GLONASS Space Segment - Revision history

Vicente.Navarro at 14:01, 15 August 2024

2024-08-15T14:01:16Z

← Older revision		Revision as of 14:01, 15 August 2024
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	==GLONASS Satellite Constellation==		==GLONASS Satellite Constellation==
	[[File:GlonassConstellation.JPG\|Glonass Constellation\|400px\|thumb\|right]]		[[File:GlonassConstellation.JPG\|Glonass Constellation\|400px\|thumb\|right]]
	The [[GLONASS General Introduction\|GLONASS]] space segment consists nominally of 24 operational satellites, distributed over three orbital planes.~~<ref> [http://www.sdcm.ru/index_eng.html Russian system of differentional correction and monitoring]</ref>~~		The [[GLONASS General Introduction\|GLONASS]] space segment consists nominally of 24 operational satellites, distributed over three orbital planes.
	The longitude of ascending node differs by 120 deg from plane to plane. There are eight satellites per plane, separated 45 deg in argument of latitude. The difference in the argument of latitude of satellites in equivalent slots in two different orbital planes is 15 deg. Each satellite is identified by its slot number, which defines the orbital plane and its location within the plane.<ref>[~~http~~://~~new.~~glonass-iac.ru/en/~~CUSGLONASS~~/~~index.php~~ GLONASS ~~SCC~~ Information]</ref>		The longitude of ascending node differs by 120 deg from plane to plane. There are eight satellites per plane, separated 45 deg in argument of latitude. The difference in the argument of latitude of satellites in equivalent slots in two different orbital planes is 15 deg. Each satellite is identified by its slot number, which defines the orbital plane and its location within the plane.<ref>[https://glonass-iac.ru/en/cus/ GLONASS Constellation Status Information]</ref>

	The [[GPS General Introduction\|GPS]] space segment also consists of nominally 24 satellites, which are, however, distributed over six orbital planes, differing from plane to plane by 60 deg in longitude of the ascending node.		The [[GPS General Introduction\|GPS]] space segment also consists of nominally 24 satellites, which are, however, distributed over six orbital planes, differing from plane to plane by 60 deg in longitude of the ascending node.

Claudia.Prajanu at 12:55, 22 June 2018

2018-06-22T12:55:28Z

← Older revision		Revision as of 12:55, 22 June 2018
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	Satellites carry atomic clocks and the payload needed for handling (receiving, processing and transmitting) navigation data. They also have reflectors to allow laser ranging from dedicated ground stations.		Satellites carry atomic clocks and the payload needed for handling (receiving, processing and transmitting) navigation data. They also have reflectors to allow laser ranging from dedicated ground stations.

	Differences between GPS and GLONASS constellations are summarized in the following table:~~<ref name="GLONASS.it">[http://www.glonass.it/eng/glonass-story.aspx/ GLONASS System Description in glonass.it web site]</ref>~~		Differences between GPS and GLONASS constellations are summarized in the following table:

	{\| class="wikitable"		{\| class="wikitable"
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	*'''First generation'''. The first true GLONASS satellites were launched between 1985 and 1990. They are divided into different block vehicles (Block IIa, IIb, and IIv), being the design lifetimes the main difference between blocks. The lifetimes ranged from the 2-year design of Block IIb to 3-year of Block IIv, with many spacecraft exceeding this (up to 4.5 years).These satellites are all 3-Axis stabilized spacecrafts with satellite mass of about 1 250 Kg, being equipped with a basic propulsion system to allow relocation within the constellation. They have improved time and frequency standards over the previous spacecraft prototypes, with increased frequency stability.		*'''First generation'''. The first true GLONASS satellites were launched between 1985 and 1990. They are divided into different block vehicles (Block IIa, IIb, and IIv), being the design lifetimes the main difference between blocks. The lifetimes ranged from the 2-year design of Block IIb to 3-year of Block IIv, with many spacecraft exceeding this (up to 4.5 years).These satellites are all 3-Axis stabilized spacecrafts with satellite mass of about 1 250 Kg, being equipped with a basic propulsion system to allow relocation within the constellation. They have improved time and frequency standards over the previous spacecraft prototypes, with increased frequency stability.

