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O3b is a
satellite constellation A satellite constellation is a group of artificial satellites working together as a system. Unlike a single satellite, a constellation can provide permanent global or near-global coverage, such that at any time everywhere on Earth at least one ...
in
Medium Earth orbit A medium Earth orbit (MEO) is an Earth-centered orbit with an altitude above a low Earth orbit (LEO) and below a high Earth orbit (HEO) – between above sea level.
(MEO) owned and operated by SES, and designed to provide low-latency broadband connectivity to remote locations for mobile network operators and internet service providers, maritime, aviation, and government and defence. It is often referred to as O3b MEO to distinguish these satellites from SES's forthcoming
O3b mPOWER O3b mPOWER is a communications satellite system currently under construction and deployment. The first two satellites were launched on 16 December 2022 and commercial service is expected to begin in Q3 2023. Owned and operated by SES, O3b mPOWE ...
constellation. O3b originally stood for "other three billion", or the other three billion people at the time that did not have stable internet access, and the constellation was initially built, owned and operated by
O3b Networks O3b Networks Ltd. was a network communications service provider building and operating a medium Earth orbit (MEO) satellite constellation primarily intended to provide voice and data communications to mobile operators and Internet service pro ...
, which became a wholly owned subsidiary of SES in 2016 and ownership and operation of the constellation passed to SES Networks, a division of SES. The O3b MEO constellation began offering service in March 2014.


