The trackers (NORAD) who fed the database were aware of other objects in orbit, many of which were the result of in-orbit explosions. Gabbard diagram of almost 300 pieces of debris from the disintegration of the five-month-old third stage of the Chinese Long March 4 booster on 11 March 2000 NASA later published modified versions of the database in two-line element set, and beginning in the early 1980s the CelesTrak bulletin board system re-published them. After the launch of Sputnik, the North American Aerospace Defense Command (NORAD) began compiling a database (the Space Object Catalog) of all known rocket launches and objects reaching orbit: satellites, protective shields and upper-stages of launch vehicles. But even before that, beside natural ejecta from Earth, humans might have produced ejecta that became space debris, as in the August 1957 Pascal B test. Space debris began to accumulate in Earth orbit immediately with the first launch of an artificial satellite Sputnik 1 into orbit in October 1957. 6.5.2 Insufficient participation of private actors.6.4 National and international regulation.1.1.1 Debris history in particular years.The ISS has Whipple shielding to resist damage from small MMOD however, known debris with a collision chance over 1/10,000 are avoided by maneuvering the station. įor comparison, the International Space Station orbits in the 300–400 kilometres (190–250 mi) range, while the two most recent large debris events-the 2007 Chinese antisat weapon test and the 2009 satellite collision-occurred at 800 to 900 kilometres (500 to 560 mi) altitude. īelow 2,000 km (1,200 mi) Earth- altitude, pieces of debris are denser than meteoroids most are dust from solid rocket motors, surface erosion debris like paint flakes, and frozen coolant from RORSAT (nuclear-powered satellites). Collisions with debris have become a hazard to spacecraft the smallest objects cause damage akin to sandblasting, especially to solar panels and optics like telescopes or star trackers that cannot easily be protected by a ballistic shield. When the smallest objects of artificial space debris (paint flecks, solid rocket exhaust particles, etc.) are grouped with micrometeoroids, they are together sometimes referred to by space agencies as MMOD (Micrometeoroid and Orbital Debris). As of January 2019, more than 128 million pieces of debris smaller than 1 cm (0.4 in), about 900,000 pieces of debris 1–10 cm, and around 34,000 of pieces larger than 10 cm (3.9 in) were estimated to be in orbit around the Earth. However, these are just the objects large enough to be tracked.
Īs of January 2021, the US Space Surveillance Network reported 21,901 artificial objects in orbit above the Earth, including 4,450 operational satellites. The measurement, mitigation, and potential removal of debris are conducted by some participants in the space industry. Several spacecraft, both crewed and uncrewed, have been damaged or destroyed by space debris. Space debris is typically a negative externality-it creates an external cost on others from the initial action to launch or use a spacecraft in near-Earth orbit-a cost that is typically not taken into account nor fully accounted for in the cost by the launcher or payload owner. Space debris represents a risk to spacecraft. In addition to derelict human-made objects left in orbit, other examples of space debris include fragments from their disintegration, erosion and collisions or even paint flecks, solidified liquids expelled from spacecraft, and unburned particles from solid rocket motors.
These include derelict spacecraft-nonfunctional spacecraft and abandoned launch vehicle stages-mission-related debris, and particularly numerous in Earth orbit, fragmentation debris from the breakup of derelict rocket bodies and spacecraft. Space debris (also known as space junk, space pollution, space waste, space trash, or space garbage) is defunct human-made objects in space-principally in Earth orbit-which no longer serve a useful function.