	*'''Second generation, GLONASS-M''' (or Uragan-M) is the second generation of satellites, where -M indicates modernized or modified. They were developed from 1990 on, with the first one sent into orbit in 2003. GLONASS-M satellites have a longer design lifetime of seven years as a result of propulsion system and clock stability (Cesium clocks) improvements. This is a big lifetime increase compared with the 2-3 years of previous first generation spacecraft, but it is still under the 10 years mean life of the GPS. These satellites have a mass of around 1 480 kg. Their size is of 2.4 m of diameter and 3.7 m in high, with dual solar arrays of 7.2 m. They also carry corner-cube laser reflectors for precise orbit determination and geodetic research. A remarkable feature of these satellites is the addition of a second civil signal on G2 band, which allows the civil users to cancel out the ionospheric refraction. On June 14, 2014 Russia placed into orbit into orbit a GLONASS-M satellite, carried there by a Soyuz 2-1b rocket from the Plesetsk Cosmodrome north of Moscow. This new GLONASS-M satellite is also equipped with an experimental payload capable of transmitting CDMA signals in the L3 frequency band (centered at 1202.025 MHz), contrary to the initial plans of including the CDMA signals transmission only on GLONASS-K third generation satellites.<ref>[http://gpsworld.com/russia-launches-single-glonass-satellite/ Russia Launches Single GLONASS Satellite], GPS World, GPS Staff, June 16, 2014</ref><ref>[http://~~www.~~insidegnss.com/~~node~~/~~4066~~ Russia Launches CDMA Payload on GLONASS-M], Inside GNSS, June 16, 2014</ref>		*'''Second generation, GLONASS-M''' (or Uragan-M) is the second generation of satellites, where -M indicates modernized or modified. They were developed from 1990 on, with the first one sent into orbit in 2003. GLONASS-M satellites have a longer design lifetime of seven years as a result of propulsion system and clock stability (Cesium clocks) improvements. This is a big lifetime increase compared with the 2-3 years of previous first generation spacecraft, but it is still under the 10 years mean life of the GPS. These satellites have a mass of around 1 480 kg. Their size is of 2.4 m of diameter and 3.7 m in high, with dual solar arrays of 7.2 m. They also carry corner-cube laser reflectors for precise orbit determination and geodetic research. A remarkable feature of these satellites is the addition of a second civil signal on G2 band, which allows the civil users to cancel out the ionospheric refraction. On June 14, 2014 Russia placed into orbit into orbit a GLONASS-M satellite, carried there by a Soyuz 2-1b rocket from the Plesetsk Cosmodrome north of Moscow. This new GLONASS-M satellite is also equipped with an experimental payload capable of transmitting CDMA signals in the L3 frequency band (centered at 1202.025 MHz), contrary to the initial plans of including the CDMA signals transmission only on GLONASS-K third generation satellites.<ref>[http://gpsworld.com/russia-launches-single-glonass-satellite/ Russia Launches Single GLONASS Satellite], GPS World, GPS Staff, June 16, 2014</ref><ref>[http://insidegnss.com/russia-launches-cdma-payload-on-glonass-m/ Russia Launches CDMA Payload on GLONASS-M], Inside GNSS, June 16, 2014</ref>
	[[File:K_model_at_Cebit_2011_Satellite.jpg\|Glonass K satellite at the CeBIT 2011 Expo in Germany\|300px\|thumb\|right]]		[[File:K_model_at_Cebit_2011_Satellite.jpg\|Glonass K satellite at the CeBIT 2011 Expo in Germany\|300px\|thumb\|right]]
	*'''Third generation''': The following generation of satellites, '''GLONASS-K''', has a service life of 10 years and a reduced weight of only 750Kg (allowing their launch in pairs from Plesetsk Cosmodrome on Soyuz-2-1a). This new generation of satellites includes, for the first time, code-division-multiple-access (CDMA) signals accompanying the legacy frequency-division-multiple-access signals.		*'''Third generation''': The following generation of satellites, '''GLONASS-K''', has a service life of 10 years and a reduced weight of only 750Kg (allowing their launch in pairs from Plesetsk Cosmodrome on Soyuz-2-1a). This new generation of satellites includes, for the first time, code-division-multiple-access (CDMA) signals accompanying the legacy frequency-division-multiple-access signals.


