetic radiation in the Sun's atmosphere. Flares occur in active regions and are often, but not always, accompanied by coronal mass ejections, solar particle events, and other solar phe ...
s or eruptions.
Researchers will also have the chance to coordinate observations with NASA's ''Parker Solar Probe
The Parker Solar Probe (PSP; previously Solar Probe, Solar Probe Plus or Solar Probe+) is a NASA space probe launched in 2018 with the mission of making observations of the outer corona of the Sun. It will approach to within 9.86 solar radii ...
'' mission (2018-2025) which is performing measurements of the Sun's extended corona
Corona (from the Latin for 'crown') most commonly refers to:
* Stellar corona, the outer atmosphere of the Sun or another star
* Corona (beer), a Mexican beer
* Corona, informal term for the coronavirus SARS-CoV-2, which causes the COVID-19 di ...
.
The objective of the mission is to perform close-up, high-resolution studies of the Sun and its inner heliosphere
The heliosphere is the magnetosphere, astrosphere and outermost atmospheric layer of the Sun. It takes the shape of a vast, bubble-like region of space. In plasma physics terms, it is the cavity formed by the Sun in the surrounding interstell ...
. The new understanding will help answer these questions:
* How and where do the solar wind
The solar wind is a stream of charged particles released from the upper atmosphere of the Sun, called the corona. This plasma mostly consists of electrons, protons and alpha particles with kinetic energy between . The composition of the sola ...
plasma and magnetic field
A magnetic field is a vector field that describes the magnetic influence on moving electric charges, electric currents, and magnetic materials. A moving charge in a magnetic field experiences a force perpendicular to its own velocity and to ...
originate in the corona
Corona (from the Latin for 'crown') most commonly refers to:
* Stellar corona, the outer atmosphere of the Sun or another star
* Corona (beer), a Mexican beer
* Corona, informal term for the coronavirus SARS-CoV-2, which causes the COVID-19 di ...
?
* How do solar transients drive heliospheric variability?
* How do solar eruptions produce energetic particle radiation that fills the heliosphere?
* How does the solar dynamo
The solar dynamo is a physical process that generates the Sun's magnetic field. It is explained with a variant of the dynamo theory. A naturally occurring electric generator in the Sun's interior produces electric currents and a magnetic field ...
work and drive connections between the Sun and the heliosphere?
Instruments
The science payload is composed of 10 instruments:
;
;Heliospheric in-situ instruments (4)
* SWA – Solar Wind Plasma Analyser (United Kingdom): Consists of a suite of sensors that measures the ion and electron bulk properties (including density, velocity, and temperature) of the solar wind, thereby characterizing the solar wind between 0.28 and 1.4 au from the Sun. In addition to determining the bulk properties of the wind, SWA provides measurements of solar wind ion composition for key elements (e.g. the C, N, O group and Fe, Si or Mg)
* EPD – Energetic Particle Detector (Spain): Measures the composition, timing and distribution functions of suprathermal and energetic particles. Scientific topics to be addressed include the sources, acceleration mechanisms, and transport processes of these particles
* MAG – Magnetometer
A magnetometer is a device that measures magnetic field or magnetic dipole moment. Different types of magnetometers measure the direction, strength, or relative change of a magnetic field at a particular location. A compass is one such device, o ...
