Space Debries

 

                      Space Debries

                  

     Space Debris, also known as Space Junk or Space Pollution, is man-made debris found in space, outside the earth's atmosphere. These objects in orbit around the Earth have no use value and pose a threat to space travel. It can range from paint flakes or metal particles, to no longer needed satellite instrument lids, bolts or springs, to a complete discarded artificial moon or rocket stage . Space Debris or space junk is the residue of human activity in space, left in Earth's orbit since the beginning of space travel in the late 1950s. The very first man-made space debris thus comes from the protective casing of the Soviet satellite Sputnik and the coupling device of its launch vehicle. Space debris consists mainly of space engineering waste, spent rocket stages, old satellites, debris and fragments from crashes and explosions, but also dropped screws, nuts and paint chips .

                                   

        While there are about 2,000 active satellites orbiting Earth at the moment, there are also 3,000 dead ones littering space. What's more, there are around 34,000 pieces of space junk bigger than 10 centimetres in size and millions of smaller pieces that could nonetheless prove disastrous if they hit something else . More than 27,000 pieces of orbital debris, or “space junk,” are tracked by the Department of Defense’s global Space Surveillance Network (SSN) sensors. Much more debris -- too small to be tracked, but large enough to threaten human spaceflight and robotic missions -- exists in the near-Earth space environment.  Since both the debris and spacecraft are traveling at extremely high speeds (approximately 15,700 mph in low Earth orbit), an impact of even a tiny piece of orbital debris with a spacecraft could create big problems .

                               

         There are approximately 23,000 pieces of debris larger than a softball orbiting the Earth. They travel at speeds up to 17,500 mph, 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 more smaller micrometer-sized (0.000039 of an inch in diameter) debris .

                                     

            On July 24, 1996, in the first collision between an operational satellite and a piece of space debris, a fragment from the upper stage of a European Ariane rocket collided with Cerise, a French microsatellite. Cerise was damaged but continued to function. The first collision that destroyed an operational satellite happened on February 10, 2009, when Iridium 33, a communications satellite owned by the American company Motorola, collided with Cosmos 2251, an inactive Russian military communications satellite, about 760 km (470 miles) above northern Siberia, shattering both satellites . 

                            

    The worst space-debris event happened on January 11, 2007, when the Chinese military destroyed the Fengyun-1C weather satellite in a test of an anti-satellite system, creating more than 3,000 fragments, or more than 20 percent of all space debris. Within two years those fragments had spread out from Fengyun-1C’s original orbit to form a cloud of debris that completely encircled Earth and that would not reenter the atmosphere for decades. On January 22, 2013, the Russian laser-ranging satellite BLITS (Ball Lens in the Space) experienced a sudden change in its orbit and its spin, which caused scientists to abandon the mission. The culprit was believed to have been a collision with a piece of Fengyun-1C debris. Fragments from Fengyun-1C, Iridium 33, and Cosmos 2251 account for about one-half of all debris below 1,000 km (620 miles) .

                               

       As space debris orbits around the earth at tremendous speeds - about 15,700 miles per hour (25,265 kph) in low Earth orbit - it could cause significant damage to a satellite or a spacecraft in case of a collision .

                            

   2,000 active satellites in Earth's orbit

3,000 dead satellites in Earth's orbit

34,000 pieces of space junk larger than 10 centimetres

128 million pieces of space junk larger than 1 millimetre

One in 10,000: risk of collision that will require debris avoidance manoeuvres

25 debris avoidance manoeuvres by the ISS since 1999 .

        This is an idea proposed by NASA scientist Donald Kessler in 1978. He said that if there was too much space junk in orbit, it could result in a chain reaction where more and more objects collide and create new space junk in the process, to the point where Earth's orbit became unusable .

                     

     Japan's Aerospace Exploration Agency (JAXA) and the European Space Agency have partnered with start-ups to help with removal of space debris . While JAXA has launched a six-month demonstration project with Astroscale for the world's first debris removal mission, ESA is working with Swiss start-up ClearSpace for launching a mission in 2025.

                             

      Project NETRA is an initiative by the Indian Space Research Organisation (ISRO) which is an early warning system in space to detect debris and hazards to the Indian satellite . Under this project, the Indian space organisation plans to put up many observational facilities like telescopes, connected radars, data processing units, and a control center.

                         

 With best wishes from

                  

Suvendu Singha(India, Odisha, Balasore , Jaleswer)

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