	Finally, the following table gathers the main characteristics of the different GLONASS satellite blocks:~~<ref name="GLONASS.it"/>~~		Finally, the following table gathers the main characteristics of the different GLONASS satellite blocks:

	{\| class="wikitable"		{\| class="wikitable"

Filipe.Pelica: Included editor logo.

2014-09-18T17:13:18Z

Included editor logo.

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Filipe.Pelica: GLONASS launch

2014-07-04T17:28:26Z

GLONASS launch

← Older revision		Revision as of 17:28, 4 July 2014
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	*'''First generation'''. The first true GLONASS satellites were launched between 1985 and 1990. They are divided into different block vehicles (Block IIa, IIb, and IIv), being the design lifetimes the main difference between blocks. The lifetimes ranged from the 2-year design of Block IIb to 3-year of Block IIv, with many spacecraft exceeding this (up to 4.5 years).These satellites are all 3-Axis stabilized spacecrafts with satellite mass of about 1 250 Kg, being equipped with a basic propulsion system to allow relocation within the constellation. They have improved time and frequency standards over the previous spacecraft prototypes, with increased frequency stability.		*'''First generation'''. The first true GLONASS satellites were launched between 1985 and 1990. They are divided into different block vehicles (Block IIa, IIb, and IIv), being the design lifetimes the main difference between blocks. The lifetimes ranged from the 2-year design of Block IIb to 3-year of Block IIv, with many spacecraft exceeding this (up to 4.5 years).These satellites are all 3-Axis stabilized spacecrafts with satellite mass of about 1 250 Kg, being equipped with a basic propulsion system to allow relocation within the constellation. They have improved time and frequency standards over the previous spacecraft prototypes, with increased frequency stability.

	*'''Second generation, GLONASS-M''' (or Uragan-M) is the second generation of satellites, where -M indicates modernized or modified. They were developed from 1990 on, with the first one sent into orbit in 2003. GLONASS-M satellites have a longer design lifetime of seven years as a result of propulsion system and clock stability (Cesium clocks) improvements. This is a big lifetime increase compared with the 2-3 years of previous first generation spacecraft, but it is still under the 10 years mean life of the GPS. These satellites have a mass of around 1 480 kg. Their size is of 2.4 m of diameter and 3.7 m in high, with dual solar arrays of 7.2 m. They also carry corner-cube laser reflectors for precise orbit determination and geodetic research. A remarkable feature of these satellites is the addition of a second civil signal on G2 band, which allows the civil users to cancel out the ionospheric refraction. On June 14, 2014 Russia placed into orbit into orbit a GLONASS-M satellite, carried there by a Soyuz 2-1b rocket from the Plesetsk Cosmodrome north of Moscow. This new GLONASS-M satellite is also equipped with an experimental payload capable of transmitting CDMA signals in the L3 frequency band (centered at 1202.025 MHz), contrary to the initial plans of including the CDMA signals transmission only on GLONASS-K third generation satellites.		*'''Second generation, GLONASS-M''' (or Uragan-M) is the second generation of satellites, where -M indicates modernized or modified. They were developed from 1990 on, with the first one sent into orbit in 2003. GLONASS-M satellites have a longer design lifetime of seven years as a result of propulsion system and clock stability (Cesium clocks) improvements. This is a big lifetime increase compared with the 2-3 years of previous first generation spacecraft, but it is still under the 10 years mean life of the GPS. These satellites have a mass of around 1 480 kg. Their size is of 2.4 m of diameter and 3.7 m in high, with dual solar arrays of 7.2 m. They also carry corner-cube laser reflectors for precise orbit determination and geodetic research. A remarkable feature of these satellites is the addition of a second civil signal on G2 band, which allows the civil users to cancel out the ionospheric refraction. On June 14, 2014 Russia placed into orbit into orbit a GLONASS-M satellite, carried there by a Soyuz 2-1b rocket from the Plesetsk Cosmodrome north of Moscow. This new GLONASS-M satellite is also equipped with an experimental payload capable of transmitting CDMA signals in the L3 frequency band (centered at 1202.025 MHz), contrary to the initial plans of including the CDMA signals transmission only on GLONASS-K third generation satellites.<ref>[http://gpsworld.com/russia-launches-single-glonass-satellite/ Russia Launches Single GLONASS Satellite], GPS World, GPS Staff, June 16, 2014</ref><ref>[http://www.insidegnss.com/node/4066 Russia Launches CDMA Payload on GLONASS-M], Inside GNSS, June 16, 2014</ref>
	[[File:K_model_at_Cebit_2011_Satellite.jpg\|Glonass K satellite at the CeBIT 2011 Expo in Germany\|300px\|thumb\|right]]		[[File:K_model_at_Cebit_2011_Satellite.jpg\|Glonass K satellite at the CeBIT 2011 Expo in Germany\|300px\|thumb\|right]]
	*'''Third generation''': The following generation of satellites, '''GLONASS-K''', has a service life of 10 years and a reduced weight of only 750Kg (allowing their launch in pairs from Plesetsk Cosmodrome on Soyuz-2-1a). This new generation of satellites includes, for the first time, code-division-multiple-access (CDMA) signals accompanying the legacy frequency-division-multiple-access signals.		*'''Third generation''': The following generation of satellites, '''GLONASS-K''', has a service life of 10 years and a reduced weight of only 750Kg (allowing their launch in pairs from Plesetsk Cosmodrome on Soyuz-2-1a). This new generation of satellites includes, for the first time, code-division-multiple-access (CDMA) signals accompanying the legacy frequency-division-multiple-access signals.

