India has put in place appropriate measures to manage the increasing space debris in Low Earth Orbit comprising defunct satellites, discarded rocket stages and other orbital trash, Union minister Jitendra Singh told the Lok Sabha.

Indian Space Research Organisation (ISRO) has been an active member of the Inter-Agency Space Debris Coordination Committee (IADC) and has contributed immensely to the IADC and UN guidelines for safe and sustainable space operations.

Mechanisms are in place for ensuring that the space activities are conducted in a safe and sustainable manner. 

The mechanisms include:

i) Establishment of facilities for tracking and monitoring of space objects.

ii) Best practices such as passivation of launch vehicle upper stages, conjunction assessment and collision avoidance for satellites, post mission disposal of satellites and upper stages.

iii) Operationalisation of ISRO System for Safe and Sustainable Space Operations Management (IS4OM) for safeguarding Indian space assets against space environmental hazards, to pursue the related R&D activities, and also to contribute to awareness raising on the long-term sustainability of outer space activities.

What is space debris?

• Ever since the start of the space age there has been more space debris in orbit than operational satellites.

• The amount of objects, combined mass and combined area has been steadily rising since the beginning of the space age, leading to the appearance of involuntary collisions between operational payloads and space debris. 

• Space debris encompasses both natural meteoroid and artificial (human-made) orbital debris. Meteoroids are in orbit about the Sun, while most artificial debris is in orbit about the Earth (hence the term “orbital” debris).

• Orbital debris is any human-made object in orbit about the Earth that no longer serves a useful function. Such debris includes non-functional spacecraft, abandoned launch vehicle stages, mission-related debris, and fragmentation debris.

• There are approximately 23,000 pieces of debris larger than a softball orbiting the Earth. They travel at speeds up to 28,000 kmph, fast enough for a relatively small piece of orbital debris to damage a satellite or a spacecraft. 

• There are half a million pieces of debris the size of a marble or larger (up to 0.4 inches, or 1 centimeter) or larger, and approximately 100 million pieces of debris about .04 inches (or one millimeter) and larger. There is even smaller micrometer-sized (0.000039 of an inch in diameter) debris.

• Even tiny paint flecks can damage a spacecraft when traveling at these velocities. A number of space shuttle windows were replaced because of damage caused by material that was analysed and shown to be paint flecks. In fact, millimeter-sized orbital debris represents the highest mission-ending risk to most robotic spacecraft operating in low Earth orbit.

• The International Space Station (ISS) orbits Earth at an altitude of just over 400 km. In the two decades since its launch, about 30 ‘collision avoidance manoeuvres’ have been performed in order to dodge space debris, with three taking place in 2020 alone. If a potential collision appears imminent, and there is no time to move the Station, they can take emergency shelter.

• In 1996, a French satellite was hit and damaged by debris from a French rocket that had exploded a decade earlier.

• In February, 2009, a defunct Russian spacecraft collided with and destroyed a functioning US Iridium commercial spacecraft. The collision added more than 2,300 pieces of large, trackable debris and many more smaller debris to the inventory of space junk.

• China’s 2007 anti-satellite test, which used a missile to destroy an old weather satellite, added more than 3,500 pieces of large, trackable debris and many more smaller debris to the debris problem.

• Not only a hazard, space debris increases the cost for satellite operators. Satellite operators in the geostationary orbit have estimated protective and mitigation measures account for about 5-10 per cent of mission costs and for lower-Earth orbits the cost is higher.

• The most important action currently is to prevent the unnecessary creation of additional orbital debris. This can be done through prudent vehicle design and operations. Cleaning up the environment remains a technical and economic challenge.

• As space debris poses a problem for the near Earth environment on a global scale, only a globally supported solution can be the answer.

• The United Nations Committee on the Peaceful Uses of Outer Space by the United Nations Office for Outer Space Affairs (UNOOSA) has paid particular attention to the issue of preventing and minimising the creation of space debris.

How long will orbital debris remain in Earth orbit?

• The higher the altitude, the longer the orbital debris will typically remain in Earth orbit. Debris left in orbits below 600 km normally fall back to Earth within several years. At an altitude of 800 km, the time for orbital decay is often measured in decades. Above 1,000 km, orbital debris will normally continue circling the Earth for a century or more.

• A significant amount of debris does not survive the severe heating that occurs during re-entry. Components which do survive are most likely to fall into the oceans or other bodies of water.

Inter-Agency Space Debris Coordination Committee (IADC)

The Inter-Agency Space Debris Coordination Committee (IADC) is an international governmental forum for the worldwide coordination of activities related to the issues of human-made and natural debris in space.

The primary purposes of the IADC are:

i) To exchange information on space debris research activities between member space agencies.

ii) To facilitate opportunities for cooperation in space debris research.

iii) To review the progress of ongoing cooperative activities.

iv) To identify debris mitigation options.

The IADC member agencies include:

• ASI (Agenzia Spaziale Italiana)

• CNES (Centre National d'Etudes Spatiales)

• CNSA (China National Space Administration)

• CSA (Canadian Space Agency)

• DLR (German Aerospace Center)

• ESA (European Space Agency)

• ISRO (Indian Space Research Organisation)

• JAXA (Japan Aerospace Exploration Agency)

• KARI (Korea Aerospace Research Institute)

• NASA (National Aeronautics and Space Administration)

• ROSCOSMOS (State Space Corporation)

• SSAU (State Space Agency of Ukraine)

• UK Space Agency.

A Steering Group and four specified Working Groups covering measurements (WG1), environment and database (WG2), protection (WG3) and mitigation (WG4) make up the IADC.

It provides information to the public about the IADC, its member agencies, and past and current debris-related activities.

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