![](\"http:\/\/www.esa.int\/var\/esa\/storage\/images\/esa_multimedia\/images\/2017\/04\/don_kessler\/16908811-1-eng-GB\/Don_Kessler_small.jpg\")
<\/p>\n\t\t\t\t\t<\/p>\n
\nRetired astrophysicist and former NASA scientist Donald Kessler seen attending the European Conference on Space Debris at ESA in Darmstadt, Germany, on 18 April 2017.\n<\/p>\n
\nSince 1957, more than 5250 space launches have led to an orbiting population today of more than 23 000 tracked debris objects.\n<\/p>\n
\nOnly about 1200 are working satellites. The remaining are classified as space debris and no longer serve any useful purpose. A large percentage of the routinely tracked objects are fragments from the approximately 290 breakups, explosions and collisions of satellites or rocket bodies that are known to have occurred.\n<\/p>\n
\nAn estimated 750 000 objects larger than 1 cm and a staggering 166 million pieces larger than 1 mm are thought to reside in commercially and scientifically valuable Earth orbits.\n<\/p>\n
\nRelative orbital speeds of up 56 000 km\/h mean that even centimetre-sized debris can seriously damage or disable a working satellite, and collisions with objects larger than 10 cm will lead to catastrophic break-ups, releasing clouds of hazardous debris fragments that will go on to cause further catastrophic collisions, potentially leading to an unstable debris environment in some orbital regions.\n<\/p>\n
\nThis run-away scenario is known as the \u201cKessler syndrome<\/a>\u201d because it was first postulated by Don in 1978.\n<\/p>\n \nMore information<\/b>\n<\/p>\n \nhttp:\/\/www.esa.int\/debris<\/a><\/p>\n","protected":false},"excerpt":{"rendered":" \nRetired astrophysicist and former NASA scientist Donald Kessler seen attending the European Conference on Space Debris at ESA in Darmstadt, Germany, on 18 April 2017.\n<\/p>\n \nSince 1957, more than 5250 space launches have led to an orbiting population today of more than 23 000 tracked debris objects.\n<\/p>\n \nOnly about 1200 are working satellites. The remaining are classified as space debris and no longer serve any useful purpose. A large percentage of the routinely tracked objects are fragments from the approximately 290 breakups, explosions and collisions of satellites or rocket bodies that are known to have occurred.\n<\/p>\n \nAn estimated 750 000 objects larger than 1 cm and a staggering 166 million pieces larger than 1 mm are thought to reside in commercially and scientifically valuable Earth orbits.\n<\/p>\n \nRelative orbital speeds of up 56 000 km\/h mean that even centimetre-sized debris can seriously damage or disable a working satellite, and collisions with objects larger than 10 cm will lead to catastrophic break-ups, releasing clouds of hazardous debris fragments that will go on to cause further catastrophic collisions, potentially leading to an unstable debris environment in some orbital regions.\n<\/p>\n \nThis run-away scenario is known as the “Kessler syndrome<\/a>” because it was first postulated by Don in 1978.\n<\/p>\n \nMore information<\/b>\n<\/p>\n<\/p>\n