Filipe.Pelica: GLONASS launch

2014-07-04T17:24:04Z

GLONASS launch

← Older revision		Revision as of 17:24, 4 July 2014
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	*'''First generation'''. The first true GLONASS satellites were launched between 1985 and 1990. They are divided into different block vehicles (Block IIa, IIb, and IIv), being the design lifetimes the main difference between blocks. The lifetimes ranged from the 2-year design of Block IIb to 3-year of Block IIv, with many spacecraft exceeding this (up to 4.5 years).These satellites are all 3-Axis stabilized spacecrafts with satellite mass of about 1 250 Kg, being equipped with a basic propulsion system to allow relocation within the constellation. They have improved time and frequency standards over the previous spacecraft prototypes, with increased frequency stability.		*'''First generation'''. The first true GLONASS satellites were launched between 1985 and 1990. They are divided into different block vehicles (Block IIa, IIb, and IIv), being the design lifetimes the main difference between blocks. The lifetimes ranged from the 2-year design of Block IIb to 3-year of Block IIv, with many spacecraft exceeding this (up to 4.5 years).These satellites are all 3-Axis stabilized spacecrafts with satellite mass of about 1 250 Kg, being equipped with a basic propulsion system to allow relocation within the constellation. They have improved time and frequency standards over the previous spacecraft prototypes, with increased frequency stability.

