Kosmos 1818

Kosmos 1818

Illustration of Kosmos 1818
Mission type	radar ocean reconnaissance satellite (RORSAT)
Satellite of	Earth
Launch date	February 1, 1987 23:31:00 UTC
Launch vehicle	Tsyklon-2
Launch site	Baikonur Cosmodrome
Mission duration	~ 5 to 6 months
COSPAR ID	1987-011A
Mass	1,500 kg (3,307 lb)
Power	TOPAZ nuclear reactor Plasma-2 SPT electric engine
Orbital elements
Eccentricity	0.001392
Inclination	65.0°
Apoapsis	790 km (491 mi)
Periapsis	810 km (503 mi)
Orbital period	100.6 min

Kosmos 1818 (Russian: Космос 1818) is a radar ocean reconnaissance satellite (RORSAT) that was launched by the Soviet Union February 1, 1987. It was put into a high orbit about 800 km (500 mi) from the Earth's surface. Its mission was monitoring the oceans for naval vessels. It had a mission life of about five or six months. It was powered by a nuclear reactor.^[1][2][3]

About July 4, 2008, either Kosmos 1818 was either struck by an object or a coolant tube cracked due to thermal stresses by repeated solar heating. This created at least thirty fragments.^[4][5]

Description

Kosmos 1818 was launched on February 1, 1987 on a Tsyklon-2 rocket from the Baikonur Cosmodrome. It was put into an orbit about 800 km (500 mi) above the Earth's surface at an inclination of 65° and a period of 100.6 minutes. Its NSSDC ID is 1987-011A, and its NORAD ID is 17369. The satellite had a mission life of about five to six months.^[1][2] The satellite was powered by TOPAZ 1 nuclear reactor. This was cooled by liquid sodium-potassium, NaK, metal, it uses a high-temperature moderator containing hydrogen and highly enriched fuel. It produces electricity using a thermionic converter. It had a Plazma-2 SPT electric engine.^[4] Its mission was to search the oceans for naval and merchant vessels. Unlike earlier Soviet RORSAT satellites, Kosmos 1818 and its twin, Kosmos 1867, were launched into high orbits. This avoided mishaps, such as occurred with Kosmos 954, which broke up over Canada in 1978, showering the Earth with radioactive debris.^[4] In 1992, Kosmos 1818 had an approximate visual magnitude of 3.3.^[6]

Fragmentation

About July 4, 2008, Comos 1818 was either hit by an object or a coolant tube cracked due to thermal stresses by repeated solar heating.^[5] The US Space Surveillance Network reported that about thirty objects were formed. These have orbital periods ranging from 100.5 to 101.5 minutes. Some of the debris appears to be metallic spheres. These could have resulted from the NaK coolant.

Russian Space Forces chief of staff General Alexander Yakushin indicated that the debris was high above the orbit of the International Space Station and did not pose any threat of radioactive contamination to the Earth.^[7]

References

1. ^ ^{a b} "Cosmos 1818". Real Time Satellite Tracking. N2YO.com. http://www.n2yo.com/satellite/?s=17369. Retrieved 24 January 2009. 
2. ^ ^{a b} "Cosmos 1818". NSSDC Master Catalog Search. NASA. http://nssdc.gsfc.nasa.gov/nmc/masterCatalog.do?sc=1987-011A. Retrieved 24 January 2009. 
3. ^ Broad, William J. (January 15, 1989), "Russians Disclose Satellites Carry New Reactor Type", New York Times, http://query.nytimes.com/gst/fullpage.html?res=950DE3DB153CF936A25752C0A96F948260&sec=&spon=&&scp=1&sq=cosmos%201818&st=cse 
4. ^ ^{a b c} "New Debris Seen from Decommissioned Satellite with Nuclear Power Source" (pdf). Orbital Debris Quarterly News. NASA. 24 January 2009. http://orbitaldebris.jsc.nasa.gov/newsletter/pdfs/ODQNv13i1.pdf. Retrieved 24 January 2009. 
5. ^ ^{a b} David, Leonard (15 January 2009). "Old Nuclear-Powered Soviet Satellite Acts Up". News. Space.com. http://www.space.com/news/090115-soviet-satellite-cosmos-1818.html. Retrieved 24 January 2009. 
6. ^ "Spacecraft Particularly Suited for International Participation: Category I". SPACEWARN Bulletin Number 461. NASA. March 25, 1992. http://nssdc.gsfc.nasa.gov/spacewarn/spx461-photosat.html. Retrieved 24 January 2009. 
7. ^ Isachenkov, Vladimir (21 January 2009), "Russia says old nuclear satellite poses no threat", MSNBC, http://www.msnbc.msn.com/id/28774132/