RAJYA SABHA TV IN DEPTH: SPACE DEBRIS
PRELIMS: Current events of national and international importance, General Science)
MAINS: GENERAL STUDIES III – Science and Technology)
On March 27th 2019, India has successfully tested a state-of-the art missile technology by shooting down its own satellite parked at Low Earth Orbit (LEO) under “Mission Shakti”. The anti-satellite test placed the country in elite group of countries (US, Russia and China) with such a capability.
But the NASA has said that the debris created due to this has increased the risk to international space station (ISS).
India, on the other hand, has said that the test was conducted is well within 300 km range while ISS orbits the earth at an altitude of 330-435 km. The little debris created would fall back to earth within weeks.
- A SPACE DEBRIS may refer to a natural debris found in the solar system (asteroids, comets and meteoroids) or debris from the mass of defunct, artificially created objects (like old satellites and spent rocket stages) in space, especially earth orbit.
- Collision with debris can create a hazard to a spacecraft by damaging its solar panels, optics, etc due to its extremely high speed. Momentum is directly proportional to velocity and a high momentum creates a large force of impact.
- Space debris can take any random path in space.
- Space debris are tracked by radar and optical detectors.
- As per European Space Agency (ESA), as of January 2019, count of space debris is:
Large debris (> 10cm in size) = 34,000
Debris (1 – 10 cm size) = 9,00,000
Debris (<1cm size) = 128 million.
INTERNATIONAL SPACE STATION:
- It is a space station (habitable artificial satellite in low earth orbit).
- Its first component was launched in orbit in 1998 and more pieces were added in coming years.
- Astronauts from various nations have visited ISS since 2000 continuously.
- It consists of pressurised habitation modules, solar arrays, radiators, experimental bays, robotic arms, etc.
- It serves as a laboratory in space for conducting various experiments in biology, physics, astronomy, meteorology, etc in a zero-gravity environment.
- It maintains an orbit with an altitude between 330 and 435 km, in the centre of the Thermosphere layer of atmosphere. It circles the Earth in 92 minutes.
- It is a joint programme between 5 participating space agencies:
- NASA (United States): National Aeronautics and Space Administration
- Roscosmos (Russia)
- JAXA (Japan): Japan Aerospace Exploration Agency
- ESA (Europe): European Space Agency
- CSA (Canada): Canadian Space Agency
Space debris are a point of concern due their large momentum despite small size. The debris of Mission Shakti Anti-satellite mission was generated at an altitude much below the orbit of ISS. So, as the possibilities of them hitting ISS are seen quite low by Indian experts. But NASA is keeping a track on them for its own safety concerns.