History

Initially planned to launch in 2010, the first four O3b satellites reached orbit on a
Soyuz-2 Soyuz-2 (GRAU index 14A14) is a modernized version of the Soviet Soyuz rocket. In its basic form, it is a three-stage launch vehicle for placing payloads into low Earth orbit. Compared to the previous versions of the Soyuz, the first-stage bo ...
/
Fregat-MT Fregat (russian: Фрегат, ''frigate'') is an upper stage developed by NPO Lavochkin in the 1990s, which is used in some Soyuz and Zenit launch vehicles, but is universal and can be used as a part of a medium and heavy class launch vehicl ...
launch vehicle A launch vehicle or carrier rocket is a rocket designed to carry a payload (spacecraft or satellites) from the Earth's surface to outer space. Most launch vehicles operate from a launch pads, supported by a launch control center and system ...
by
Arianespace Arianespace SA is a French company founded in 1980 as the world's first commercial launch service provider. It undertakes the operation and marketing of the Ariane programme. The company offers a number of different launch vehicles: the heavy-l ...
on 25 June 2013. After discovering a hardware defect in the initial satellites, O3b postponed the planned September 2013 launch of four additional satellites so repairs could be made. The second four satellites were launched by the same type of rocket from the Space Center in
French Guiana French Guiana ( or ; french: link=no, Guyane ; gcr, label= French Guianese Creole, Lagwiyann ) is an overseas department/region and single territorial collectivity of France on the northern Atlantic coast of South America in the Guianas. ...
, on 10 July 2014 and the O3b system started full commercial service on 1 September 2014. The third launch of four took place in December 2014, bringing the
satellite constellation A satellite constellation is a group of artificial satellites working together as a system. Unlike a single satellite, a constellation can provide permanent global or near-global coverage, such that at any time everywhere on Earth at least one ...
to 12 satellites. Four years later, four additional satellites were launched on 9 March 2018 on a
Soyuz-2.1b Soyuz-2 (GRAU index 14A14) is a modernized version of the Soviet Soyuz rocket. In its basic form, it is a three-stage launch vehicle for placing payloads into low Earth orbit. Compared to the previous versions of the Soyuz, the first-stage bo ...
rocket from the
Centre Spatial Guyanais The Guiana Space Centre (french: links=no, Centre spatial guyanais; CSG), also called Europe's Spaceport, is a European spaceport to the northwest of Kourou in French Guiana, a region of France in South America. Kourou is located approximat ...
. In December 2018,
Thales Alenia Space Thales Alenia Space () is a Franco-Italian aerospace manufacturer. A joint venture between the French technology corporation Thales Group (67%) and Italian defense conglomerate Leonardo (33%), the company is the largest satellite manufactur ...
said that tests on the final four O3b satellites would be completed by the end of January 2019 and the four satellites were successfully launched on 4 April 2019. In 2010, operators in the
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,
Pakistan Pakistan ( ur, ), officially the Islamic Republic of Pakistan ( ur, , label=none), is a country in South Asia. It is the world's fifth-most populous country, with a population of almost 243 million people, and has the world's second-lar ...
and
Nigeria Nigeria ( ), , ig, Naìjíríyà, yo, Nàìjíríà, pcm, Naijá , ff, Naajeeriya, kcg, Naijeriya officially the Federal Republic of Nigeria, is a country in West Africa. It is situated between the Sahel to the north and the Gulf of G ...
were among the first to prebook capacity on the O3b constellation to serve their respective markets. In 2010, O3b announced the selection of Europe Media Port to be the first provider of Gateway Teleport services for O3b's global network and a contract with Viasat for the production and installation of Ka-band infrastructure. In July 2014, SES Government Solutions, a subsidiary of (then O3b investor, now owner) SES, received approval to offer O3b services on their
General Services Administration The General Services Administration (GSA) is an independent agency of the United States government established in 1949 to help manage and support the basic functioning of federal agencies. GSA supplies products and communications for U.S. gove ...
(GSA) schedule allowing SES GS to be the first distribution partner to offer O3b capability directly to the
U.S. Government The federal government of the United States (U.S. federal government or U.S. government) is the national government of the United States, a federal republic located primarily in North America, composed of 50 states, a city within a feder ...
. In November 2014,
MS Quantum of the Seas ''Quantum of the Seas'' is a currently operated by Royal Caribbean International and is the lead ship of her class. At her time of delivery in 2014, ''Quantum of the Seas'' was the third largest cruise ship in the world by gross tonnage. She ...
became the first cruise ship to provide fast internet to guests through O3b Networks. The service is branded "Voom" by its cruise line,
Royal Caribbean International Royal Caribbean International (RCI), also formerly known as Royal Caribbean Cruise Line (RCCL), is a cruise line brand founded in 1968 in Norway and organised as a wholly owned subsidiary of Royal Caribbean Group since 1997. Based in Miami, Flori ...
