SEATTLE/PARIS (Reuters) – A rocket carrying six satellites built by Airbus SE and partner OneWeb blasted off from French Guiana on Wednesday, the first step in a plan to give millions of people in remote and rural areas high-speed internet beamed down from space. While hall thrusters are not widely used on designs for military satellites, they have been used in the commercial satellite communications arena by companies like Space Systems/Loral, which uses.
SEATTLE/PARIS, Feb 27 (Reuters) - A rocket carrying six satellites built by Airbus SE and partner OneWeb was due to blast off from French Guiana on Wednesday, the first step in a plan to give millions of people in remote and rural areas access to high-speed internet beamed down from space.
A successful launch could mark a new era in the satellite services industry, with companies like Elon Musk's SpaceX, LeoSat Enterprises, and Canada's Telesat enabling data networks with hundreds or even thousands of tiny satellites that orbit closer to Earth than traditional communications satellites - a radical shift made possible by leaps in laser technology and computer chips.
The launch may presage a boom in demand for launch services, with a handful of venture-backed rocket companies developing smaller boosters to deploy the smaller satellites at lower cost.
'We are looking in the next five years at potentially 10,000 satellites needing to be launched and we don't have the launch capacity at this moment to do that,' aerospace consultancy Teal Group analyst Marco Caceres said.
The Russia-built Soyuz rocket was set for liftoff from Kourou, French Guiana, at 6:37 p.m. (2137 GMT), carrying satellites made by the Airbus-OneWeb joint venture called OneWeb Satellites in Toulouse, France.
OneWeb and others aim to expand the availability and speed of satellite-based internet compared to existing providers such as Hughes Network Systems, whose network is in a higher-altitude geostationary orbit. Hughes is also an investor in OneWeb and helping to build out its ground infrastructure.
OneWeb has raised more than $2 billion from investors including Airbus, Coca-Cola, Virgin Group, Qualcomm Inc and SoftBank. It aims to have global broadband coverage in 2021 from about 650 satellites.
OneWeb plans to begin launching more than 30 satellites at a time every month starting as early as September so its constellation is nearly 25 percent complete by year-end, a person with direct knowledge of the project said.
Other firms say they are not far behind. Telesat, backed by Loral Space & Communications Inc, is targeting 2022 for broadband services from nearly 300 satellites.
Washington, D.C.-based LeoSat Enterprises says it has already signed more than $1 billion in pre-launch provisional agreements for secure data transfers for global banks, telecoms providers and governments beginning in 2022.
FAST ASSEMBLY REQUIRED
Reuters reported a major shake-up last year at SpaceX's Starlink project, which Chief Executive Elon Musk has said is critical as a funding source for his broader space transportation ambitions but faces challenges on development and testing.
A person with direct knowledge of the program said SpaceX was driving toward a first 'production launch' with money-making satellites in mid-2019.
A SpaceX official said its initial batch of satellites were currently being manufactured, and its internal launch targets were on track, but the company has not announced a launch date.
The OneWeb project has forced Airbus to rethink the way it builds satellites, overhauling a painstaking, bespoke effort to introduce industrial methods and speed using assembly lines and automation.
The two companies plan to open what they say is the world's first satellite mass-production factory at Florida's Kennedy Space Center in March for $85 million. Production will ramp up to 15 satellites per week at a cost of $1 million per satellite, executives say.
OneWeb Satellites Chief Executive Officer Tony Gingiss told Reuters the goal is to be making two to three satellites a day by early summer.
'That's revolutionary in an industry where it costs $50 million to build one satellite and normally takes months and a team of engineers to do,' Gingiss said.
OneWeb has ground stations in Canada, Italy and Norway that allow the satellites to communicate with Earth, and has signed a partnership with Qualcomm to develop the technology that links the internet from space to different users, such as airlines. (Reporting by Eric M. Johnson in Seattle Additional reporting by Tim Hepher in Paris; Editing by Greg Mitchell and Sonya Hepinstall)
A satellite constellation is a group of artificial satellites working in concert. Such a constellation can be considered to be a number of satellites with coordinated ground coverage, operating together under shared control, synchronized so that they overlap well in coverage, the period in which a satellite or other spacecraft is visible above the local horizon.
Low Earth orbiting satellites (LEOs) are often deployed in satellite constellations, because the coverage area provided by a single LEO satellite only covers a small area that moves as the satellite travels at the high angular velocity needed to maintain its orbit. Many LEO satellites are needed to maintain continuous coverage over an area. This contrasts with geostationary satellites, where a single satellite, moving at the same angular velocity as the rotation of the Earth's surface, provides permanent coverage over a large area.
Examples of satellite constellations include the Global Positioning System (GPS), Galileo and GLONASS constellations for navigation and geodesy, the Iridium and Globalstar satellite telephony services, the Disaster Monitoring Constellation and RapidEye for remote sensing, the Orbcomm messaging service, Russian elliptic orbitMolniya and Tundra constellations, the large-scale Teledesic, Skybridge, and Celestribroadband constellation proposals of the 1990s, and more recent systems such as O3b or the OneWeb proposal.
