Satellite space junk bad for environment

Context: More than 10,000 active satellites are in orbit around
the planet today. This number is estimated to shoot up to more than 100,000 by
2030’s and possibly half a million in the in the decades to follow. Most
satellites, at the end of their lifecycle, fall to a fiery death through earth’s
atmosphere. While disintegrating in the upper atmosphere, they leave all kinds
of pollutants. With the increase of number of these satellites, the level of
pollution also goes up. Scientists are particularly concerned about the impact
of this pollution on the ozone layer in Earth’s stratosphere. This layer
absorbs up to 99% of the ultraviolet rays from the sun, which would otherwise
harm living organisms on Earth’s surface, but the pollutants from the burnt-up space
junk are harming it.

Key points

·      
Space
Debris: It is also known as space
junk, which is any piece of machinery or debris left in space by humans. It can
refer to large objects such as dead satellites and smaller items, such as
debris or paint flecks that have fallen off a rocket. Many space debris consist
of rocket-launching material and decommissioned satellites. Most of the debris
is in the Low Earth Orbit (LEO), within 2,000 kilometres of the Earth's
surface, though some are in the Geostationary Orbit (35,786 kilometres above
the Equator).

Current Status - As per ESA's Space Environment Report over 30,000 pieces of space
debris have been recorded and are being tracked on a regular basis by space
surveillance networks. There were approximately 6,718 active satellites
orbiting the Earth in 2022, an increase of nearly 2,000 satellites in just one
year.

·      
Causes for
Space Debris: Space
debris has become an increasing problem in Earth's orbit due to increased human
activities in space. The following are the causes of the rise in space debris:

Launching objects into Space - The space debris issue
has intensified due to the rapid increase in the number of satellites launched
into space.

Abandoned satellites - Some satellites are decommissioned and become defunct after their
functional operations, and they end up as part of the growing collection of
space junk.

Anti-satellite tests - Several countries, such as the USA, China, and India, have conducted
anti-satellite tests, using missiles to destroy their own satellites. This has
led to deliberate space debris creation.

Increasing expansion - The space industry is booming, with both public and private sectors
investing heavily in space exploration.

Long-lasting mission debris - Space debris caused by satellite missions in LEO
might return to the atmosphere of the Earth. However, debris at higher
altitudes, like geostationary orbits, can orbit the Earth for a longer period.

Fragmentation of space debris - One of the significant factors responsible for the
rise in space debris is the fragmentation of space debris due to collision,
explosion and degradation.

·      
Space
pollution: The accumulation of space
debris in Earth's orbit contributes to long-term orbital pollution, which not
only complicates space activities but also raises environmental concerns for
future generations of space explorers.

·      
Initiatives
for Space Debris Removal by India: Space debris is a critical issue for the safety of operating satellites
and the long-term sustainability of space activities. Some initiatives to deal
with space debris include

ISRO System for Safe & Sustainable Operations
Management (IS4OM) - Launched
in 2022, it is ISRO's holistic approach to ensuring the safety of space assets
and the continued use of outer space for national development. It monitors
objects that pose collision threats.

Project Netra (Network for Space Object Tracking and
Analysis) - It is an early warning system
launched by ISRO in space to detect debris and other threats to Indian
satellites. It can spot, track, and catalogue objects as small as 10 cm, up to
a range of 3,400 km.

Collision Avoidance Manoeuvres - To avoid collisions with other space objects, ISRO
performed 21 collision avoidance manoeuvres of Indian operational space assets
in 2022.

ISRO SSA (Space Situational Awareness) Control Centre
- It was established in 2020 to
function as a hub of all space situational awareness activities within India,
to ensure safe and sustainable space operations.

·      
Way
forward: Tackling the issue of space
debris removal is a complex and multifaceted challenge that requires a
combination of technological, regulatory, and international cooperation
measures.

Enhanced awareness - To effectively remove space debris, there is a need to upgrade
observation technology and enhance the accuracy of tracking models, which will
enable more precise monitoring and identification of space debris and objects
in orbit.

Debris mitigation and active removal - It involves collecting and moving defunct or non-manoeuvrable
debris to lower orbits, where it can naturally deorbit more quickly. Various
technologies, such as harpoons, magnets, lasers, and slingshots, are being
explored as potential means to capture space debris.