and it was subsequently rolled out to every ship in their fleet. In August 2015, SES subsidiary, SES Government Solutions agreed on a one-year contract with US government scientific agency,
National Oceanic and Atmospheric Administration The National Oceanic and Atmospheric Administration (abbreviated as NOAA ) is an United States scientific and regulatory agency within the United States Department of Commerce that forecasts weather, monitors oceanic and atmospheric conditio ...
(NOAA) to supply O3b services and ground equipment to the
National Weather Service The National Weather Service (NWS) is an agency of the United States federal government that is tasked with providing weather forecasts, warnings of hazardous weather, and other weather-related products to organizations and the public for the ...
Office in
American Samoa American Samoa ( sm, Amerika Sāmoa, ; also ' or ') is an unincorporated territory of the United States located in the South Pacific Ocean, southeast of the island country of Samoa. Its location is centered on . It is east of the International ...
, expanding NOAA's broadband connectivity outside the continental United States to provide weather, water, and climate data, and forecasts and warnings to American Samoa. In August 2016, SES Government Solutions announced a contract to provide O3b's high throughput, low latency satellite communications for a
US Department of Defense The United States Department of Defense (DoD, USDOD or DOD) is an executive branch department of the federal government charged with coordinating and supervising all agencies and functions of the government directly related to national secur ...
end-user. The agreement is for a 365 days-per-year service consisting of a full-duplex symmetric 155 Mbit/s link, gateway access, a transportable 2.4 metre terminal, terrestrial backhaul, and maintenance and installation services, with a latency of under 200 milliseconds per round trip. The contract also provides for additional capacity to meet surge requirements. In June 2018, the
US Department of Defense The United States Department of Defense (DoD, USDOD or DOD) is an executive branch department of the federal government charged with coordinating and supervising all agencies and functions of the government directly related to national secur ...
signed a single-award blanket purchase agreement with SES Government Solutions for MEO high throughput, low latency satellite services including managed broadband services, gateway services, and monitoring and control services, to a maximum of US$516.7 million over a five-year period. In September 2019, SES became a
Microsoft Azure Microsoft Azure, often referred to as Azure ( , ), is a cloud computing platform operated by Microsoft for application management via around the world-distributed data centers. Microsoft Azure has multiple capabilities such as software as a ...
ExpressRoute services partner to provide dedicated, private network connectivity from sea vessels, aircraft, and industrial or government sites anywhere in the world to the Azure cloud computing service, via both its geostationary satellites and O3b MEO satellites. In September 2020, SES and Microsoft announced that SES was the
medium Earth orbit A medium Earth orbit (MEO) is an Earth-centered orbit with an altitude above a low Earth orbit (LEO) and below a high Earth orbit (HEO) – between above sea level.
connectivity partner for the Microsoft Azure Orbital ground station service that enables network operators to control their satellite operations and capacity from within the Azure cloud computing service. Under their agreement, SES and Microsoft will jointly invest in Azure Orbital ground stations for the MEO and Earth Observation segments, initially in the United States, which will be installed and managed by SES. Also, satellite telemetry, tracking and control systems and data ground stations for the forthcoming
O3b mPOWER O3b mPOWER is a communications satellite system currently under construction and deployment. The first two satellites were launched on 16 December 2022 and commercial service is expected to begin in Q3 2023. Owned and operated by SES, O3b mPOWE ...
satellites will be located with Microsoft's Azure edge sites to provide O3b mPOWER customers with "one-hop" access to Azure cloud services. In October 2020, international charity hospital ships provider,
Mercy Ships Mercy Ships is an international charity that operates the largest non-governmental hospital ships in the world, providing humanitarian aid like free health care, community development projects, community health education, mental health programs, ...
announced it will be using SES's Signature Maritime connectivity services via O3b satellites to provide remote viewing and diagnosis, and remote training on board the Global Mercy, the world's largest civilian hospital ship. In February 2021, SES announced two contracts with the
US Department of Defense The United States Department of Defense (DoD, USDOD or DOD) is an executive branch department of the federal government charged with coordinating and supervising all agencies and functions of the government directly related to national secur ...
as part of the June 2018 blanket purchase agreement. One is for a portable O3b service to support forward-deployed military personnel and the second to provide O3b mission-critical communications without using a commercial gateway in remote locations in Southwest Asia, managed and controlled from an SES Network Operations Center. Also in February 2021, SES announced that its Signature Cruise broadband connectivity via O3b will be used on
