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.
Strela is a Russian military communications satellite constellation operating in low Earth orbit. These satellites operate as mailboxes ("store-and-forward"): they remember the received messages and then resend them after the scheduled time, or by a command from the Earth. Some sources state the satellites are capable of only three months of active operation, but through coordination with others they can serve for about five years. The satellites are used for transmission of encrypted messages and images.
Orbcomm is a family of low Earth orbit communications satellites, operated by the United States satellite communications company Orbcomm. As of July 2014, 51 such satellites have orbited Earth, with 50 still continuing to do so.
Kosmos-2251, was a Russian Strela-2M military communications satellite. It was launched into Low Earth orbit from Site 132/1 at the Plesetsk Cosmodrome at 04:17 UTC on 16 June 1993, by a Kosmos-3M carrier rocket.· The Strela satellites had a lifespan of 5 years, and the Russian government reported that Kosmos-2251 ceased functioning in 1995. Russia was later criticised by The Space Review for leaving a defunct satellite in a congested orbit, rather than deorbiting it. In response, Russia noted that they were not required to do so under international law. In any case, the KAUR-1 satellites had no propulsion system, which is usually required for deorbiting.
Strictly speaking, a satellite collision is when two satellites collide while in orbit around a third, much larger body, such as a planet or moon. This definition can be loosely extended to include collisions between sub-orbital or escape-velocity objects with an object in orbit. Prime examples are the anti-satellite weapon tests.
The Iridium satellite constellation provides L band voice and data information coverage to satellite phones, satellite messenger communication devices and integrated transceivers, as well as two-way satellite messaging service to supported Android smartphones, over the entire surface of Earth. Iridium Communications owns and operates the constellation, additionally selling equipment and access to its services. It was conceived by Bary Bertiger, Raymond J. Leopold and Ken Peterson in late 1987 and then developed by Motorola on a fixed-price contract from July 29, 1993, to November 1, 1998, when the system became operational and commercially available.
On February 10, 2009, two communications satellites—the active commercial Iridium 33 and the derelict Russian military Kosmos 2251—accidentally collided at a speed of 11.7 km/s (26,000 mph) and an altitude of 789 kilometres (490 mi) above the Taymyr Peninsula in Siberia. It was the first time a hypervelocity collision occurred between two satellites; previous incidents had involved a satellite and a piece of space debris.
The LM-700 is a satellite bus which was built by Lockheed Martin between the mid-1990s and early 2000s. Typically used for low Earth orbit communications satellites, ninety nine were built, all but one for Iridium Satellite LLC. The exception was a technology development satellite for the United States Air Force, which was never launched. In addition, two boilerplate satellites were launched on a test flight of the Chinese Long March 2C rocket.
Kosmos 53, also known as DS-A1 No.5 was a technology demonstration satellite which was launched by the Soviet Union in 1965 as part of the Dnepropetrovsk Sputnik programme. Its primary mission was to demonstrate technologies for future Soviet military satellites. It also conducted radiation experiments.
Kosmos 70, also known as DS-A1 No.7 was a technology demonstration satellite which was launched by the Soviet Union in 1965 as part of the Dnepropetrovsk Sputnik programme. Its primary mission was to demonstrate technologies for future Soviet military satellites. It also conducted radiation experiments.
Kosmos 49, also known as DS-MG No.2 was a scientific satellite which was launched by the Soviet Union in 1964. This mission used proton magnetometers to map the Earth's magnetic field and, along with Kosmos 26, represented the USSR's contribution to the International Quiet Solar Year World Magnetic Survey. The corresponding American measurements were performed by the satellites OGO 2 and OGO 4. It also conducted scientific research into the Earth's infrared flux and ultraviolet flux.
Kosmos 51, also known as DS-MT No.3 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 and the luminosity of the stellar background.
Kosmos 14, also known as Omega No.1, was a satellite which was launched by the Soviet Union in 1963. It was an Omega satellite, derived from the Dnepropetrovsk Sputnik series.
Kosmos 23, also known as Omega No.2, was a satellite which was launched by the Soviet Union in 1963. It was an Omega satellite, derived from the Dnepropetrovsk Sputnik series. It was a 347 kilograms (765 lb) spacecraft, which was built by the Yuzhnoye Design Office, and was used to conduct experiments with the use of gyroscopes to control spacecraft, for VNIIEM.
USA-117, also known as GPS IIA-16, GPS II-25 and GPS SVN-33, is an American navigation satellite which forms part of the Global Positioning System. It was the sixteenth of nineteen Block IIA GPS satellites to be launched.
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 2394 is one of a set of three Russian military satellites launched in 2002 as part of the GLONASS satellite navigation system. It was launched with Kosmos 2395 and Kosmos 2396.
