Molniya (satellite): Difference between revisions
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{{Short description|Soviet military surveillance and communications satellites}} |
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{{about|the satellite system|the Soviet design bureaux|NPO Molniya}} |
{{about|the satellite system|the Soviet design bureaux|NPO Molniya|the launch vehicle|Molniya (rocket)}} |
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{{Use British English|date=October 2020}} |
{{Use British English|date=October 2020}} |
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|launched = 164 <ref name=st>{{cite web|url=https://www.space-track.org/#catalog |title=Satellite Catalog |website=Space-Track.org |publisher=SAIC | |
|launched = 164 <ref name=st>{{cite web|url=https://www.space-track.org/#catalog |title=Satellite Catalog |website=Space-Track.org |publisher=SAIC |access-date=22 February 2019}}</ref> |
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The '''Molniya''' ({{lang-rus|Молния|p=ˈmolnʲɪjə|a=Ru-молния.ogg}}, "Lightning") series satellites |
The '''Molniya''' ({{lang-rus|Молния|p=ˈmolnʲɪjə|a=Ru-молния.ogg}}, "Lightning") series satellites were [[military]] and [[communications satellites]] launched by the [[Soviet Union]] from 1965 to 1991, and by the [[Russian Federation]] from 1991 to 2004. These satellites used highly [[Orbital eccentricity|eccentric]] elliptical orbits known as [[Molniya orbit]]s, which have a long dwell time over high latitudes. They are suited for communications purposes in polar regions, in the same way that [[geostationary satellites]] are used for equatorial regions.<ref name="Martin2000">{{cite book|last=Martin|first=Donald H.|title=Communication Satellites|url=https://books.google.com/books?id=_azf94TByF8C&pg=PA218|access-date=1 January 2013|year=2000|publisher=AIAA|isbn=9781884989094|pages=215–}}</ref> |
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There were 164 Molniya satellites launched, all in Molniya orbits with the exception of Molniya 1S which was launched into [[geostationary orbit]] for testing purposes.<ref>{{cite web|url=https://space.skyrocket.de/doc_sdat/molniya-1s.htm |publisher=Gunter's Space Page |title=Molniya-1S |author=Gunter Dirk Krebs}}</ref><ref>https://www.globalsecurity.org/space/world/russia/geo.htm</ref> |
There were 164 Molniya satellites launched, all in Molniya orbits with the exception of Molniya 1S which was launched into [[geostationary orbit]] for testing purposes.<ref>{{cite web|url=https://space.skyrocket.de/doc_sdat/molniya-1s.htm |publisher=Gunter's Space Page |title=Molniya-1S |author=Gunter Dirk Krebs}}</ref><ref>{{Cite web|url=https://www.globalsecurity.org/space/world/russia/geo.htm|title=Geosynchronous Orbits - Russia and Communications Satellite Systems}}</ref> |
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==History== |
==History== |
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In the early 1960s, when Europe and America |
In the early 1960s, when Europe and America were establishing [[Geostationary satellites|geostationary communication satellites]], the Russians found these orbits unsuitable.<ref name=rsw>{{cite web|author=Anatoly Zak |url=http://www.russianspaceweb.com/spacecraft_comsats.html |title=Russian communications satellites |publisher=Russian Space Web |access-date=22 May 2018}}</ref> They were limited in the amount of rocket power available and it is extremely energy intensive to both launch a satellite to 40,000 km, and [[Orbital inclination change|change its inclination]] to be over the equator, especially when launched from Russia. Additionally geostationary satellites give poor coverage in polar regions. A large portion of Russian territory consists of polar regions, making this arrangement further unfavorable to Russian interests.<ref>{{Cite web|url=http://www.braeunig.us/space/orbmech.htm#maneuver|title=Basics of Space Flight: Orbital Mechanics|website=www.braeunig.us|author=Robert A. Braeunig|access-date=6 March 2019|archive-url=https://web.archive.org/web/20120204054322/http://www.braeunig.us/space/orbmech.htm#maneuver|archive-date=4 February 2012|url-status=dead}}</ref> As a result, [[Energia (corporation)|OKB-1]] sought to find a more optimal orbit for the satellite. Studies found that this could be achieved using a large elliptical orbit, with an [[Apsis|apogee]] over Russian territory.<ref name=rsw/> The satellite's name, "quick as lightning", is in reference to the speed with which it passes through the perigee.<ref>{{cite book|isbn=9783319034164|title=Handbook of Satellite Orbits: From Kepler to GPS|last1=Capderou|first1=Michel|date=2014-04-23|page=393|publisher=Springer }}</ref> |