Virgin Voyages Virgin Voyages is a cruise line headquartered in Plantation, Florida and a joint venture between the Virgin Group and Bain Capital. As of April 2022, Virgin Voyages has two ships in the fleet, with two more on order, all with an expected capac ...
' latest ships Scarlet Lady and Valiant Lady to provide passengers with free fast onboard wi-fi internet access. In June 2021, SES joined the
Amazon Web Services Amazon Web Services, Inc. (AWS) is a subsidiary of Amazon that provides on-demand cloud computing platforms and APIs to individuals, companies, and governments, on a metered pay-as-you-go basis. These cloud computing web services provide ...
Direct Connect Delivery Partner programme, using the O3b constellation (and SES' fleet of
geostationary A geostationary orbit, also referred to as a geosynchronous equatorial orbit''Geostationary orbit'' and ''Geosynchronous (equatorial) orbit'' are used somewhat interchangeably in sources. (GEO), is a circular geosynchronous orbit in altitude ...
satellites) to provide customers access to AWS cloud-based applications and services from locations around the world with limited or no terrestrial communications, and to provide the cloud provider a backup network if their infrastructure fails. In August 2021,
Microsoft Microsoft Corporation is an American multinational technology corporation producing computer software, consumer electronics, personal computers, and related services headquartered at the Microsoft Redmond campus located in Redmond, Washingt ...
became the first cloud provider customer for O3b, with Microsoft buying managed satellite connectivity services from SES for the
Microsoft Azure Microsoft Azure, often referred to as Azure ( , ), is a cloud computing platform operated by Microsoft for application management via around the world-distributed data centers. Microsoft Azure has multiple capabilities such as software as a ...
cloud computing service. Microsoft is initially using the existing first generation O3b satellites, before upgrading to the faster broadband speeds from the forthcoming
O3b mPOWER O3b mPOWER is a communications satellite system currently under construction and deployment. The first two satellites were launched on 16 December 2022 and commercial service is expected to begin in Q3 2023. Owned and operated by SES, O3b mPOWE ...
satellites when they come into operation in 2022. (In November 2022, SES announced that the start of the O3b mPOWERservice was delayed until Q3 2023). In December 2021, SES's wholly owned subsidiary SES Government Solutions announced that the US Army has conducted trials of commercial
satellite constellation A satellite constellation is a group of artificial satellites working together as a system. Unlike a single satellite, a constellation can provide permanent global or near-global coverage, such that at any time everywhere on Earth at least one ...
s in multiple orbits, including the O3b satellite system, as part of the effort to establish Multi-Domain Operations. In December 2021,
Honeywell Honeywell International Inc. is an American publicly traded, multinational conglomerate corporation headquartered in Charlotte, North Carolina. It primarily operates in four areas of business: aerospace, building technologies, performance ma ...
,
Hughes Network Systems Hughes Network Systems, LLC is a wholly owned subsidiary of EchoStar. It is headquartered in Germantown, Maryland and provides satellite internet service. HughesNet has over 1.3 million subscribers in the Americas. History Hughes Communications ...
and SES demonstrated multi-orbit high-speed airborne connectivity for military customers using Honeywell's JetWave MCX terminal and a Hughes HM-series modem, and SES satellites in both
medium Earth orbit A medium Earth orbit (MEO) is an Earth-centered orbit with an altitude above a low Earth orbit (LEO) and below a high Earth orbit (HEO) – between above sea level.
(MEO) and
geostationary orbit A geostationary orbit, also referred to as a geosynchronous equatorial orbit''Geostationary orbit'' and ''Geosynchronous (equatorial) orbit'' are used somewhat interchangeably in sources. (GEO), is a circular geosynchronous orbit in altitud ...
(GEO). The tests achieved full duplex data rates of more than 40 megabits per second via a number of SES' (GEO) satellites including GovSat-1, and the O3b
satellite constellation A satellite constellation is a group of artificial satellites working together as a system. Unlike a single satellite, a constellation can provide permanent global or near-global coverage, such that at any time everywhere on Earth at least one ...
, with connections moving between GEO/MEO links in under 30 sec. In May 2022, in conjunction with
Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia to the north and west, China to the east, Kyrgyzstan to the southeast, Uzbekis ...
i mobile network operator,
Kcell Kcell (KASE: KCEL) is the Cellular Communication Operator in Kazakhstan, part of Kazakhtelecom. The company was founded in 1998 and provides cellular services under the Kcell brand, which is mainly focused on the corporate segment, and Activ, ...
, SES used the O3b satellite constellation to demonstrate that MEO satellites could be used to provide high-speed 3G and 4G connectivity to remote regions of Kazakhstan for reliable video calling, conferencing and streaming, and web browsing, with a latency five times lower than on the existing platform based on
geostationary orbit A geostationary orbit, also referred to as a geosynchronous equatorial orbit''Geostationary orbit'' and ''Geosynchronous (equatorial) orbit'' are used somewhat interchangeably in sources. (GEO), is a circular geosynchronous orbit in altitud ...
satellites.


