Aditya L1 ( sa, आदित्य, lit: Sun, ) is a planned
coronagraphy spacecraft to study
solar atmosphere
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 ...
, currently being designed and developed by
Indian Space Research Organisation
The Indian Space Research Organisation (ISRO; ) is the national space agency of India, headquartered in Bengaluru. It operates under the Department of Space (DOS) which is directly overseen by the Prime Minister of India, while the Chairman ...
(ISRO) and various other Indian research institutes.
It will be inserted in a
halo orbit
A halo orbit is a periodic, three-dimensional orbit near one of the L1, L2 or L3 Lagrange points in the three-body problem of orbital mechanics. Although a Lagrange point is just a point in empty space, its peculiar characteristic is that it ca ...
around the
L1 point between
Earth
Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...
and
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 ...
where it will study solar atmosphere,
solar magnetic storms and its impact on environment around Earth.
The spacecraft will study
coronal heating
A corona ( coronas or coronae) is the outermost layer of a star's atmosphere. It consists of plasma.
The Sun's corona lies above the chromosphere and extends millions of kilometres into outer space. It is most easily seen during a total solar ...
,
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 ...
acceleration, coronal
magnetometry
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, ...
, origin and monitoring of near-UV solar radiation and continuously observe
photosphere
The photosphere is a star's outer shell from which light is radiated.
The term itself is derived from Ancient Greek roots, φῶς, φωτός/''phos, photos'' meaning "light" and σφαῖρα/''sphaira'' meaning "sphere", in reference to it ...
,
chromosphere
A chromosphere ("sphere of color") is the second layer of a star's atmosphere, located above the photosphere and below the solar transition region and corona. The term usually refers to the Sun's chromosphere, but not exclusively.
In the Su ...
and
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 ...
,
solar energetic particles
Solar energetic particles (SEP), formerly known as solar cosmic rays, are high-energy, charged particles originating in the solar atmosphere and solar wind. They consist of protons, electrons and heavy ions with energies ranging from a few ten ...
and magnetic field of the Sun.
First dedicated Indian mission to observe Sun, it is planned to be launched in March 2023 aboard a
PSLV-XL
The Polar Satellite Launch Vehicle (PSLV) is an expendable medium-lift launch vehicle designed and operated by the Indian Space Research Organisation (ISRO). It was developed to allow India to launch its Indian Remote Sensing (IRS) satellites ...
launch vehicle.
History
Aditya was conceptualised in January 2008 by the Advisory Committee for Space Research. It was initially envisaged as a small , low-Earth orbiting satellite with a
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 ...
to study the
solar corona
A corona ( coronas or coronae) is the outermost layer of a star's atmosphere. It consists of plasma.
The Sun's corona lies above the chromosphere and extends millions of kilometres into outer space. It is most easily seen during a total solar e ...
. An experimental budget of 3 Crore
INR was allocated for the financial year 2016–2017.
The scope of the mission has since been expanded and it is now planned to be a comprehensive solar and space environment observatory to be placed at the
Lagrange point
In celestial mechanics, the Lagrange points (; also Lagrangian points or libration points) are points of equilibrium for small-mass objects under the influence of two massive orbiting bodies. Mathematically, this involves the solution of th ...
L1, so the mission was renamed "Aditya-L1". , the mission has an allocated cost of ₹378.53
crore
A crore (; abbreviated cr) denotes ten million (10,000,000 or 107 in scientific notation) and is equal to 100 lakh in the Indian numbering system. It is written as 1,00,00,000 with the local 2,2,3 style of digit group separators (one lakh is e ...
excluding launch costs.
Overview
![Lagrange-better](https://upload.wikimedia.org/wikipedia/commons/9/96/Lagrange-better.png)
The Aditya-L1 mission will take around 109 Earth days after launch to reach the
halo orbit
A halo orbit is a periodic, three-dimensional orbit near one of the L1, L2 or L3 Lagrange points in the three-body problem of orbital mechanics. Although a Lagrange point is just a point in empty space, its peculiar characteristic is that it ca ...
around the
L1 point, which is about from Earth. The satellite carries seven science payloads with diverse objectives, including but not limited to, the
coronal heating
A corona ( coronas or coronae) is the outermost layer of a star's atmosphere. It consists of plasma.
The Sun's corona lies above the chromosphere and extends millions of kilometres into outer space. It is most easily seen during a total solar ...