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| ⚫ | Molniya series satellites were replaced (succeeded) by the [[Meridian (satellite)|'''Meridian series''']], with the first launch in 2006.<ref name="meridian">{{cite web |last=Zak |first=Anatoly |title=The Meridian satellite (14F112) |url=http://www.russianspaceweb.com/meridian.html |url-status=dead |archive-url=https://web.archive.org/web/20110526025425/http://www.russianspaceweb.com/meridian.html |archive-date=26 May 2011 |access-date=3 May 2011 |work=RussianSpaceWeb}}</ref> {{As of|2023}}, there are currently 36 Molniya satellites left in orbit.<ref>{{cite web |title=SatCat: Molniya payload search |url=https://www.space-track.org/#catalog |publisher=Space Track}}</ref> |
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| ⚫ | |||
| ⚫ | The Molniya |
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| ⚫ | |||
| ⚫ | The early Molniya-1 satellites were designed for television, telegraph and telephone across |
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{{main|Molniya 1}} |
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| ⚫ | The Molniya programme was authorized on 30 October 1961 and design was handled by OKB-1.<ref name=seh>{{cite book|page=416|url=https://books.google.com/books?id=2ZNxDwAAQBAJ&q=molniya+orbit+OKB-1+history&pg=PA416|isbn=978-1-85109-514-8|title=Space Exploration and Humanity: A Historical Encyclopedia|volume=1|author=History Committee of the American Astronautical Society|editor=Stephen B. Johnson|publisher=Greenwood Publishing Group|date=2010-08-23|access-date=17 April 2019}}</ref><ref name=mol2>{{cite web|url=http://www.astronautix.com/m/molniya-2.html |archive-url=https://web.archive.org/web/20161228055658/http://astronautix.com/m/molniya-2.html |url-status=dead |archive-date=28 December 2016 |website=astronautix.com|title=Molniya-2|author=Mark Wade}}</ref> They were based on the [[KAUR (satellite bus)|KAUR-2 satellite bus]], with design finishing in 1963. The first launch took place on 4 June 1964 and ended in failure when the 8K78 booster core stage lost thrust 287 seconds into launch due to a jammed servo motor. The next attempt was on 22 August 1964 and reached orbit successfully, but the parabolic communications antennas did not properly deploy due to a design flaw in the release mechanism. Publicly referred to as [[Kosmos 41]], it nonetheless operated for nine months. The first operational satellite, Molniya 1-1, was successfully launched on 23 April 1965.<ref name=seh/> By 30 May 1966, the third Molniya 1 had taken the [[first images of Earth from space|first images of the whole Earth]] in history.<ref>{{cite news|url=https://www.washingtonpost.com/blogs/achenblog/post/spaceship-earth-the-first-photos/2012/01/03/gIQAzXF5XP_blog.html|title=Spaceship Earth: The first photos|author=Joel Achenbach|newspaper=[[The Washington Post]] |date=3 January 2012|access-date=16 June 2020}}</ref> |
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| ⚫ | They had a lifespan of approximately 1.5 years, as their orbits were disrupted by [[Orbital perturbation analysis|perturbations]], as well as deteriorating solar arrays and they had to be constantly replaced.<ref name="exam">{{cite conference|url=http://issfd.org/ISSFD_2009/CollisionRiskII/Kolyuka.pdf |
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| ⚫ | The early Molniya-1 satellites were designed for television, telegraph and telephone across Russia,<ref name=seh/> but they were also fitted with cameras used for weather monitoring, and possibly for assessing clear areas for [[Zenit (satellite)|Zenit spy satellites]].<ref>{{cite web|title=A History of Soviet/Russian Meteorological Satellites|url=http://www.bis-space.com/belgium/wp-content/uploads/2015/05/meteor.pdf|first=Bart|last=Hendrickx|page=66|website=bis-space.com|location=Antwerpen, Belgium|access-date=22 February 2019|archive-date=27 March 2018|archive-url=https://web.archive.org/web/20180327212247/http://www.bis-space.com/belgium/wp-content/uploads/2015/05/meteor.pdf|url-status=dead}}</ref> The system was operational by 1967, with the construction of the [[Orbita (TV system)|Orbita]] groundstations.<ref name=seh/> |
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| ⚫ | |||