Broadband applications benefit from low-latency communications, so LEO satellite constellations provide an advantage over a geostationary satellite, where minimum theoretical latency from ground to satellite is about 125 milliseconds, compared to 1–4 milliseconds for a LEO satellite. A LEO satellite constellation can also provide more system capacity by frequency reuse across its coverage, with spot beam frequency use being analogous to the minimum number of satellites needed to provide a service, and their orbits—is a field in itself.
A group of formation-flying satellites very close together and moving in almost identical orbits is known as a satellite cluster or Satellite formation flying.
In 2015 Farooq Khan then the President of Samsung Research America published a research paper providing details how a large satellite broadband constellation can be designed.[2]
There are a large number of constellations that may satisfy a particular mission. Usually constellations are designed so that the satellites have similar orbits, eccentricity and inclination so that any perturbations affect each satellite in approximately the same way. In this way, the geometry can be preserved without excessive station-keeping thereby reducing the fuel usage and hence increasing the life of the satellites. Another consideration is that the phasing of each satellite in an orbital plane maintains sufficient separation to avoid collisions or interference at orbit plane intersections. Circular orbits are popular, because then the satellite is at a constant altitude requiring a constant strength signal to communicate.
A class of circular orbit geometries that has become popular is the Walker Delta Pattern constellation.This has an associated notation to describe it which was proposed by John Walker.[3] His notation is:
where:i is the inclination;t is the total number of satellites;p is the number of equally spaced planes; andf is the relative spacing between satellites in adjacent planes. The change in true anomaly (in degrees) for equivalent satellites in neighbouring planes is equal to f*360/t.
For example, the Galileo Navigation system is a Walker Delta 56°:24/3/1 constellation. This means there are 24 satellites in 3 planes inclined at 56 degrees, spanning the 360 degrees around the equator. The '1' defines the phasing between the planes, and how they are spaced. The Walker Delta is also known as the Ballard rosette, after A. H. Ballard's similar earlier work.[4][5] Ballard's notation is (t,p,m) where m is a multiple of the fractional offset between planes.
Another popular constellation type is the near-polar Walker Star, which is used by Iridium. Here, the satellites are in near-polar circular orbits across approximately 180 degrees, travelling north on one side of the Earth, and south on the other. The active satellites in the full Iridium constellation form a Walker Star of 86.4°:66/6/2, i.e. the phasing repeats every two planes. Walker uses similar notation for stars and deltas, which can be confusing.
At least eight telecommunications satellite constellations are in-development in LEO and MEO :[6]
Constellation | Number | Manufacturer | Weight | Unveil. | Avail. | Orbit | User speed | Band | Inter-satellite links | Status |
---|---|---|---|---|---|---|---|---|---|---|
Iridium Next | 66 +9 spares | Thales Alenia + Orbital ATK | 860 kg 1,900 lb | 2009 | 2018 | 780 km 485 mi | 1.4 Mbit/s | L (1 – 2 GHz) Ka (26.5 – 40 GHz) | K 23 GHz [8] | Complete |
Boeing | 1,396-2,956 | Boeing Satellite | N/A | 2016 | N/A | 1,200 km 745 mi | broadband | V (40 – 75 GHz) | none [9][10] | transferring the application to OneWeb[7] |
LeoSat | 78-108 | Thales Alenia | 1,250 kg 2,755 lb | 2015 | 2022 | 1,400 km 895 mi | in increments of 100 Mbit/s | Ka (26.5 – 40 GHz) | optical[11] | first launches in 2021[12] |
OneWeb constellation | 882-1980[13] | OneWeb AirbusJV | 145 kg 320 lb | 2015 | 2020[14] | 1,200 km 745 mi | up to 595 Mbit/s[14] | Ku (12–18 GHz) Ka (26.5 – 40 GHz) | none [15][16] | 6 pilot satellites in February 2019 |
SpaceX Starlink | 4,425-11,943 | SpaceX | 227 kg | 2015 | 2020[17] | 550-1,325 km 341-823 mi | up to 1 Gbit/s[18] | Ku (12–18 GHz) Ka (26.5 – 40 GHz) | optical[19] | First batch of 60 satellites launched in May 2019 |
O3b, bought by SES S.A. in 2016 | 20 O3b 7 O3bm | Thales Alenia (O3b) Boeing (O3bm) | 700 kg: O3b 1,543 lb | 2008: O3b 2017: O3bm | 2014: O3b 2021: O3bm | 8,000 km 4,970 mi | 1 Gbit/s for a cruise ship | Ka (26.5 – 40 GHz) | none | O3b complete |
Telesat LEO | 117-512[20] | Airbus SSTL SS/Loral[a] | N/A | 2016 | 2021 | 1,000–1,248 km 621–775 mi | fiber-optic cable-like | Ka (26.5 – 40 GHz) | optical[21][22] | two prototypes: 2018 launch |
CASICHongyun[23] | 156 | 2017 | 2022 | 160–2,000 km 99–1,243 mi | prototype launched in December 2018[24] | |||||
CASCHongyan[25] | 320 | 2017 | 2023 | 1,100 km 680 mi | prototype launched in December 2018[26] |
Wikimedia Commons has media related to Satellite constellation. |
Satellite constellation simulation tools:
More information: