Why ISRO’s Aditya L-1 mission is unique in many ways

  • August 22, 2023
  • Posted by: OptimizeIAS Team
  • Category: DPN Topics
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Why ISRO’s Aditya L-1 mission is unique in many ways

Subject :Science and technology

Section: Space technology

Context:

  • ISRO’s Aditya L-1 mission, the Indian space agency’s most complex mission ever, is scheduled to launch by the end of August or early September.

Why is it unique?

  • For the first time,India is building a ‘space observatory’ — the spacecraft that will be peering at the Sun all the time, checking out the ball of fire 24×7.
  • India hasnever put a spacecraft at a Lagrange point.
    • Lagrange point is a point between two or more massive objects (like the Sun and the Earth) where the massive objects exert equal pull over the spacecraft so that it “stays” right there.
    • There are five Lagrange points in the Sun-Earth system;Aditya is going to be positioned at Lagrange-1.
  • There are 7 instruments onboard Aditya L-1. The two principal instruments are completely designed and built by Indian scientists at Inter-University Centre for Astronomy and Astrophysics (IUCAA), Pune.
  1. SUIT (Solar Ultraviolet Imaging Telescope)
    • The Sun is not solid like the Earth is, but a huge ball of gas with different layers, all surrounded by the corona.
    • Each layer spins at a different speed.
    • SUIT will simultaneously map different parts of the Sun — photosphere and chromosphere of the Sun using 11 filterssensitive to different wavelengths and covering different heights in the solar atmosphere.
    • This will help in the understanding of the processes involved in the transfer from mass and energy from one layer to the other.
  2. VELC (Visible Emission Line Coronagraph):
    • The VELC will study the corona.
    • It will do both photography (optical imaging) and spectrograph, which is splitting of light into its constituent wavelengths — a study of the spectrographic lines can tell a lot about the sun.
    • This is a unique experiment, because this has never been done by anybody from space.
    • The VELC can investigate the red and green spectroscopic lines, which give a peek into the temperature of the region of the Sun from where the light has come.
    • The VELC will do ‘spectropolarimetric measurements’ to study the magnetic field of the Sun — for the first time by any country from space.
  • The other five instruments pick up and analyse X-rays and particles from the Sun.

Broad comparison of SUIT and VELC:

  • The SUIT will be looking at the disc of the Sun, which comprises the inner photosphere and the outer chromosphere, while the VELC will peer into the rim (corona).
  • The SUIT will capture the near-ultraviolet rays (200-400 nm wavelength) coming from the Sun; VELC will pick up the near-Infra red radiation from the Sun.

Payloads along with their major capability of scientific investigation

TypePayloadCapability
Remote Sensing Payloads1. Visible Emission Line Coronagraph(VELC)
  • Corona/Imaging & Spectroscopy
2. Solar Ultraviolet Imaging Telescope (SUIT)
  • Photosphere and Chromosphere Imaging- Narrow & Broadband
3. Solar Low Energy X-ray Spectrometer (SoLEXS)
  • Soft X-ray spectrometer: Sun-as-a-star observation
4. High Energy L1 Orbiting X-ray Spectrometer(HEL1OS)
  • Hard X-ray spectrometer: Sun-as-a-star observation
In-situ Payloads5. Aditya Solar wind Particle Experiment(ASPEX)
  • Solar wind/Particle Analyzer Protons & Heavier Ions with directions
6. Plasma Analyser Package For Aditya (PAPA)
  • Solar wind/Particle Analyzer Electrons & Heavier Ions with directions
7.  Advanced Tri-axial High Resolution Digital Magnetometers
  • In-situ magnetic field (Bx, By and Bz).

Why the interest in the Sun? 

  • The Aditya L-1 spacecraft is essentially a space telescope.
  • The Aditya L-1 mission has two purposes — long term (scientific quest) and short term (protecting our satellites).
  • The genesis of this project was in 2006, when scientists from Indian Institute of Astrophysics and the Astronomical Society of India showed concern about protecting the satellites from harmful effects of the sun’s emissions.
  • Prof U. R. Rao, a former Chairman of ISRO, suggested that an spacecraft can be placed at Lagrange-1 point fro observation of the sun.
  • Main idea behind it was:
    • To provide an early warning against solar storms that can damage satellites and electric grids
    • Coronal mass ejections (billions of tons of matter flung out of the Sun)
    • Solar flares (Sudden burst of energy from sun contains X-rays, electromagnetic waves or high-energy particles) that can disrupt radio communications and harm astronauts.
  • Long term goals include monitoring the UV-rays.
    • Ultraviolet rays (UV rays) from the Sun can impact climate on the Earth and the ozone layer in the atmosphere.
    • UV radiation of wavelengths between 200 and 310 nanometres is absorbed by the oxygen and ozone in the Earth’s atmosphere.
    • UV radiation above 310 nm pierces through the atmosphere.
    • We need to know what kind of UV the Sun is likely to emit.
    • Changes in UV radiation can influence cloud formation, water vapor content and temperature patterns in the Earth’s lower atmosphere.

Why Lagrange point 1 (L1)?

  • The L-1 point lies between the Sun and the Earth, affording a spacecraft placed there an excellent view of the Sun.
  • L-1 (along with L-2 and L-3) are ‘halo orbits’, where a spacecraft placed there keeps going round an invisible center.
  • An object kept there is very unstable, because the spacecraft is subject to constant pulls and pushes in space.
  • Placing a satellite at L-1 is tough and keeping it there is even tougher, but L-1 has a vantage point for excellent observation of the Sun’s activity.
Science and tech Why ISRO’s Aditya L-1 mission is unique in many ways