| ⚫ | They had a lifespan of approximately 1.5 years, as their orbits were disrupted by [[Orbital perturbation analysis|perturbations]], as well as deteriorating solar arrays and they had to be constantly replaced.<ref name="exam">{{cite conference|url=http://issfd.org/ISSFD_2009/CollisionRiskII/Kolyuka.pdf|title=Examination of the Lifetime, Evolution and Re-Entry Features for the "Molniya" Type Orbits|date=28 September 2009|first1=Yu. F.|last1=Kolyuka|first2=N.M.|last2=Ivanov|first3=T.I.|last3=Afanasieva|first4=T.A.|last4=Gridchina|access-date=22 May 2018|page=2|publisher=Mission Control Center 4, Korolev, Moscow |location=Toulouse, France|conference=21st International Symposium of Space Flight Dynamics}}</ref><ref name=seh/><ref>{{cite book|url=https://books.google.com/books?id=Jf-odeaeoqkC&q=molniya+orbit+OKB-1+history&pg=PA515|page=510|isbn=978-0-16-081733-5|title=Rockets and People, Volume III, Hot Days of the Cold War|publisher=Government Printing Office }}</ref> |
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| ⚫ | |||
In total 94 Molniya 1 series satellites were launched, with the last going up in 2004.<ref name=st/> |
In total 94 Molniya 1 series satellites were launched, with the last going up in 2004.<ref name=st/> |
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==Molniya 2== |
== Molniya 2 == |
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The first Molniya 2 satellites were tested from 1971 with the first operational satellite launching in 1974 from [[Plesetsk Cosmodrome|Plesetsk]]. The used the same satellite bus and basic design as later model Molniya 1 satellites, but with an expanded number of users under the military's [[Unified System of Satellite Communications (YeSSS) program]]. Development was difficult because the final satellite bus was unpressurized, changing their selection of radios.<ref name=mol2/> |
The first Molniya 2 satellites were tested from 1971 with the first operational satellite launching in 1974 from [[Plesetsk Cosmodrome|Plesetsk]]. The used the same satellite bus and basic design as later model Molniya 1 satellites, but with an expanded number of users under the military's [[Unified System of Satellite Communications (YeSSS) program]]. Development was difficult because the final satellite bus was unpressurized, changing their selection of radios.<ref name=mol2/> |
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Only seventeen Molniya 2 series satellite were launched, as they were soon superseded by the Molniya 3.<ref name=st/> |
Only seventeen Molniya 2 series satellite were launched, as they were soon superseded by the Molniya 3.<ref name=st/> |
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==Molniya 3== |
== Molniya 3 == |
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| ⚫ | Originally called the '''Molniya-2M''', their development began in 1972, with launches from 1974. They were also based on the KAUR-2 bus, launching solely from Plesetsk. Earlier models were used for civilian communications in a similar orbit, but different purpose, to the military-only Molniya-1 satellites. From 1980s they were used by the military, and by the 1990s they were operated in the same manner as the Molniya 1 satellites.<ref>{{cite web|url=http://www.astronautix.com/m/molniya-3.html|archive-url=https://web.archive.org/web/20161228034158/http://astronautix.com/m/molniya-3.html|url-status=dead|archive-date=28 December 2016|website=astronautix.com|author=Mark Wade|title=Molniya-3}}</ref> |
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| ⚫ | Originally called the Molniya-2M, their development began in 1972, with launches from 1974. They were also based on the KAUR-2 bus, launching solely from Plesetsk. Earlier models were used for civilian communications in a similar orbit, but different purpose, to the military-only Molniya-1 satellites. From 1980s they were used by the military, and by the 1990s they were operated in the same manner as the Molniya 1 satellites.<ref>{{cite web|url=http://www.astronautix.com/m/molniya-3.html |website= |
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A total of 53 Molniya 3 series satellites were launched, with the last one going up in 2003.<ref name=st/> |
A total of 53 Molniya 3 series satellites were launched, with the last one going up in 2003.<ref name=st/> |
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==Orbital Properties== |
== Orbital Properties == |
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| ⚫ | [[File:molniya.jpg|thumb|Groundtrack of Molniya orbit. In the operational part of the orbit (4 hours on each side of apogee), the satellite is north of 55.5° N (latitude of for example central Scotland, [[Moscow]] and southern part of Hudson Bay). A satellite in this orbits spends most of its time in the northern hemisphere and passes quickly over the southern hemisphere.]] |