,
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 ...
acceleration, coronal magnetometry, origin and monitoring of near-UV solar radiation (which drives Earth's upper atmospheric dynamics and global climate), coupling of the solar photosphere to chromosphere and corona, in-situ characterisations of the space environment around Earth by measuring energetic particle fluxes and magnetic fields of the solar wind and
solar magnetic storms that have adverse effects on space and ground-based technologies.
Aditya-L1 will be able to provide observations of Sun's
photosphere
The photosphere is a star's outer shell from which light is radiated.
The term itself is derived from Ancient Greek roots, φῶς, φωτός/''phos, photos'' meaning "light" and σφαῖρα/''sphaira'' meaning "sphere", in reference to it ...
,
chromosphere
A chromosphere ("sphere of color") is the second layer of a star's atmosphere, located above the photosphere and below the solar transition region and corona. The term usually refers to the Sun's chromosphere, but not exclusively.
In the Su ...
and
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 ...
. In addition, an instrument will study the
solar energetic particles
Solar energetic particles (SEP), formerly known as solar cosmic rays, are high-energy, charged particles originating in the solar atmosphere and solar wind. They consist of protons, electrons and heavy ions with energies ranging from a few ten ...
' flux reaching the L1 orbit, while a
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 ...
payload will measure the variation in
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 ...
strength at the halo orbit around L1. These payloads have to be placed outside the interference from the Earth's magnetic field and hence could not have been useful in the low Earth orbit as proposed on the original Aditya mission concept.
One of the major unsolved issues in the field of
solar physics
Solar physics is the branch of astrophysics that specializes in the study of the Sun. It deals with detailed measurements that are possible only for our closest star. It intersects with many disciplines of pure physics, astrophysics, and compu ...
is that the upper atmosphere of the Sun is hot whereas the lower atmosphere is just . In addition, it is not understood how exactly the Sun's radiation affects the dynamics of the Earth's atmosphere on shorter as well as on longer time scale. The mission will obtain near simultaneous images of the different layers of the Sun's atmosphere, which reveal the ways in which the energy may be channeled and transferred from one layer to another. Thus the Aditya-L1 mission will enable a comprehensive understanding of the dynamical processes of the Sun and address some of the outstanding problems in solar physics and
heliophysics
Heliophysics (from the prefix " helio", from Attic Greek ''hḗlios'', meaning Sun, and the noun "physics": the science of matter and energy and their interactions) is the physics of the Sun and its connection with the Solar System. NASA define ...
.
Payloads
* Visible Emission Line Coronagraph (VELC): The
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 ...
creates an artificial total solar eclipse in space by blocking the sunlight by an occultor. This telescope will have capabilities of
spectral imaging
Spectral imaging is imaging that uses multiple bands across the electromagnetic spectrum. While an ordinary camera captures light across three wavelength bands in the visible spectrum, red, green, and blue (RGB), spectral imaging encompasses ...
of the corona in visible and infra-red wavelengths. The objectives are to study the diagnostic parameters of solar corona and dynamics and origin of
coronal mass ejection
A coronal mass ejection (CME) is a significant release of plasma and accompanying magnetic field from the Sun's corona into the heliosphere. CMEs are often associated with solar flares and other forms of solar activity, but a broadly accepted ...
s (using three visible and one infra-red channels); magnetic field measurements of the solar corona down to tens of
Gauss
Johann Carl Friedrich Gauss (; german: Gauß ; la, Carolus Fridericus Gauss; 30 April 177723 February 1855) was a German mathematician and physicist who made significant contributions to many fields in mathematics and science. Sometimes refer ...
. Additional objectives are to determine why the solar atmosphere is so hot, and how the changes in the Sun can affect
space weather
Space weather is a branch of space physics and aeronomy, or heliophysics, concerned with the time varying conditions within the Solar System, including the solar wind, emphasizing the space surrounding the Earth, including conditions in the ma ...
and Earth's climate. The VELC payload weighs nearly .
** PI Institute:
Indian Institute of Astrophysics
The Indian Institute of Astrophysics (IIA), with its headquarters in Bengaluru,is an autonomous Research Institute wholly financed by the department of Science and Technology, Government of India. IIA conducts research primarily in the areas of ...
(IIA)
* Solar Ultraviolet Imaging Telescope (SUIT): SUIT will observe the Sun between 200-400 nm wavelength range and it will provide full disk images of different layers of the solar atmosphere by making use of 11 filters. The Sun has never been observed from space in this wavelength range. The spacecraft being at the first Lagrange point, SUIT shall be observing the Sun continuously without interruption. The instrument is being developed under the leadership of A. N. Ramaprakash and Durgesh Tripathi from
Inter-University Centre for Astronomy and Astrophysics
The Inter-University Centre for Astronomy and Astrophysics (IUCAA) is an autonomous institution set up by the University Grants Commission of India to promote nucleation and growth of active groups in astronomy and astrophysics in Indian univer ...