(United Kingdom): Provides in situ measurements of the heliospheric magnetic field (up to 64Hz) with high precision. This will facilitate detailed studies into the way the Sun's magnetic field links into space and evolves over the solar cycle; how particles are accelerated and propagate around the Solar System, including to the Earth; how the corona and solar wind are heated and accelerated
* RPW – Radio and Plasma Waves (France): Unique amongst the Solar Orbiter instruments, RPW makes both in situ and remote-sensing measurements. RPW measures magnetic and electric fields at high time resolution using a number of sensors/antennas, to determine the characteristics of electromagnetic and electrostatic waves in the solar wind
;
;Solar remote-sensing instruments (6)
* PHI – Polarimetric and Helioseismic Imager (Germany): Provides high-resolution and full-disk measurements of the photospheric vector magnetic field and line-of-sight (LOS) velocity as well as the continuum intensity in the visible wavelength range. The LOS velocity maps have the accuracy and stability to allow detailed helioseismic investigations of the solar interior, in particular of the solar convection zone high-resolution and full-disk measurements of the photospheric magnetic field
* EUI – Extreme Ultraviolet Imager (Belgium): Images the solar atmospheric layers above the photosphere, thereby providing an indispensable link between the solar surface and outer corona that ultimately shapes the characteristics of the interplanetary medium. Also, EUI provides the first-ever UV images of the Sun from an out-of-ecliptic viewpoint (up to 33° of solar latitude during the extended mission phase)
* SPICE – Spectral Imaging of the Coronal Environment (France): Performs extreme ultraviolet imaging spectroscopy to remotely characterize plasma properties of the Sun's on-disk corona. This will enable matching in situ composition signatures of solar wind
The solar wind is a stream of charged particles released from the upper atmosphere of the Sun, called the corona. This plasma mostly consists of electrons, protons and alpha particles with kinetic energy between . The composition of the sola ...
streams to their source regions on the Sun's surface
* STIX – Spectrometer Telescope for Imaging X-rays
The Spectrometer Telescope for Imaging X-rays (STIX) is one of the 10 instruments that are part of the scientific payload for the ESA Solar Orbiter
The Solar Orbiter (SolO) is a Sun-observing satellite developed by the European Space Agency ...
(Switzerland): Provides imaging spectroscopy
Spectroscopy is the field of study that measures and interprets the electromagnetic spectra that result from the interaction between electromagnetic radiation and matter as a function of the wavelength or frequency of the radiation. Matter wa ...
of solar thermal and non-thermal X-ray emission from 4 to 150 keV. STIX provides quantitative information on the timing, location, intensity, and spectra of accelerated electrons as well as of high-temperature thermal plasmas, mostly associated with flares and/or microflares
*Metis – Coronagraph
A coronagraph is a telescopic attachment designed to block out the direct light from a star so that nearby objects – which otherwise would be hidden in the star's bright glare – can be resolved. Most coronagraphs are intended to view t ...
(Italy): Simultaneously images the visible and far ultraviolet emissions of the solar corona and diagnoses, with unprecedented temporal coverage and spatial resolution, the structure and dynamics of the full corona in the range from 1.4 to 3.0 (from 1.7 to 4.1) solar radii from Sun centre, at minimum (maximum) perihelion during the nominal mission. This is a region that is crucial in linking the solar atmospheric phenomena to their evolution in the inner heliosphere
* SoloHI – Solar Orbiter Heliospheric Imager (United States): Images both the quasi-steady flow and transient disturbances in the solar wind over a wide field of view by observing visible sunlight scattered by solar wind electrons. SoloHI provides unique measurements to pinpoint coronal mass ejections (CMEs). (NRL provided)
Institutions involved
The following institutions operate each instrument:
* Solar Wind Plasma Analyser (SWA): Mullard Space Science Laboratory
The UCL Mullard Space Science Laboratory (MSSL) is the United Kingdom's largest university space research group. MSSL is part of the Department of Space and Climate Physics at University College London (UCL), one of the first universities in the ...
* Energetic Particle Detector (EPD): University of Alcala
A university () is an institution of higher (or tertiary) education and research which awards academic degrees in several academic disciplines. Universities typically offer both undergraduate and postgraduate programs. In the United States, the ...
, University of Kiel
Kiel University, officially the Christian-Albrecht University of Kiel, (german: Christian-Albrechts-Universität zu Kiel, abbreviated CAU, known informally as Christiana Albertina) is a university in the city of Kiel, Germany. It was founded in ...
(CAU)
* Magnetometer (MAG): Imperial College London
Imperial College London (legally Imperial College of Science, Technology and Medicine) is a public research university in London, United Kingdom. Its history began with Prince Albert, consort of Queen Victoria, who developed his vision for a cu ...