Satellites

The satellites are deployed in a circular orbit along the equator at an altitude of (
medium Earth orbit A medium Earth orbit (MEO) is an Earth-centered orbit with an altitude above a low Earth orbit (LEO) and below a high Earth orbit (HEO) – between above sea level.
) at a velocity of approximately , each making 5 orbits a day. Due to problems with a component of the first four satellites launched, three of those four have been placed on standby. Each satellite is equipped with twelve fully steerable
Ka-band The Ka band (pronounced as either "kay-ay band" or "ka band") is a portion of the microwave part of the electromagnetic spectrum defined as frequencies in the range 26.5–40 gigahertz (GHz), i.e. wavelengths from slightly over one centime ...
antennas (two beams for gateways, ten beams for remotes) that use 4.3
GHz The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, meaning that one he ...
of spectrum (2 × 216 MHz per beam) with a proposed throughput of 1.6  Gbit/s per beam (800 
Mbit/s In telecommunications, data-transfer rate is the average number of bits (bitrate), characters or symbols (baudrate), or data blocks per unit time passing through a communication link in a data-transmission system. Common data rate units are multi ...
per direction), resulting in a total capacity of 16 Gbit/s per satellite. Each beam's footprint measures in diameter. O3b claims a mouth-to-ear one-way latency of 179 milliseconds for voice communication, and an end-to-end round-trip latency of 140 ms for data services. The maximum throughput per TCP connection is 2.1 Mbit/s. For maritime applications, O3b claims a round-trip latency of 140 ms, and connectivity speeds of over 500 Mbit/s. The satellites are powered by
gallium arsenide Gallium arsenide (GaAs) is a III-V direct band gap semiconductor with a zinc blende crystal structure. Gallium arsenide is used in the manufacture of devices such as microwave frequency integrated circuits, monolithic microwave integrated circui ...
solar arrays A photovoltaic system, also PV system or solar power system, is an electric power system designed to supply usable solar power by means of photovoltaics. It consists of an arrangement of several components, including solar panels to absorb and c ...
and
lithium-ion batteries A lithium-ion or Li-ion battery is a type of rechargeable battery which uses the reversible reduction of lithium ions to store energy. It is the predominant battery type used in portable consumer electronics and electric vehicles. It also sees ...
and weigh approximately each. The satellites were constructed by
Thales Alenia Space Thales Alenia Space () is a Franco-Italian aerospace manufacturer. A joint venture between the French technology corporation Thales Group (67%) and Italian defense conglomerate Leonardo (33%), the company is the largest satellite manufactur ...
, a division of
Thales Group Thales Group () is a French multinational company that designs, develops and manufactures electrical systems as well as devices and equipment for the aerospace, defence, transportation and security sectors. The company is headquartered in Paris' ...
. The first satellite (PFM) was built in the
Cannes Mandelieu Space Center The Cannes Mandelieu Space Center is an industrial plant dedicated to spacecraft manufacturing, located in both the towns of Cannes and Mandelieu in France. After a long history in aircraft manufacturing, starting in 1929, the center became incr ...
, while the rest of the constellation was assembled, integrated and tested in Thales Alenia Space Italy's Roman facilities. In September 2017, SES announced the next generation of O3b satellites and placed an order for an initial seven from
Boeing Satellite Systems The Boeing Satellite Development Center is a major business unit of Boeing Defense, Space & Security. It brought together Boeing satellite operations with that of GM Hughes Electronics' Space and Communications division in El Segundo, Califo ...
using a new satellite platform based on Boeing's 702 line of scalable buses. Expected to launch in 2021, the
O3b mPOWER O3b mPOWER is a communications satellite system currently under construction and deployment. The first two satellites were launched on 16 December 2022 and commercial service is expected to begin in Q3 2023. Owned and operated by SES, O3b mPOWE ...
constellation of
medium Earth orbit A medium Earth orbit (MEO) is an Earth-centered orbit with an altitude above a low Earth orbit (LEO) and below a high Earth orbit (HEO) – between above sea level.
(MEO) satellites for broadband internet services will "be able to deliver anywhere from hundreds of megabits to 10 gigabits to any ship at sea" through 30,000 spot beams. Software-defined routing will direct traffic between the mPOWER MEO satellites and SES'
geostationary A geostationary orbit, also referred to as a geosynchronous equatorial orbit''Geostationary orbit'' and ''Geosynchronous (equatorial) orbit'' are used somewhat interchangeably in sources. (GEO), is a circular geosynchronous orbit in altitude ...
fleet. In August 2020, SES contracted
Boeing The Boeing Company () is an American multinational corporation that designs, manufactures, and sells airplanes, rotorcraft, rockets, satellites, telecommunications equipment, and missiles worldwide. The company also provides leasing and produc ...
to build four additional O3b mPOWER satellites and
SpaceX Space Exploration Technologies Corp. (SpaceX) is an American spacecraft manufacturer, launcher, and a satellite communications corporation headquartered in Hawthorne, California. It was founded in 2002 by Elon Musk with the stated goal of ...
was contracted for an additional two launches, to make four launches for the whole O3b mPOWER constellation in 2022–2024.