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{{main|Molniya orbit}} |
{{main|Molniya orbit}} |
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| ⚫ | [[File:molniya.jpg|thumb|290px|Groundtrack of Molniya orbit. In the operational part of the orbit (4 hours on each side of apogee), the satellite is north of 55.5° N (latitude of for example central Scotland, [[Moscow]] and southern part of Hudson Bay). A satellite in this orbits spends most of its time in the northern hemisphere and passes quickly over the southern hemisphere.]] |
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A typical Molniya series satellite, has: |
A typical Molniya series satellite, has: |
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| ⚫ | |||
| ⚫ | |||
* Eccentricity: 0.74 |
* Eccentricity: 0.74 |
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* Inclination: 63.4° <ref name="exam"/> |
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* Inclination: 63.4°<ref name="exam">{{cite conference|url=http://issfd.org/ISSFD_2009/CollisionRiskII/Kolyuka.pdf |title=Examination of the Lifetime, Evolution and Re-Entry Features for the "Molniya" Type Orbits |date=28 September 2009|first1=Yu. F.|last1=Kolyuka|first2=N.M.|last2=Ivanov|first3=T.I.|last3=Afanasieva|first4=T.A.|last4=Gridchina |accessdate=22 May 2018 |page=2 |publisher=Mission Control Center 4, Korolev, Moscow |location=Toulouse, France|conference=21st International Symposium of Space Flight Dynamics}}</ref> |
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* Argument of perigee: 270° |
* Argument of perigee: 270° |
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* Period: 718 minutes<ref name="art">{{cite journal|page=517 |
* Period: 718 minutes <ref name="art">{{cite journal|page=517|date=18 August 1989|journal=Journal of Atmospheric and Oceanic Technology|volume=7|title=On the Use of Satellites in Molniya Orbits of Meteorological Observation of Middle and High Latitudes|first1=Stanley Q.|last1=Kidder|first2=Thomas H.|last2=Vonder Haar|issue=3|doi=10.1175/1520-0426(1990)007<0517:OTUOSI>2.0.CO;2|bibcode=1990JAtOT...7..517K |doi-access=free}}</ref> |
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===Inclination=== |
=== Inclination === |
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In general, the [[oblate spheroid|oblateness]] of the Earth [[Orbital perturbation analysis|perturbs the argument of perigee]] (<math>\omega</math>), so that even if the apogee started near the north pole, it would gradually move unless constantly corrected with station-keeping thruster burns. Keeping the dwell point over Russia, and useful for communications necessitated without excessive fuel use meant that the satellites [[frozen orbit|needed an inclination of 63.4°]], for which these perturbations are zero.<ref name="smad">{{cite |
In general, the [[oblate spheroid|oblateness]] of the Earth [[Orbital perturbation analysis|perturbs the argument of perigee]] (<math>\omega</math>), so that even if the apogee started near the north pole, it would gradually move unless constantly corrected with station-keeping thruster burns. Keeping the dwell point over Russia, and useful for communications necessitated without excessive fuel use meant that the satellites [[frozen orbit|needed an inclination of 63.4°]], for which these perturbations are zero.<ref name="smad">{{cite book|title=Space Mission Analysis and Design |editor=Wiley J. Larson and James R. Wertz |bibcode=1999smad.book.....W |last1=Wertz |first1=James Richard |last2=Larson |first2=Wiley J. |year=1999 }}</ref><ref name="art"/> |
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===Period=== |
=== Period === |
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Similarly, to ensure the ground track repeats every 24 hours the [[nodal period]] needed to be half a [[sidereal day]]. |
Similarly, to ensure the ground track repeats every 24 hours the [[nodal period]] needed to be half a [[sidereal day]]. |
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===Eccentricity=== |
=== Eccentricity === |
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To maximise the dwell time the eccentricity, the differences in altitudes of the apogee and perigee, [[Kepler's laws of planetary motion#Second law of Kepler|had to be large]]. |
To maximise the dwell time the eccentricity, the differences in altitudes of the apogee and perigee, [[Kepler's laws of planetary motion#Second law of Kepler|had to be large]]{{Broken anchor|date=2024-09-06|bot=User:Cewbot/log/20201008/configuration|target_link=Kepler's laws of planetary motion#Second law of Kepler|reason= The anchor (Second law of Kepler) [[Special:Diff/968688731|has been deleted]].}}. |