	*'''Second generation, GLONASS-M''' (or Uragan-M) is the second generation of satellites, where -M indicates modernized or modified. They were developed from 1990 on, with the first one sent into orbit in 2003. GLONASS-M satellites have a longer design lifetime of seven years as a result of propulsion system and clock stability (Cesium clocks) improvements. This is a big lifetime increase compared with the 2-3 years of previous first generation spacecraft, but it is still under the 10 years mean life of the GPS. These satellites have a mass of around 1 480 kg. Their size is of 2.4 m of diameter and 3.7 m in high, with dual solar arrays of 7.2 m. They also carry corner-cube laser reflectors for precise orbit determination and geodetic research. A remarkable feature of these satellites is the addition of a second civil signal on G2 band, which allows the civil users to cancel out the ionospheric refraction.		*'''Second generation, GLONASS-M''' (or Uragan-M) is the second generation of satellites, where -M indicates modernized or modified. They were developed from 1990 on, with the first one sent into orbit in 2003. GLONASS-M satellites have a longer design lifetime of seven years as a result of propulsion system and clock stability (Cesium clocks) improvements. This is a big lifetime increase compared with the 2-3 years of previous first generation spacecraft, but it is still under the 10 years mean life of the GPS. These satellites have a mass of around 1 480 kg. Their size is of 2.4 m of diameter and 3.7 m in high, with dual solar arrays of 7.2 m. They also carry corner-cube laser reflectors for precise orbit determination and geodetic research. A remarkable feature of these satellites is the addition of a second civil signal on G2 band, which allows the civil users to cancel out the ionospheric refraction. On June 14, 2014 Russia placed into orbit into orbit a GLONASS-M satellite, carried there by a Soyuz 2-1b rocket from the Plesetsk Cosmodrome north of Moscow. This new GLONASS-M satellite is also equipped with an experimental payload capable of transmitting CDMA signals in the L3 frequency band (centered at 1202.025 MHz), contrary to the initial plans of including the CDMA signals transmission only on GLONASS-K third generation satellites.
	[[File:K_model_at_Cebit_2011_Satellite.jpg\|Glonass K satellite at the CeBIT 2011 Expo in Germany\|300px\|thumb\|right]]		[[File:K_model_at_Cebit_2011_Satellite.jpg\|Glonass K satellite at the CeBIT 2011 Expo in Germany\|300px\|thumb\|right]]
	*'''Third generation''': The following generation of satellites, '''GLONASS-K''', has a service life of 10 years and a reduced weight of only 750Kg (allowing their launch in pairs from Plesetsk Cosmodrome on Soyuz-2-1a). This new generation of satellites includes, for the first time, code-division-multiple-access (CDMA) signals accompanying the legacy frequency-division-multiple-access signals.		*'''Third generation''': The following generation of satellites, '''GLONASS-K''', has a service life of 10 years and a reduced weight of only 750Kg (allowing their launch in pairs from Plesetsk Cosmodrome on Soyuz-2-1a). This new generation of satellites includes, for the first time, code-division-multiple-access (CDMA) signals accompanying the legacy frequency-division-multiple-access signals.

Filipe.Pelica: PZ-90.11 update.

2014-07-04T17:13:05Z

PZ-90.11 update.

← Older revision		Revision as of 17:13, 4 July 2014
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	!Datum		!Datum
	\|align="center"\|PZ-90.02		\|align="center"\|PZ-90.11
	\|align="center"\|WGS-84		\|align="center"\|WGS-84
	\|align="center"\|GTRF		\|align="center"\|GTRF

Filipe.Pelica: fixed broken link

2014-05-29T14:24:14Z

fixed broken link

← Older revision		Revision as of 14:24, 29 May 2014
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	Satellites carry atomic clocks and the payload needed for handling (receiving, processing and transmitting) navigation data. They also have reflectors to allow laser ranging from dedicated ground stations.		Satellites carry atomic clocks and the payload needed for handling (receiving, processing and transmitting) navigation data. They also have reflectors to allow laser ranging from dedicated ground stations.

	Differences between GPS and GLONASS constellations are summarized in the following table:<ref name="GLONASS.it">[http://www.glonass.it/eng/glonass-story.aspx GLONASS System Description in glonass.it web site]</ref>		Differences between GPS and GLONASS constellations are summarized in the following table:<ref name="GLONASS.it">[http://www.glonass.it/eng/glonass-story.aspx/ GLONASS System Description in glonass.it web site]</ref>

	{\| class="wikitable"		{\| class="wikitable"

Filipe.Pelica: /* GLONASS Satellite Description */

2013-04-30T16:37:29Z

GLONASS Satellite Description

← Older revision		Revision as of 16:37, 30 April 2013
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	*'''First generation'''. The first true GLONASS satellites were launched between 1985 and 1990. They are divided into different block vehicles (Block IIa, IIb, and IIv), being the design lifetimes the main difference between blocks. The lifetimes ranged from the 2-year design of Block IIb to 3-year of Block IIv, with many spacecraft exceeding this (up to 4.5 years).These satellites are all 3-Axis stabilized spacecrafts with satellite mass of about 1 250 Kg, being equipped with a basic propulsion system to allow relocation within the constellation. They have improved time and frequency standards over the previous spacecraft prototypes, with increased frequency stability.		*'''First generation'''. The first true GLONASS satellites were launched between 1985 and 1990. They are divided into different block vehicles (Block IIa, IIb, and IIv), being the design lifetimes the main difference between blocks. The lifetimes ranged from the 2-year design of Block IIb to 3-year of Block IIv, with many spacecraft exceeding this (up to 4.5 years).These satellites are all 3-Axis stabilized spacecrafts with satellite mass of about 1 250 Kg, being equipped with a basic propulsion system to allow relocation within the constellation. They have improved time and frequency standards over the previous spacecraft prototypes, with increased frequency stability.

