Kosmos 1867 (russian: Космос 1867) is a nuclear powered radar ocean reconnaissance satellite (RORSAT) that was launched by the

Soviet Union The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen national ...

on July 10, 1987. It was put into an orbit of about . Its mission was to monitor the oceans for naval and merchant vessels, and had a mission life of about eleven months.

Description

Kosmos 1867 was launched on July 10, 1987, on a Tsyklon-2 rocket from the

Baikonur Cosmodrome The Baikonur Cosmodrome ( kk, Байқоңыр ғарыш айлағы, translit=Baiqoñyr ğaryş ailağy, ; russian: Космодром Байконур, translit=Kosmodrom Baykonur, ) is a spaceport in an area of southern Kazakhstan leased to R ...

. It was put into an orbit about above the Earth's surface at an inclination of 65° and a period of 100.8 minutes. The satellite had a mission life of about 11 months. The satellite was powered by TOPAZ 1 nuclear reactor. This reactor was cooled by liquid sodium-potassium (

NaK In data networking, telecommunications, and computer buses, an acknowledgment (ACK) is a signal that is passed between communicating processes, computers, or devices to signify acknowledgment, or receipt of message, as part of a communicatio ...

) metal, and used a high-temperature moderator containing hydrogen and highly enriched fuel. The reactor produced electricity using a thermionic converter. The satellite used a ''Plazma-2 SPT''

Hall-effect thruster In spacecraft propulsion, a Hall-effect thruster (HET) is a type of ion thruster in which the propellant is accelerated by an electric field. Hall-effect thrusters (based on the discovery by Edwin Hall) are sometimes referred to as Hall thruster ...

for propulsion. The mission of Kosmos 1867 was to search the oceans for naval and merchant vessels. Unlike earlier Soviet RORSAT satellites, Kosmos 1867 and its twin,

Kosmos 1818 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 ...

, were launched into high orbits. This reduced the likelihood of mishaps resulting in uncontrolled re-entry of radioactive material, as had occurred with

Kosmos 954 Kosmos 954 (russian: Космос 954) was a reconnaissance satellite launched by the Soviet Union in 1977. A malfunction prevented safe separation of its onboard nuclear reactor; when the satellite reentered the Earth's atmosphere the follow ...

and

Kosmos 1402 Kosmos 1402 (russian: Космос 1402) was a Soviet spy satellite that malfunctioned, resulting in the uncontrolled re-entry of its nuclear reactor and its radioactive uranium fuel. Kosmos 1402 was launched on August 30, 1982, and re-entered the ...

, which showered the Earth with

radioactive Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is consid ...

debris. In 1992, Kosmos 1867 had a visual magnitude of approximately 3.3. Kosmos 1867 had become damaged, resulting in several fragments of

space debris Space debris (also known as space junk, space pollution, space waste, space trash, or space garbage) are defunct human-made objects in space—principally in Earth orbit—which no longer serve a useful function. These include derelict spacecr ...

. It is suspected that the coolant tube had leaked NaK metal, in a manner similar to

in 2008. On April 8, 2014, the US Space Surveillance Network reported that 11 new objects were detected, and 24 more objects ware reported on April 15, 2014. The coolant tube of Kosmos 1867 may have cracked due to thermal stresses by repeated solar heating, or by an impact.

References

{{Orbital launches in 1987 Reconnaissance satellites of the Soviet Union Kosmos satellites Nuclear power in space 1987 in the Soviet Union Spacecraft launched in 1987