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However, the perigee needed to be far enough above the atmosphere to avoid drag, and the orbital period needed to be approximately half a sidereal day. These two factors constrained the eccentricity to become approximately 0.737.<ref name="art"/> |
However, the perigee needed to be far enough above the atmosphere to avoid drag, and the orbital period needed to be approximately half a sidereal day. These two factors constrained the eccentricity to become approximately 0.737.<ref name="art"/> |
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== |
== References == |
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| ⚫ | Molniya series satellites were replaced by the [[Meridian (satellite)|Meridian series]], with the first launch in 2006.<ref name="meridian">{{cite web| |
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==References== |
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{{Reflist}} |
{{Reflist}} |
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==External links== |
== External links == |
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{{Commons category|Molniya (communications satellite)}} |
{{Commons category|Molniya (communications satellite)}} |
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*[https://web.archive.org/web/20080516082459/http://www.astronautix.com/craft/molniya1.htm Molniya-1 spacecraft] |
* [https://web.archive.org/web/20080516082459/http://www.astronautix.com/craft/molniya1.htm Molniya-1 spacecraft] |
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*[http://www.daviddarling.info/encyclopedia/M/Molniya.html Molniya: A short history of development] |
* [http://www.daviddarling.info/encyclopedia/M/Molniya.html Molniya: A short history of development] |
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*[https://fas.org/spp/guide/russia/comm/elliptical/molniya.htm Molniya constellation] |
* [https://fas.org/spp/guide/russia/comm/elliptical/molniya.htm Molniya constellation] {{Webarchive|url=https://web.archive.org/web/20160813224247/https://fas.org/spp/guide/russia/comm/elliptical/molniya.htm |date=13 August 2016 }} |
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*[https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1966-092A Molniya 1-4] |
* [https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1966-092A Molniya 1-4] |
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[[Category:Soviet military spacecraft]] |
[[Category:Soviet military spacecraft]] |
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[[Category:Satellites using the KAUR bus]] |
[[Category:Satellites using the KAUR bus]] |
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[[Category:Satellite series]] |
[[Category:Satellite series]] |
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[[Category:Satellites in Molniya orbit]] |
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Latest revision as of 03:42, 23 September 2024
 Molniya 1 | |||
| Manufacturer | Experimental Design Bureau (OKB-1) | ||
|---|---|---|---|
| Country of origin | USSR | ||
| Operator | Experimental Design Bureau (OKB-1) | ||
| Applications | Communications and surveillance | ||
| Specifications | |||
| Bus | KAUR-2 | ||
| Launch mass | 1,600 kg (3,500 lb) | ||
| Dimensions | 4.4 m tall, 1.4 m base diameter [1] | ||
| Power | 6 solar panels + batteries [1] | ||
| Regime | Molniya orbit | ||
| Design life | 1.5 to 5 years | ||
| Production | |||
| Status | Retired | ||
| Launched | 164 [2] | ||
| Maiden launch | Molniya 1-1, 23 April 1965 [2] | ||
| Last launch | Molniya 1-93, 18 February 2004 [1] | ||
| |||
The Molniya (Russian: Молния, IPA: [ˈmolnʲɪjə] , "Lightning") series satellites were military and communications satellites launched by the Soviet Union from 1965 to 1991, and by the Russian Federation from 1991 to 2004. These satellites used highly eccentric elliptical orbits known as Molniya orbits, which have a long dwell time over high latitudes. They are suited for communications purposes in polar regions, in the same way that geostationary satellites are used for equatorial regions.[3]
There were 164 Molniya satellites launched, all in Molniya orbits with the exception of Molniya 1S which was launched into geostationary orbit for testing purposes.[4][5]
History