	*'''Second generation, GLONASS-M''' (or Uragan-M) is the second generation of satellites, where -M indicates modernized or modified. They were developed from 1990 on, with the first one sent into orbit in 2003~~, and a total of twenty satellites launched up to March 2010~~. GLONASS-M satellites have a longer design lifetime of seven years as a result of propulsion system and clock stability (Cesium clocks) improvements. This is a big lifetime increase compared with the 2-3 years of previous first generation spacecraft, but it is still under the 10 years mean life of the GPS. These satellites have a mass of around 1 480 kg. Their size is of 2.4 m of diameter and 3.7 m in high, with dual solar arrays of 7.2 m. They also carry corner-cube laser reflectors for precise orbit determination and geodetic research. A remarkable feature of these satellites is the addition of a second civil signal on G2 band, which allows the civil users to cancel out the ionospheric refraction.		*'''Second generation, GLONASS-M''' (or Uragan-M) is the second generation of satellites, where -M indicates modernized or modified. They were developed from 1990 on, with the first one sent into orbit in 2003. GLONASS-M satellites have a longer design lifetime of seven years as a result of propulsion system and clock stability (Cesium clocks) improvements. This is a big lifetime increase compared with the 2-3 years of previous first generation spacecraft, but it is still under the 10 years mean life of the GPS. These satellites have a mass of around 1 480 kg. Their size is of 2.4 m of diameter and 3.7 m in high, with dual solar arrays of 7.2 m. They also carry corner-cube laser reflectors for precise orbit determination and geodetic research. A remarkable feature of these satellites is the addition of a second civil signal on G2 band, which allows the civil users to cancel out the ionospheric refraction.
	[[File:K_model_at_Cebit_2011_Satellite.jpg\|Glonass K satellite at the CeBIT 2011 Expo in Germany\|300px\|thumb\|right]]		[[File:K_model_at_Cebit_2011_Satellite.jpg\|Glonass K satellite at the CeBIT 2011 Expo in Germany\|300px\|thumb\|right]]
	*'''Third generation''': The following generation of satellites, '''GLONASS-K''', has a service life of 10 years and a reduced weight of only 750Kg (allowing their launch in pairs from Plesetsk Cosmodrome on Soyuz-2-1a). This new generation of satellites includes, for the first time, code-division-multiple-access (CDMA) signals accompanying the legacy frequency-division-multiple-access signals.		*'''Third generation''': The following generation of satellites, '''GLONASS-K''', has a service life of 10 years and a reduced weight of only 750Kg (allowing their launch in pairs from Plesetsk Cosmodrome on Soyuz-2-1a). This new generation of satellites includes, for the first time, code-division-multiple-access (CDMA) signals accompanying the legacy frequency-division-multiple-access signals.

Filipe.Pelica: /* GLONASS Satellite Constellation */

2013-04-30T16:28:11Z

GLONASS Satellite Constellation

← Older revision		Revision as of 16:28, 30 April 2013
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	!GALILEO		!GALILEO
	\|-		\|-
	!Number of satellites		!Number of nominal satellites
			\|align="center"\|24
	\|align="center"\|24		\|align="center"\|24
	~~\|align="center"\|30~~
	\|align="center"\|30		\|align="center"\|30
	\|-		\|-

