Space debris are defunct human-made objects in space—principally in Earth orbit—which no longer serve a useful function. 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. 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. Space debris represents a risk to spacecraft.
Kosmos is a designation given to many satellites operated by the Soviet Union and subsequently Russia. Kosmos 1, the first spacecraft to be given a Kosmos designation, was launched on 16 March 1962.
The Kessler syndrome, proposed by NASA scientist Donald J. Kessler in 1978, is a scenario in which the density of objects in low Earth orbit (LEO) due to space pollution is high enough that collisions between objects could cause a cascade in which each collision generates space debris that increases the likelihood of further collisions. In 2009 Kessler wrote that modeling results had concluded that the debris environment was already unstable, "such that any attempt to achieve a growth-free small debris environment by eliminating sources of past debris will likely fail because fragments from future collisions will be generated faster than atmospheric drag will remove them". One implication is that the distribution of debris in orbit could render space activities and the use of satellites in specific orbital ranges difficult for many generations.
The Satellite Catalog Number is a sequential nine-digit number assigned by the United States Space Command (USSPACECOM) in the order of launch or discovery to all artificial objects in the orbits of Earth and those that left Earth's orbit. The first catalogued object, catalog number 1, is the Sputnik 1 launch vehicle, with the Sputnik 1 satellite having been assigned catalog number 2. Objects that fail to orbit or orbit for a short time are not catalogued. The minimum object size in the catalog is 10 centimetres (3.9 in) in diameter. As of November 15, 2022, the catalog listed 54,200 objects, including 14,102 satellites that had been launched into orbit since 1957 of which 7,043 were still active. 24,146 of the objects were well tracked while 1,850 were lost. In addition USSPACECOM was also tracking 20,900 analyst objects. Analyst objects are variably tracked and in constant flux, so their catalog and element set data are not published. As of November 7, 2022 ESA estimated there were about 36,500 pieces of orbiting debris that are large enough for USSPACECOM to track.
Kosmos 1686, also known as TKS-4, was a heavily modified TKS spacecraft which docked unmanned to the Soviet space station Salyut 7 as part of tests to attach scientific expansion modules to stations in Earth orbit. The module which docked to the station was the FGB component of a TKS vehicle launched on September 27, 1985, and was designed to test systems planned for use on the Mir Core Module. The spacecraft docked with Salyut 7 on October 2, 1985, during the long-duration stay of the cosmonauts of its fifth principal expedition, which arrived on Soyuz T-14. It was the last flown TKS spacecraft.
Kosmos 1818 was a nuclear powered Soviet surveillance satellite in the RORSAT program, which monitored NATO vessels using radar. Kosmos 1818 was the first satellite to use the TOPAZ-1 fission reactor. In July 2008, the satellite was damaged, and leaked a trail of sodium coolant.
Kosmos 1867 is a nuclear powered radar ocean reconnaissance satellite (RORSAT) that was launched by the Soviet Union on July 10, 1987. It was put into an orbit of about 800 km (500 mi). Its mission was to monitor the oceans for naval and merchant vessels, and had a mission life of about eleven months.
Kosmos 6, also known as DS-P1 No.1 as part of the Dnepropetrovsk Sputnik programme and occasionally in the West as Sputnik 16 was a prototype radar target satellite for anti-ballistic missile tests, which was launched by the Soviet Union in 1962.
Kosmos 31, also known as DS-MT No.2 was a technology demonstration satellite which was launched by the Soviet Union in 1964 as part of the Dnepropetrovsk Sputnik programme. Its primary mission was to demonstrate an electric gyrodyne orientation system. It also carried a scientific research package as a secondary payload, which was used to study cosmic rays.
Kosmos 485, known before launch as DS-P1-Yu No.58, was a Soviet satellite which was launched in 1972 as part of the Dnepropetrovsk Sputnik programme. It was a 325-kilogram (717 lb) spacecraft, which was built by the Yuzhnoye Design Bureau, and was used as a radar calibration target for anti-ballistic missile tests.
Kosmos 215, also known as DS-U1-A No.1, was a Soviet satellite which was launched in 1968 as part of the Dnepropetrovsk Sputnik programme. It was a 385-kilogram (849 lb) spacecraft, which was built by the Yuzhnoye Design Bureau, and was used to study radiation and conduct optical observations of the atmosphere of the Earth. It was equipped with eight telescopes, including one for ultraviolet astronomy. It was primarily used to study the Sun, although several other X-ray emissions were detected.
In 2015, the maiden spaceflights of the Chinese Long March 6 and Long March 11 launch vehicles took place.
Kosmos 1456 was a Soviet US-K missile early warning satellite which was launched in 1983 as part of the Soviet military's Oko programme. The satellite was designed to identify missile launches using optical telescopes and infrared sensors.
Kosmos 1285 was a Soviet US-K missile early warning satellite which was launched in 1981 as part of the Soviet military's Oko programme. The satellite was designed to identify missile launches using optical telescopes and infrared sensors.
Kosmos 1261 was a Soviet US-K missile early warning satellite which was launched in 1981 as part of the Soviet military's Oko programme. The satellite was designed to identify missile launches using optical telescopes and infrared sensors.
Kosmos 2421 was a Russian spy satellite launched in 2006, but began fragmenting in early 2008. It also had the Konus-A science payload designed by Ioffe Institute to detect gamma-ray bursts. Three separate fragmentation events produced about 500 pieces of trackable debris. About half of those had already re-entered Earth's atmosphere by the fall of 2008.
Kosmos 1484, also known as Resurs-OE No.3-2 was a Soviet prototype Earth imaging satellite, launched in 1983 as part of the Resurs programme. It was a prototype of the Meteor-derived Resurs-O1 spacecraft, which paved the way for the first Resurs-O1 to fly in October 1985.
Kosmos-1408 was an electronic signals intelligence (ELINT) satellite operated by the Soviet Union. It was launched into low Earth orbit on 16 September 1982 at 14:55 UTC, replacing Kosmos-1378. It operated for around two years before becoming inactive and left in orbit.
