Space debris include litter constituting of defunct man-made objects in the outer space including, old satellites, disintegrated fragments of satellites and spent rocket stages. They are classified on the basis of their velocity, size and altitude.
ISRO has made major strides in recent times capitalizing on the ability of its Polar Satellite Launch Vehicles (PSLV) to launch massive payloads.
It most recently completed the successful launch of the sixth Cartosat satellite along with 30 nano-satellites.
Along with launching satellites, safeguarding space assets from debris is also a major priority for the agency.
How does the ISRO plan on doing this?
23 Jun 2017: How does ISRO protect its assets from space debris?
About: What are space debris?
Space debris include litter constituting of defunct man-made objects in the outer space including, old satellites, disintegrated fragments of satellites and spent rocket stages. They are classified on the basis of their velocity, size and altitude.
About 29,000 large debris, 6,70,000 debris between 1-10cm and 170 million debris smaller than 1 cm were estimated to be floating in outer space as of July 2013.
Danger: Debris troubles
Collision with even the tiniest of debris may destroy a satellite. Collision may have a sandblasting effect particularly on solar panels and optical devices which are not protected by the Whipple shield, designed to protect spacecrafts from collision.
Satellites can avoid collision with early warning by shifting position. However, this costs fuel and reduces the operational life of the satellite.
Details: How does ISRO deal with space debris?
ISRO is a member of the Inter-Agency Space Debris Coordination Committee, an international body with space agencies as members, which alerts respective space agencies when their satellites are in the path of debris.
It further uses its Multi-Object Tracking Radar (MOTR), operational since 2015 to safeguard its assets.
ISRO also contributes to reducing space debris by using a single rocket for launching multiple satellites.
Tracking & monitoring: How does this work?
ISRO monitors its satellites 24×7 to avoid the possibility of them colliding with space debris.
The MOTR can further spot objects of size 30 cm x 30 cm at an 800 km and objects of the dimension 50 cm x 50 cm at a distance of 1000 km.
Using a single rocket for multiple satellites further avoids multiple rockets being added to space junk.
Fact: ISRO’s mechanism to avoid space debris from used rockets
A rocket is useless after the fourth stage of launching a satellite. It contains traces of propellant and can form dangerous space debris if it explodes. ISRO uses a mechanism “to automatically deactivate and de-pressurize the rocket”, once it places the satellite in the orbit.