List of satellites


Use of medium Earth orbit

O3b MEO is currently the only
high-throughput satellite High-throughput satellite (HTS) is a communications satellite that provides more throughput than a classic FSS satellite (at least twice, though usually by a factor of 20 or more) for the same amount of allocated orbital spectrum, thus significan ...
(HTS) system for
internet services An Internet service provider (ISP) is an organization that provides services for accessing, using, or participating in the Internet. ISPs can be organized in various forms, such as commercial, community-owned, non-profit, or otherwise privat ...
to use the medium Earth orbit; most other existing and proposed systems use satellites in either
geosynchronous orbit A geosynchronous orbit (sometimes abbreviated GSO) is an Earth-centered orbit with an orbital period that matches Earth's rotation on its axis, 23 hours, 56 minutes, and 4 seconds (one sidereal day). The synchronization of rotation and orbital ...
(GEO) or
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 mor ...
(LEO). Although previous satellite internet services primarily used geosynchronous satellites (SES has four geostationary HTS in orbit –
Astra 2E Astra 2E is one of the Astra communications satellites owned and operated by SES S.A., launched to the Astra 28.2°E orbital position on 30 September 2013 after a 10-week delay caused by launcher problems. The satellite provides free-to-ai ...
,
SES-12 SES-12 is a geostationary communications satellite operated by SES S.A. Satellite description SES-12 was designed and manufactured by Airbus Defence and Space. It has a mass of and has a design life of at least 15 years. Launch SES-12 wa ...
,
SES-14 SES-14 is a geostationary communications satellite operated by SES S.A. at 47.5° West, replaces NSS-806, and designed and manufactured by Airbus Defence and Space. The satellite launched on 25 January 2018 at 22:20 UTC along with the Global ...
and SES-15), demand for increased bandwidth and for lower latency has shifted the focus for HTS to lower orbits.''Large LEO satellite constellations: Will it be different this time?''
McKinsey & Company, 4 May 2020, Accessed 29 October 2020
The lower the altitude of the orbit, the closer the satellite is to the Earth and the lower the latency and
path loss Path loss, or path attenuation, is the reduction in power density (attenuation) of an electromagnetic wave as it propagates through space. Path loss is a major component in the analysis and design of the link budget of a telecommunication system. ...
es (enabling lower ground station and satellite power, and costs for the same throughput)''LEO constellations and tracking challenges''
Satellite Evolution Group, September 2017, Accessed 30 October 2020
The
propagation delay Propagation delay is the time duration taken for a signal to reach its destination. It can relate to networking, electronics or physics. ''Hold time'' is the minimum interval required for the logic level to remain on the input after triggering e ...
for a round-trip
internet protocol The Internet Protocol (IP) is the network layer communications protocol in the Internet protocol suite for relaying datagrams across network boundaries. Its routing function enables internetworking, and essentially establishes the Internet. I ...
transmission via a geosynchronous satellite can be over 550 ms, and such latency is the bane of digital connectivity, in particular for automated stock trades, hardcore gaming and
Skype Skype () is a proprietary telecommunications application operated by Skype Technologies, a division of Microsoft, best known for VoIP-based videotelephony, videoconferencing and voice calls. It also has instant messaging, file transfer, debit ...
video chats.''Real-Time Latency: Rethinking Remote Networks''
Telesat, February 2020, Accessed 31 October 2020
''LEO and MEO broadband constellations mega source of consternation''
SpaceNews, 13 March 2018, Accessed 29 October 2020
So, many proposed non-geosynchronous satellite internet services have adopted a low Earth orbit of under 2000 km altitude where latency can be as little 40ms, and by 2018 more than 18,000 new LEO satellites had been proposed to launch by 2025. However, a lower orbit also has drawbacks; satellites move faster relative to the ground and can "see" a smaller area of the
Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surface ...
, and so for continuous widespread access require a constellation of many satellites, with complex constellation management and tracking by the ground stations. Medium Earth orbit, although higher in altitude than LEO is nevertheless much lower than geosynchronous orbit and so shares many of the advantages of LEO while reducing its drawbacks:''The Gravity of Space Debris''
Via Satellite. March 2019, Accessed 31 October 2020
* Latency as low as 125ms – longer than LEO but substantial improvement over GEO satellites * Longer orbital period than LEO – a smaller constellation needed for continuous "visibility" * Cheaper and simpler telemetry, tracking and control systems than LEO * Higher "look angle" from the ground than LEOs * Longer service life expectancy than LEO satellites * Reduced
Doppler shift The Doppler effect or Doppler shift (or simply Doppler, when in context) is the change in frequency of a wave in relation to an observer who is moving relative to the wave source. It is named after the Austrian physicist Christian Doppler, who d ...
problem than LEO * Less orbital overcrowding and space debris than LEO


See also

*
SES S.A. SES S.A. is a Luxembourgish-French satellite telecommunications network provider supplying video and data connectivity worldwide to broadcasters, content and internet service providers, mobile and fixed network operators, governments and insti ...
*
O3b Networks O3b Networks Ltd. was a network communications service provider building and operating a medium Earth orbit (MEO) satellite constellation primarily intended to provide voice and data communications to mobile operators and Internet service pro ...
*
O3b mPOWER O3b mPOWER is a communications satellite system currently under construction and deployment. The first two satellites were launched on 16 December 2022 and commercial service is expected to begin in Q3 2023. Owned and operated by SES, O3b mPOWE ...


References

{{Orbital launches in 2018 Communications satellite constellations Spacecraft launched in 2013 Spacecraft launched in 2014 Spacecraft launched in 2018 First artificial satellites of a country SES S.A. Satellites of Luxembourg Spacecraft launched by Soyuz-2 rockets