All About The Aditya – L1, India’s First Mission to Study The Sun


Indian Space Research Organisation (ISRO) plans to study the Sun through its Aditya-L1 satellite which will be inserted in a halo orbit, which is 1.5 million km from the Earth during 2019-2020.

Aditya-L1 will be launched by PSLV-XL from Sriharikota in Andhra Pradesh.  Aditya-L1 mission, is a satellite designed to study the solar corona (outer layers of the Sun) which is quite similar to NASA’s Parker Solar Probe.

According to the ISRO,

  • The satellite was conceived as a 400 kg class satellite carrying just one payload, the Visible Emission Line Coronagraph (VELC).
  • It was planned to be launched in an 800 km low earth orbit.
  • The Aditya – L1 will be inserted in a halo orbit around the Lagrangian point 1 (L1), which is 1.5 million km from the Earth.Lagrangian point is a point where the attraction by the Sun and the Earth becomes equal.
  • The satellite will perform additional experiments and will also observe the Sun’s Photosphere and the Chromosphere.
  • Aditya – L1 will have six additional payloads.

Particle payloads will study the particle flux emanating from the Sun and reaching the L1 orbit, and the magnetometer payload will measure the variation in magnetic field strength at the halo orbit around L1. The main payload continues to be the coronagraph with improved capabilities. The complete list of payloads, their science objective and lead institute for developing the payload is provided below

  • Visible Emission Line Coronagraph (VELC): To study the diagnostic parameters of solar corona and dynamics and origin of Coronal Mass Ejections (3 visible and 1 Infra-Red channels); magnetic field measurement of solar corona down to tens of Gauss – Indian Institute of Astrophysics (IIA)
  • Solar Ultraviolet Imaging Telescope (SUIT): To image the spatially resolved Solar Photosphere and Chromosphere in near Ultraviolet (200-400 nm) and measure solar irradiance variations – Inter-University Centre for Astronomy & Astrophysics (IUCAA)
  • Aditya Solar wind Particle Experiment (ASPEX) : To study the variation of solar wind properties as well as its distribution and spectral characteristics – Physical Research Laboratory (PRL)
  • Plasma Analyser Package for Aditya (PAPA) : To understand the composition of solar wind and its energy distribution – Space Physics Laboratory (SPL), VSSC
  • Solar Low Energy X-ray Spectrometer (SoLEXS) : To monitor the X-ray flares for studying the heating mechanism of the solar corona – ISRO Satellite Centre (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 particles during the eruptive events – ISRO Satellite Centre (ISAC)and Udaipur Solar Observatory (USO), PRL
  • Magnetometer: To measure the magnitude and nature of the Interplanetary Magnetic Field – Laboratory for Electro-optic Systems (LEOS) and ISAC.

With the inclusion of multiple payloads, the Aditya-L1 mission will ensure that solar scientists from several Indian institutions are able to participate in space-based instrumentation and observations.