* Radio and Plasma Waves (RPW): Observatoire de Paris
* Polarimetric and Helioseismic Imager (PHI): Max Planck Institute for Solar System Research
The Max Planck Institute for Solar System Research (abbreviation: MPS; german: Max-Planck-Institut für Sonnensystemforschung) is a research institute in astronomy and astrophysics located in Göttingen, Germany, where it relocated in February 201 ...
(MPS), Instituto de Astrofísica de Andalucía
The Institute of Astrophysics of Andalusia ( es, Instituto de Astrofísica de Andalucía, IAA-CSIC) is a research institute funded by the High Council of Scientific Research of the Spanish government Consejo Superior de Investigaciones Científ ...
(IAA)
* Extreme Ultraviolet Imager (EUI): Royal Observatory of Belgium
The Royal Observatory of Belgium (french: link=no, Observatoire Royal de Belgique, nl, Koninklijke Sterrenwacht van België), has been situated in the Uccle municipality of Brussels (Belgium) since 1890. It was first established in Saint-Josse ...
, Centre Spatial de Liège
Center or centre may refer to:
Mathematics
* Center (geometry), the middle of an object
* Center (algebra), used in various contexts
** Center (group theory)
** Center (ring theory)
* Graph center, the set of all vertices of minimum eccentrici ...
, Institut d'astrophysique spatiale
The Institut d'astrophysique spatiale (IAS; English: Institute of Space Astrophysics) is a French research institute supporting advanced research in aerospace and astrophysics. It is located in Orsay, just south of Paris. It is a public resear ...
, Max Planck Institute for Solar System Research
The Max Planck Institute for Solar System Research (abbreviation: MPS; german: Max-Planck-Institut für Sonnensystemforschung) is a research institute in astronomy and astrophysics located in Göttingen, Germany, where it relocated in February 201 ...
(MPS)
* Spectral Imaging of the Coronal Environment (SPICE): Institut d'astrophysique spatiale
The Institut d'astrophysique spatiale (IAS; English: Institute of Space Astrophysics) is a French research institute supporting advanced research in aerospace and astrophysics. It is located in Orsay, just south of Paris. It is a public resear ...
Rutherford Appleton Laboratory
The Rutherford Appleton Laboratory (RAL) is one of the national scientific research laboratories in the UK operated by the Science and Technology Facilities Council (STFC). It began as the Rutherford High Energy Laboratory, merged with the Atlas ...
, Max Planck Institute for Solar System Research
The Max Planck Institute for Solar System Research (abbreviation: MPS; german: Max-Planck-Institut für Sonnensystemforschung) is a research institute in astronomy and astrophysics located in Göttingen, Germany, where it relocated in February 201 ...
(MPS)
* Spectrometer/Telescope for Imaging X-rays (STIX): FHNW, Space Research Centre of Polish Academy of Sciences
The Space Research Centre (SRC, pl, Centrum Badań Kosmicznych) is an interdisciplinary research institute of the Polish Academy of Sciences. It was established in 1977. SRC PAS is the only institute in Poland whose activity is fully dedicated ...
, Leibniz-Institut für Astrophysik Potsdam (AIP)
* Coronagraph (Metis): University of Florence
The University of Florence (Italian: ''Università degli Studi di Firenze'', UniFI) is an Italian public research university located in Florence, Italy. It comprises 12 schools and has around 50,000 students enrolled.
History
The first universi ...
, INAF
The National Institute for Astrophysics ( it, Istituto Nazionale di Astrofisica, or INAF) is an Italian research institute in astronomy and astrophysics, founded in 1999. INAF funds and operates twenty separate research facilities, which in turn ...
, Max Planck Institute for Solar System Research
The Max Planck Institute for Solar System Research (abbreviation: MPS; german: Max-Planck-Institut für Sonnensystemforschung) is a research institute in astronomy and astrophysics located in Göttingen, Germany, where it relocated in February 201 ...
