Iridium 33 was a

communications satellite A communications satellite is an artificial satellite that relays and amplifies radio telecommunication signals via a transponder; it creates a communication channel between a source transmitter and a receiver at different locations on Earth ...

launched by

Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-ei ...

for

Iridium Communications Iridium Communications Inc. (formerly Iridium Satellite LLC) is a publicly traded American company headquartered in McLean, Virginia. Iridium operates the Iridium satellite constellation, a system of 66 active satellites and 9 in-orbit spares us ...

. It was launched into

low Earth orbit A low Earth orbit (LEO) is an orbit around Earth with a period of 128 minutes or less (making at least 11.25 orbits per day) and an eccentricity less than 0.25. Most of the artificial objects in outer space are in LEO, with an altitude never m ...

from Site 81/23 at the

Baikonur Cosmodrome ''Baiqoñyr ğaryş ailağy'' rus, Космодром Байконур''Kosmodrom Baykonur'' , image = Baikonur Cosmodrome Soyuz launch pad.jpg , caption = The Baikonur Cosmodrome's "Gagarin's Start" Soyuz ...

at 01:36 UTC on 14 September 1997, by a

Proton-K The Proton-K, also designated Proton 8K82K after its GRAU index or SL-12 after its model number, 8K82K, was a Russian, previously Soviet, carrier rocket derived from the earlier Proton. It was built by Khrunichev, and launched from sites 81 an ...

rocket with a Block DM2 upper stage. The launch was arranged by

International Launch Services International Launch Services, Inc. (ILS) is a joint venture with exclusive rights to the worldwide sale of commercial Angara and Proton rocket launch services. Proton launches take place at the Baikonur Cosmodrome in Kazakhstan while Angara is l ...

(ILS). It was operated in Plane 3 of the

Iridium satellite constellation The Iridium satellite constellation provides L band voice and data information coverage to satellite phones, pagers and integrated transceivers over the entire surface of Earth. Iridium Communications owns and operates the constellation, addit ...

, with an

ascending node An orbital node is either of the two points where an orbit intersects a plane of reference to which it is inclined. A non-inclined orbit, which is contained in the reference plane, has no nodes. Planes of reference Common planes of refere ...

of 230.9°.

Mission

Iridium 33 was part of a commercial communications network consisting of a constellation of 66 LEO spacecraft. The system uses

L-Band The L band is the Institute of Electrical and Electronics Engineers (IEEE) designation for the range of frequencies in the radio spectrum from 1 to 2 gigahertz (GHz). This is at the top end of the ultra high frequency (UHF) band, at the lowe ...

to provide global communications services through portable handsets. Commercial service began in 1998. The system employs ground stations with a master control complex in Landsdowne,

Virginia Virginia, officially the Commonwealth of Virginia, is a state in the Mid-Atlantic and Southeastern regions of the United States, between the Atlantic Coast and the Appalachian Mountains. The geography and climate of the Commonwealth are ...

, a backup in

Italy Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical ...

, and a third engineering center in Chandler,

Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...

Spacecraft

The spacecraft was 3-axis stabilized, with a

hydrazine Hydrazine is an inorganic compound with the chemical formula . It is a simple pnictogen hydride, and is a colourless flammable liquid with an ammonia-like odour. Hydrazine is highly toxic unless handled in solution as, for example, hydrazine ...

propulsion system. It had 2

solar panels A solar cell panel, solar electric panel, photo-voltaic (PV) module, PV panel or solar panel is an assembly of photovoltaic solar cells mounted in a (usually rectangular) frame, and a neatly organised collection of PV panels is called a photo ...

with 1-axis articulation. The system employed L-Band using

FDMA Frequency-division multiple access (FDMA) is a channel access method used in some multiple-access protocols. FDMA allows multiple users to send data through a single communication channel, such as a coaxial cable or microwave beam, by dividing ...

/ TDMA to provide voice at 4.8 kbps and data at 2400 bps with a 16 dB margin. Each satellite had 48 spot beams for Earth coverage and used Ka-Band for crosslinks and ground commanding.

Destruction

On 10 February 2009, at 16:56 UTC, at about 800 km altitude,

Kosmos 2251 Kosmos-2251 (russian: Космос-2251 meaning ''Cosmos 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 Kos ...

(1993-036A) (a derelict Strela satellite) and Iridium 33 collided, resulting in the destruction of both spacecraft.

NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeedin ...

reported that a large amount 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 spacec ...

was produced by the collision, i.e. 1347 debris for Kosmos 2251 and 528 for Iridium 33.

References

{{authority control Communications satellites in low Earth orbit 2009 in spaceflight Satellite collisions Satellites formerly orbiting Earth Spacecraft launched in 1997 Iridium satellites

Mission

Spacecraft

Destruction

See also

References