[edit]In the early 1960s, when Europe and America were establishing geostationary communication satellites, the Russians found these orbits unsuitable.[6] They were limited in the amount of rocket power available and it is extremely energy intensive to both launch a satellite to 40,000 km, and change its inclination to be over the equator, especially when launched from Russia. Additionally geostationary satellites give poor coverage in polar regions. A large portion of Russian territory consists of polar regions, making this arrangement further unfavorable to Russian interests.[7] As a result, OKB-1 sought to find a more optimal orbit for the satellite. Studies found that this could be achieved using a large elliptical orbit, with an apogee over Russian territory.[6] The satellite's name, "quick as lightning", is in reference to the speed with which it passes through the perigee.[8]
Molniya series satellites were replaced (succeeded) by the Meridian series, with the first launch in 2006.[9] As of 2023[update], there are currently 36 Molniya satellites left in orbit.[10]
Molniya 1
[edit]The Molniya programme was authorized on 30 October 1961 and design was handled by OKB-1.[11][12] They were based on the KAUR-2 satellite bus, with design finishing in 1963. The first launch took place on 4 June 1964 and ended in failure when the 8K78 booster core stage lost thrust 287 seconds into launch due to a jammed servo motor. The next attempt was on 22 August 1964 and reached orbit successfully, but the parabolic communications antennas did not properly deploy due to a design flaw in the release mechanism. Publicly referred to as Kosmos 41, it nonetheless operated for nine months. The first operational satellite, Molniya 1-1, was successfully launched on 23 April 1965.[11] By 30 May 1966, the third Molniya 1 had taken the first images of the whole Earth in history.[13]
The early Molniya-1 satellites were designed for television, telegraph and telephone across Russia,[11] but they were also fitted with cameras used for weather monitoring, and possibly for assessing clear areas for Zenit spy satellites.[14] The system was operational by 1967, with the construction of the Orbita groundstations.[11]
They had a lifespan of approximately 1.5 years, as their orbits were disrupted by perturbations, as well as deteriorating solar arrays and they had to be constantly replaced.[15][11][16]
By the 1970s, the Molniya 1 series (and the upgrade Molniya 1T) was mostly used for military communications, with civilian communications moving to Molniya 2.[11]
In total 94 Molniya 1 series satellites were launched, with the last going up in 2004.[2]
Molniya 2
[edit]The first Molniya 2 satellites were tested from 1971 with the first operational satellite launching in 1974 from Plesetsk. The used the same satellite bus and basic design as later model Molniya 1 satellites, but with an expanded number of users under the military's Unified System of Satellite Communications (YeSSS) program. Development was difficult because the final satellite bus was unpressurized, changing their selection of radios.[12]
These satellites were used in the Soviet national Orbita television network, which had been established a few years earlier in 1967.[12]
Only seventeen Molniya 2 series satellite were launched, as they were soon superseded by the Molniya 3.[2]
Molniya 3
[edit]Originally called the Molniya-2M, their development began in 1972, with launches from 1974. They were also based on the KAUR-2 bus, launching solely from Plesetsk. Earlier models were used for civilian communications in a similar orbit, but different purpose, to the military-only Molniya-1 satellites. From 1980s they were used by the military, and by the 1990s they were operated in the same manner as the Molniya 1 satellites.[17]
A total of 53 Molniya 3 series satellites were launched, with the last one going up in 2003.[2]
Orbital Properties
[edit]
A typical Molniya series satellite, has:
- Semi-major axis: 26,600 km
- Eccentricity: 0.74
- Inclination: 63.4° [15]
- Argument of perigee: 270°
- Period: 718 minutes [18]
Inclination
[edit]In general, the oblateness of the Earth perturbs the argument of perigee (), so that even if the apogee started near the north pole, it would gradually move unless constantly corrected with station-keeping thruster burns. Keeping the dwell point over Russia, and useful for communications necessitated without excessive fuel use meant that the satellites needed an inclination of 63.4°, for which these perturbations are zero.[19][18]
Period
[edit]Similarly, to ensure the ground track repeats every 24 hours the nodal period needed to be half a sidereal day.
