Launch date
March 21, 2020
34 OneWeb satellites
Launch vehicle
Launch site
Baikonur Cosmodrome, Kazakhstan
Prime contractor(s)
OneWeb Satellites
Low-Earth orbit


For its fourth mission of the year — and the second flight in 2020 with the Soyuz medium-lift launcher — Arianespace will perform the third launch for the OneWeb constellation, orbiting 34 satellites.

This 51st Soyuz mission conducted by Arianespace and its Starsem affiliate will be operated from the Baikonur Cosmodrome. It will pave the way for the constellation’s deployment phase – for which Arianespace is planned to perform 18 more medium-lift Soyuz launches from three spaceports (Kourou, Baikonur and Vostochny) during 2020 and 2021, without mentioning the Ariane 62 maiden flight.

By operating this third flight on behalf of the global satellite operator OneWeb, Arianespace participates in the fulfilment of its customer’s ultimate ambition: providing internet access for everyone, everywhere.

Washington, D.C.
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Universal Time (UTC)
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The OneWeb satellites

In June 2015, Arianespace and OneWeb signed an agreement for the deployment of Phase 1 of the eponymous constellation, covering 21 launches with the medium-lift Soyuz from three spaceports (Kourou in French Guiana; the Baikonur Cosmodrome in Kazakhstan; and Vostochny Cosmodrome in Russia) through 2020 and 2021.

On March 2019, Arianespace and OneWeb signed a new launch contract. The launch service agreement specifies the use of:

  • the qualification launch of the Ariane 62 version, scheduled by the end of 2020;
  • plus two Ariane 6 options (either in its Ariane 62 version, accommodating up to 36 OneWeb satellites, or in the Ariane 64 version with up to 78 OneWeb satellites) to be utilized, starting in 2023.

Flight ST28, the 28th Soyuz commercial mission from the Baikonur Cosmodrome performed by Arianespace and its Starsem affiliate, will put 34 OneWeb satellites into a near polar orbit at an altitude of 450 kilometers. After separation, the satellites will raise themselves to their operational orbit.

The initial six OneWeb satellites were successfully orbited by Arianespace on Soyuz Flight VS21 from French Guiana on February 27, 2019. On February 7, 2020, Arianespace and its Starsem affiliate launched successfully from Baikonour 34 OneWeb satellites on Soyuz Flight ST27.

OneWeb’s mission is to deliver global communications through a next-generation satellite constellation that will bring seamless connectivity to everyone, everywhere.

To achieve its purpose, OneWeb is building a network composed of low-Earth orbit satellites that will provide high-speed, low latency services to a wide range of customers in sectors that include aeronautics, maritime, backhaul services, community Wi-Fi, emergency response services and more. Central to its mission, OneWeb also will focus on connecting schools and bridging the digital divide for people everywhere.

Once deployed, the OneWeb constellation will enable user terminals capable of offering 3G, LTE, 5G and Wi-Fi coverage, providing high-speed access around the world – by air, sea and land.

OneWeb’s initial constellation is based on approximately 650 satellites as it grows to meet demand around the world. OneWeb will begin customer demos in 2020 and provide global, 24-hour coverage to customers in 2021.

OneWeb Satellites – a joint venture between OneWeb and Airbus Defence and Space – is the constellation’s prime contractor. The OneWeb spacecraft for Flight ST28 were built in OneWeb Satellites’ Florida-based series production line dedicated to the assembly, integration, and test of the OneWeb satellites. They will be the 41st to 74th OneWeb satellites to be launched by Arianespace.

With the launch of 34 OneWeb satellites on Flight ST28, Arianespace will have orbited a total of 201 spacecraft from Airbus Defence and Space. The Arianespace backlog of payloads still to be launched for Airbus Defence and Space (excluding the remaining OneWeb satellites) counts 21 additional payloads.

RUAG Space AB (Linköping, Sweden) is the prime contractor in charge of development and production of the dispenser system used on Flight ST28. It will carry the satellites during their flight to low Earth orbit and then release them into space.

This dedicated dispenser is designed to accommodate up to 36 spacecraft per launch, allowing Arianespace to timely deliver the lion’s share of the initial OneWeb constellation.

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