Teresa.Ferreira: /* GLONASS Satellite Description */

2012-06-19T15:07:05Z

GLONASS Satellite Description

← Older revision		Revision as of 15:07, 19 June 2012
Line 84:		Line 84:
	*'''Second generation, GLONASS-M''' (or Uragan-M) is the second generation of satellites, where -M indicates modernized or modified. They were developed from 1990 on, with the first one sent into orbit in 2003, and a total of twenty satellites launched up to March 2010. GLONASS-M satellites have a longer design lifetime of seven years as a result of propulsion system and clock stability (Cesium clocks) improvements. This is a big lifetime increase compared with the 2-3 years of previous first generation spacecraft, but it is still under the 10 years mean life of the GPS. These satellites have a mass of around 1 480 kg. Their size is of 2.4 m of diameter and 3.7 m in high, with dual solar arrays of 7.2 m. They also carry corner-cube laser reflectors for precise orbit determination and geodetic research. A remarkable feature of these satellites is the addition of a second civil signal on G2 band, which allows the civil users to cancel out the ionospheric refraction.		*'''Second generation, GLONASS-M''' (or Uragan-M) is the second generation of satellites, where -M indicates modernized or modified. They were developed from 1990 on, with the first one sent into orbit in 2003, and a total of twenty satellites launched up to March 2010. GLONASS-M satellites have a longer design lifetime of seven years as a result of propulsion system and clock stability (Cesium clocks) improvements. This is a big lifetime increase compared with the 2-3 years of previous first generation spacecraft, but it is still under the 10 years mean life of the GPS. These satellites have a mass of around 1 480 kg. Their size is of 2.4 m of diameter and 3.7 m in high, with dual solar arrays of 7.2 m. They also carry corner-cube laser reflectors for precise orbit determination and geodetic research. A remarkable feature of these satellites is the addition of a second civil signal on G2 band, which allows the civil users to cancel out the ionospheric refraction.
	[[File:K_model_at_Cebit_2011_Satellite.jpg\|Glonass K satellite at the CeBIT 2011 Expo in Germany\|300px\|thumb\|right]]		[[File:K_model_at_Cebit_2011_Satellite.jpg\|Glonass K satellite at the CeBIT 2011 Expo in Germany\|300px\|thumb\|right]]
	*'''Third generation''': The following generation of satellites, '''GLONASS-K''', has a service life of 10 years and a reduced weight of only 750Kg (allowing their launch in pairs from Plesetsk Cosmodrome on Soyuz-2-1a). This new generation of satellites includes, for the first time, code-division-multiple-access (CDMA) signals accompanying the legacy frequency-division-multiple-access signals. ~~There will be two versions:~~		*'''Third generation''': The following generation of satellites, '''GLONASS-K''', has a service life of 10 years and a reduced weight of only 750Kg (allowing their launch in pairs from Plesetsk Cosmodrome on Soyuz-2-1a). This new generation of satellites includes, for the first time, code-division-multiple-access (CDMA) signals accompanying the legacy frequency-division-multiple-access signals.
	**'''GLONASS-K1''' will transmit a CDMA signal located in the L3 band. The first GLONASS-K1 satellite was successfully launched on February 26 2011 <ref>[http://www.insidegnss.com/node/2487 Russia’s First GLONASS-K In Orbit, CDMA Signals Coming, InsideGNSS]</ref> and the new L3 CDMA signal is already being tracked by several receiver companies.<ref>[http://www.glonass-ianc.rsa.ru/en/content/news/?ELEMENT_ID=110 First GLONASS CDMA Signal on L3Tracked]</ref>
	**'''GLONASS-K2''' to be launched in 2013, will relocate the L3 signal to 1207.14 MHz and add an additional open CDMA signal located at 1575.42 MHz in the L1 band.
	A modernized GLONASS-K satellite, GLONASS-KM, for launch after 2015 <ref>[http://www.gpsworld.com/gnss-system/glonass/news/glonass-update-delves-constellation-details-10499 GLONASS Update Delves into Constellation Details, GPSworld]</ref> may also transmit on the GPS L5 frequency at 1179.45 MHz. An alternative to the present three-plane, equally spaced satellite constellation, is also under consideration.

	Finally, the following table gathers the main characteristics of the different GLONASS satellite blocks:<ref name="GLONASS.it"/>		Finally, the following table gathers the main characteristics of the different GLONASS satellite blocks:<ref name="GLONASS.it"/>