Assessment of space situation done to ensure safety of AdityaL1

Subject :Science and Technology

Section: Space technology

Context:

While the Indian Space Research Organisation’s (ISRO) Aditya-L1 spacecraft is on its way towards the Sun-Earth Lagrange’s Point 1 (L1), the space agency has done an assessment of the space situation around L1 to ensure safety of the spacecraft.

Space situation Assessment (SSA):

SSA deals with the comprehensive knowledge of the space environment, assessment of any threats to space activities and the implementation of necessary mitigation measures to safeguard the space assets. SSA plays a crucial role in ensuring safe and sustainable space activities complying with domestic and international guidelines, standards and other norms.

Aditya L1 mission:

Aditya-L1 is India’s first mission dedicated to studying the Sun. The spacecraft commenced its journey L1, on September 18 and is expected to reach L1 by January 2024.
Aditya-L1 will operate in a halo orbit around the Sun-Earth L1 point, located approximately 1.5 million kilometers from Earth.
- Halo orbits are periodic, three-dimensional orbits around a Lagrange Point (L1, L2 or L3) and involve an out-of-plane motion component relative to the primary bodies. The orbit is large enough in size to be continuously viewed from Earth and would appear to form a halo around the Lagrange Points (here L1 for Aditya L1).

There are currently four operational spacecraft at L1- WIND, Solar and Heliospheric Observatory (SOHO), Advanced Composition Explorer (ACE) and Deep Space Climate Observatory (DSCOVER).
These spacecraft at L1 provide vital early warnings on adverse space weather events that help protect orbiting space assets and ground-based infrastructure.

Science Objectives of Aditya L1 mission:

Study of Solar upper atmospheric (chromosphere and corona) dynamics.
Study of chromospheric and coronal heating, physics of the partially ionized plasma, initiation of the coronal mass ejections, and flares
Observe the in-situ particle and plasma environment providing data for the study of particle dynamics from the Sun.
Physics of solar corona and its heating mechanism.
Diagnostics of the coronal and coronal loops plasma: Temperature, velocity and density.
Development, dynamics and origin of CMEs.
Identify the sequence of processes that occur at multiple layers (chromosphere, base and extended corona) which eventually leads to solar eruptive events.
Magnetic field topology and magnetic field measurements in the solar corona .
Drivers for space weather (origin, composition and dynamics of solar wind .

Source: TH, ISRO