Are we close to it? What can be done about it? The term comes from the name of a retired NASA scientist, Donald J. Kessler, known for a paper he wrote in the 1970s, "Collision Frequency of Artificial Satellites: The Creation of a Debris Belt." It hypothesized that the amount of artificial debris in low earth orbit would in time reach a tipping point, creating a cascade effect where collisions cause smaller debris to float around, causing further collisions, ending with a sort of hollow and impassable sphere around the earth rendering further space usage and exploration impossible for generations. NASA was impressed by his exposition of this threat, and Kessler had written himself into a promotion: he became the head of the Orbital Debris Program Office. The term "Kessler syndrome" for this effect was first employed a short time later by a NORAD employee. John Gabbard. The work of Kessler and Gabbard was popularized in 1982 by Jim Shefter, ...