(IUCAA) at
Pune
Pune (; ; also known as Poona, (List of renamed Indian cities and states#Maharashtra, the official name from 1818 until 1978) is one of the most important industrial and educational hubs of India, with an estimated population of 7.4 million ...
, in collaboration with ISRO and other institutes. The SUIT payload weighs nearly .
** PI Institute:
Inter-University Centre for Astronomy and Astrophysics
The Inter-University Centre for Astronomy and Astrophysics (IUCAA) is an autonomous institution set up by the University Grants Commission of India to promote nucleation and growth of active groups in astronomy and astrophysics in Indian univer ...
(IUCAA), Pune
** Co-I Institutes:
Indian Institute of Astrophysics
The Indian Institute of Astrophysics (IIA), with its headquarters in Bengaluru,is an autonomous Research Institute wholly financed by the department of Science and Technology, Government of India. IIA conducts research primarily in the areas of ...
(IIA),
Center of Excellence in Space Sciences India (CESSI)-IISER Kolkata.
* Aditya Solar wind Particle Experiment (ASPEX): To study the variation and properties of 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 ...
as well as its distribution and spectral characteristics.
** PI Institute:
Physical Research Laboratory
The Physical Research Laboratory (PRL) is a National Research Institute for space and allied sciences, supported mainly by Department of Space, Government of India. This research laboratory has ongoing research programmes in astronomy and astrop ...
(PRL)
* Plasma Analyser Package for Aditya (PAPA): To understand the composition of solar wind and its energy distribution.
** PI Institute: Space Physics Laboratory (SPL),
VSSC
The Vikram Sarabhai Space Centre (VSSC) is a major space research centre of the Indian Space Research Organisation (ISRO), focusing on rocket and space vehicles for India's satellite programme. It is located in Thiruvananthapuram, in the Indi ...
* Solar Low Energy X-ray Spectrometer (SoLEXS): To monitor the
X-ray flares for studying the enigmatic
coronal heating
A corona ( coronas or coronae) is the outermost layer of a star's atmosphere. It consists of plasma.
The Sun's corona lies above the chromosphere and extends millions of kilometres into outer space. It is most easily seen during a total solar ...
mechanism of the solar corona.
** PI Institute:
ISRO Satellite centre
The U R Rao Satellite Centre (URSC), formerly ISRO Satellite Centre (ISAC) ( hi, इसरो उपग्रह केंद्र) is an Indian Space Research Organisation centre for the design, development, and construction of Indian satel ...
(ISAC)
* High Energy L1 Orbiting X-ray Spectrometer (HEL1OS): To observe the dynamic events in the solar corona and provide an estimate of the energy used to accelerate the
solar energetic particles
Solar energetic particles (SEP), formerly known as solar cosmic rays, are high-energy, charged particles originating in the solar atmosphere and solar wind. They consist of protons, electrons and heavy ions with energies ranging from a few ten ...
during the eruptive events.
** PI Institutes: ISRO Satellite Centre (ISAC) and
Udaipur Solar Observatory (USO), PRL
* Magnetometer:
To measure the magnitude and nature of the
interplanetary magnetic field
The interplanetary magnetic field (IMF), now more commonly referred to as the heliospheric magnetic field (HMF), is the component of the solar magnetic field that is dragged out from the solar corona by the solar wind flow to fill the Solar Syst ...
.
** PI Institute: Space Physics Laboratory (SPL) and VSSC,
Laboratory for Electro-Optics Systems
Laboratory for Electro-Optics Systems is a research lab belonging to Indian Space Research Organisation. It involves in design and development of optics and sensor modules that can be deployed either onboard satellite or with the launch vehicle.
...
(LEOS) and ISAC
See also
*
Lagrange point
In celestial mechanics, the Lagrange points (; also Lagrangian points or libration points) are points of equilibrium for small-mass objects under the influence of two massive orbiting bodies. Mathematically, this involves the solution of th ...
*
Solar space missions
*
Solar Orbiter
The Solar Orbiter (SolO) is a Sun-observing satellite developed by the European Space Agency (ESA). SolO, designed to obtain detailed measurements of the inner heliosphere and the nascent solar wind, will also perform close observations of th ...
References
External links
*
{{Future spaceflights
Satellites of India
2023 in spaceflight
2023 in India
Missions to the Sun