Eccentricity
[edit]To maximise the dwell time the eccentricity, the differences in altitudes of the apogee and perigee, had to be large[broken anchor].
However, the perigee needed to be far enough above the atmosphere to avoid drag, and the orbital period needed to be approximately half a sidereal day. These two factors constrained the eccentricity to become approximately 0.737.[18]
References
[edit]- ^ a b c John Pike (ed.). "Molniya". Global Security.org.
- ^ a b c d e "Satellite Catalog". Space-Track.org. SAIC. Retrieved 22 February 2019.
- ^ Martin, Donald H. (2000). Communication Satellites. AIAA. pp. 215–. ISBN 9781884989094. Retrieved 1 January 2013.
- ^ Gunter Dirk Krebs. "Molniya-1S". Gunter's Space Page.
- ^ "Geosynchronous Orbits - Russia and Communications Satellite Systems".
- ^ a b Anatoly Zak. "Russian communications satellites". Russian Space Web. Retrieved 22 May 2018.
- ^ Robert A. Braeunig. "Basics of Space Flight: Orbital Mechanics". www.braeunig.us. Archived from the original on 4 February 2012. Retrieved 6 March 2019.
- ^ Capderou, Michel (23 April 2014). Handbook of Satellite Orbits: From Kepler to GPS. Springer. p. 393. ISBN 9783319034164.
- ^ Zak, Anatoly. "The Meridian satellite (14F112)". RussianSpaceWeb. Archived from the original on 26 May 2011. Retrieved 3 May 2011.
- ^ "SatCat: Molniya payload search". Space Track.
- ^ a b c d e f History Committee of the American Astronautical Society (23 August 2010). Stephen B. Johnson (ed.). Space Exploration and Humanity: A Historical Encyclopedia. Vol. 1. Greenwood Publishing Group. p. 416. ISBN 978-1-85109-514-8. Retrieved 17 April 2019.
- ^ a b c Mark Wade. "Molniya-2". astronautix.com. Archived from the original on 28 December 2016.
- ^ Joel Achenbach (3 January 2012). "Spaceship Earth: The first photos". The Washington Post. Retrieved 16 June 2020.
- ^ Hendrickx, Bart. "A History of Soviet/Russian Meteorological Satellites" (PDF). bis-space.com. Antwerpen, Belgium. p. 66. Archived from the original (PDF) on 27 March 2018. Retrieved 22 February 2019.
- ^ a b Kolyuka, Yu. F.; Ivanov, N.M.; Afanasieva, T.I.; Gridchina, T.A. (28 September 2009). Examination of the Lifetime, Evolution and Re-Entry Features for the "Molniya" Type Orbits (PDF). 21st International Symposium of Space Flight Dynamics. Toulouse, France: Mission Control Center 4, Korolev, Moscow. p. 2. Retrieved 22 May 2018.
- ^ Rockets and People, Volume III, Hot Days of the Cold War. Government Printing Office. p. 510. ISBN 978-0-16-081733-5.
- ^ Mark Wade. "Molniya-3". astronautix.com. Archived from the original on 28 December 2016.
- ^ a b c Kidder, Stanley Q.; Vonder Haar, Thomas H. (18 August 1989). "On the Use of Satellites in Molniya Orbits of Meteorological Observation of Middle and High Latitudes". Journal of Atmospheric and Oceanic Technology. 7 (3): 517. Bibcode:1990JAtOT...7..517K. doi:10.1175/1520-0426(1990)007<0517:OTUOSI>2.0.CO;2.
- ^ Wertz, James Richard; Larson, Wiley J. (1999). Wiley J. Larson and James R. Wertz (ed.). Space Mission Analysis and Design. Bibcode:1999smad.book.....W.
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