Program: Iridium

As the program was originaly thought with 77 satellites, it was named after the 77th element in the periodical table: Iridium

The Iridium system is owned by Iridium LLC, an international consortium of 17 investor organizations representing telecommunications and industrial companies worldwide, with Motorola Satellite Communications Group serving as the prime contractor. The investors are: Iridium Africa Corporation, Iridium Canada, Inc., Iridium China (Hong Kong), Ltd., Iridium India Telecom Limited, Iridium Middle East Corporation, Iridium SudAmerica Corporation, Khrunichev State Research and Production Space Center of the Russian Federation, Korea Mobile Telecommunications of Korea, Lockheed Martin Corporation and Motorola, Inc. of the U.S., Nippon Iridium Corporation of Japan, o.tel.o communications GmbH of Germany, Pacific Electric Wire & Cable Co., Ltd. of Taiwan, Raytheon Company of the U.S., Sprint Corporation of the U.S., STET Group - Societa Finanziara Telefonica per Azioni of Italy, and Thai Satellite Telecommunications Co., Ltd. of Thailand.

The cost of the global system is close to $7 billion. The commercial launch date is 23 Sep 1998 Cost per satellite: $62 million

On 15 Aug 1999 the company filled for bankrupcy. In Feb 2000 Craig McCaw's Eagle River Investments provided $74.6 million. On 6 Mar 2000 McCaw's firm finaly said it was not interested in Iridium anymore; the firm wants to focus on data communication systems. Insurance paid $240 million for failed Iridium satellites.

The network officially closed on 17 Mar 2000 after selling 55,000 terminals (approx $3000 each). The limited service still available stopped on 24 Aug 2000.

But on 20 Nov 2000 the assets of Iridium LLC and its subsidiaries were sold to Iridium Satellite LLC for $25 million ($6.5 million in cash and $18.5 million in convertible debt). A few days later it was known that the DoD purchased 2 years of satellite telephony services from the new owner and would receive more than 15000 handsets and unlimited time usage (20000 government users). Contract worth $72 million. The contract has options that bring the total value to $252 million with service till Dec 2007. The system will be upgraded for classified services.

In Apr 2001, investors from Brazil, Australia and Saudi Arabia are said to own 61 percent of Iridium LLC, which causes a problem as foreign ownership should be limited to 25% to get a licence.

Dialup internet access is possible at 2.4 kbps and direct-internet data access tops at 10 kbps. FCC granted a new licence in July 2001 for a 3.5 MHz segment in both 1.990-2.025 and 2.165-2.200 GHz bands.

In Dec 2001, the company states that they do not intend to launch new satellites before 2010 and build new satellites before 2020! 14 spare satellites are waiting on the ground.

In Jul 2005, 66 satellites are operational and 11 are in orbital storage.

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Iridium Next

Iridium Next (S2110) replaced the first constellation from 2017 on. It offers higher bandwidth for data transmissions. Lockheed Martin and Thales Alenia Space were the 2 final bidders and Thales Alenia Space was finally selected. Coface, the French credit agency, commited to cover 95% of the $1.8 billion credit facility. 72 satellites are to be launched and 9 ground spare built. The program is worth $2.9 billion (including launches and ground facilities). Orbital is in charge of payload and bus integration.
Satellites also host a secondary payload: the exactView payload for AIS monitoring for ExactEarth (procured from Harris Corporation).

In 2019 the US DoD awarded a 7-year, $739 million contract for unlimited use of the constellation for the existing 125000 military subscribers.

Iridium Certus is a broadband service to provide upto 1.4 Mbps speeds.

The GMDSS (Global Maritime Distress and Safety System) service for the International Maritime Organisation was officially launched in late-2020, taking over from Inmarsat.

Iridium Next Specifications
Iridium Next Payload

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External resources

http://www.iridium.com/

http://www2.satellite.eu.org/sat/vsohp/iridium.html
http://www.aireon.com/Home
http://www.rod.sladen.org.uk/iridium.htm

Technical data

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Slots and planes of first constellation

slot	satellites #
plane 1 (158)	62, 63, 64, 65, 66, 67, 68, 70, 72, 73, 74, 75
plane 2 (189)	11, 20, 22, 23, 24, 25, 26, 45, 46, 47, 48, 49, 69, 76, 71
plane 3 (221)	27, 28, 29, 30, 31, 32, 33, 55, 57, 58, 59, 60
plane 4 (252)	4, 5, 6, 7, 8, 19, 34, 35, 36, 37, 51, 61
plane 5 (284)	9, 10, 11, 12, 13, 14, 16, 50, 52, 53, 54, 56, 83, 84, 85, 86
plane 6 (316)	15, 17, 18, 20, 21, 38, 39, 40, 41, 42, 43, 44, 77, 79, 80, 81, 82

In early 1999 12 satellites were reported as failed

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First constellation overview

Orbit type	LEO
Orbit range	780 km, circular
Nb of satellites	66 + 7 backup
Nb of planes	6
Inclination	86.4°
Nb beams per satellite	48
Coverage	4700 km²
Modulation	FNMA/TDMA
Mobile frequencies	Uplink: L-band Downlink: 1610-1626.5 MHz
Satellite mass	725 kg
Coverage	all longitudes, 80N - 80S latitudes
Operational date	23 Sep 1998

TT&C: uplink: 29.1-29.3 GHz, downlink: 19.4-19.6 GHz

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Slots and planes of second constellation

plane 1 (158)	145	143	140	148	150		144	149	146	142	157
plane 2 (189)	134	141	137	116	135	151	120	113	138	130	131
plane 3 (221)	117			123	126			121	118
plane 4 (252)	119	122	128	107	132	129	127	133	125	136	139
plane 5 (284)								105	108
plane 6 (316)	102	112	104	114	103	109	106	152	147	110	111

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