help deal with fragments from in size is the laser broom, a proposed multimegawatt land-based laser that could deorbit debris: the side of the debris hit by the laser would ablate and create a thrust that would change the eccentricity of the remains of the fragment until it would re-enter and be destroyed harmlessly. Potential triggers The Envisat satellite is a large, inactive satellite with a mass of that orbits at , an altitude where the debris environment is the greatest—two catalogued objects can be expected to pass within about of Envisat every year—and likely to increase. Don Kessler predicted in 2012 that it could easily become a major debris contributor from a collision during the next 150 years that it will remain in orbit. SpaceX's Starlink program raises concern among many experts about significantly worsening the possibility of Kessler Syndrome due to the large number of satellites the program aims to place in LEO, as the program's goal will more than double the satellites currently in LEO. In response to these concerns, SpaceX said that a large part of Starlink satellites are launched at a lower altitude of to achieve lower latency (versus as originally planned), and failed satellites or debris are thus expected to deorbit within five years even without propulsion, due to atmospheric drag. In fiction The 2013 film Gravity features a Kessler syndrome catastrophe as the inciting incident of the story, when Russia shoots down an old satellite. Neal Stephenson's 2015 novel Seveneves begins with the unexplained explosion of the Moon into seven large pieces, the subsequent creation of a cloud of debris by Kessler syndrome collisions, and the eventual bombardment of Earth's surface by lunar meteoroids. See also 1961 and 1963 1985 ASM-135 ASAT test – 1985 United States anti-satellite missile test anti-satellite missile test Citations Bibliography . . . . . . . . Further reading An article in the July 2009 issue of Popular Mechanics by Glenn Harlan Reynolds discusses the Kessler syndrome in regards to the February 2009 satellite collision and how international law may need to address the problem to help prevent future incidents: Reynolds, G. H. (2009, July). "Collision course". Popular Mechanics, pp. 50–52. Documentary: Collision point: The Race to Clean Up Space (length: 22 minutes 28 seconds), included in the extra material on the Blu-ray Disc for the film Gravity. External links Donald Kessler's Web Page at uwo.ca Orbiting