(MPS)
* Heliospheric Imager (SoloHI): United States Naval Research Laboratory
The United States Naval Research Laboratory (NRL) is the corporate research laboratory for the United States Navy and the United States Marine Corps. It was founded in 1923 and conducts basic scientific research, applied research, technological ...
Launch and flight
Launch delays
In April 2015, the launch was set back from July 2017 to October 2018. In August 2017, Solar Orbiter was considered "on track" for a launch in February 2019. The launch occurred on 10 February 2020 on an Atlas V
Atlas V is an expendable launch system and the fifth major version in the Atlas (rocket family), Atlas launch vehicle family. It was originally designed by Lockheed Martin, now being operated by United Launch Alliance (ULA), a joint venture be ...
411.
Launch
The Atlas V 411 (AV-087) lifted off from SLC-41 at Cape Canaveral, Florida, at 04:03 UTC. The Solar Orbiter spacecraft separated from the Centaur upper stage nearly 53 minutes later, and the European Space Agency acquired the first signals from the spacecraft a few minutes later.
Trajectory
After launch, Solar Orbiter will take approximately 3.5 years, using repeated gravity assist
In orbital mechanics and aerospace engineering, a gravitational slingshot, gravity assist maneuver, or swing-by is the use of the relative movement (e.g. orbit around the Sun) and gravity of a planet or other astronomical object to alter the p ...
s from Earth and Venus, to reach its operational orbit, an elliptical orbit with perihelion 0.28 AU and aphelion 0.91 AU. The first flyby was of Venus in December 2020. Over the expected mission duration of 7 years, it will use additional gravity assists from Venus to raise its inclination from 0° to 24°, allowing it a better view of the Sun's poles. If an extended mission is approved, the inclination could rise further to 33°.
During its cruise phase to Venus, Solar Orbiter passed through the ion tail of Comet C/2019 Y4 (ATLAS) from 31 May to 1 June 2020. It passed through the comet's dust tail on 6 June 2020.
In June 2020, Solar Orbiter came within of the Sun, and captured the closest pictures of the Sun ever taken.
Mission timeline
* April 2012: €319 million contract to build orbiter awarded to Astrium UK
* June 2014: Solar shield completes 2 week bake test
* September 2018: Spacecraft is shipped to IABG
IABG (Industrieanlagen-Betriebsgesellschaft mbH) is a German analysis and test engineering company based in Taufkirchen near Munich.
History
The company was founded in 1961 on the initiative of the federal government as a central analysis and ...
in Germany to begin the environmental test campaign
* February 2020: Successful launch
* May-June 2020: Encounter with the ion and dust tails of C/2019 Y4 (ATLAS)
*Jul 2020: First images of the Sun released
*March 2022: highest resolution image of the Sun’s full disc and outer atmosphere, the corona, ever taken
*September 2022: Solar Orbiter solves magnetic switchback mystery
See also
*
*
*
*
*
*
*
*
*
* ''Ulysses
Ulysses is one form of the Roman name for Odysseus, a hero in ancient Greek literature.
Ulysses may also refer to:
People
* Ulysses (given name), including a list of people with this name
Places in the United States
* Ulysses, Kansas
* Ulysse ...
'' spacecraft
* WIND
Wind is the natural movement of air or other gases relative to a planet's surface. Winds occur on a range of scales, from thunderstorm flows lasting tens of minutes, to local breezes generated by heating of land surfaces and lasting a few hou ...
spacecraft
References
External links
New ESA Solar Orbiter homepage (from December 2020)
Old ESA Solar Orbiter homepage (to December 2020)
Special issue on "The Solar Orbiter Mission"
in '' Astronomy & Astrophysics''
Solar Orbiter at eoPortal
METIS instrument homepage
Media Kit - overview of mission
{{Portal bar, Spaceflight
Missions to the Sun
European Space Agency space probes
Solar space observatories
NASA space probes
Solar telescopes
Space probes launched in 2020
Living With a Star
Cosmic Vision
Spacecraft launched by Atlas rockets
February 2020 events in the United States