OneWeb has finished its initial satellite constellation buildout, as India and its space agency, the Indian Space Research Organisation (ISRO), made its second orbital flight of 2023 by flying 36 of the company’s satellites aboard its LVM3 (previously known as the GSLV Mk III) launch vehicle from the Satish Dhawan Space Centre.
The launch occurred on Sunday, March 26 at 03:30 UTC (9:00 AM IST). The LVM3 flew southward into a near-polar trajectory from the Second Launch Pad on Sriharikota Island in the Bay of Bengal, and the satellites are destined for a 1,200 km circular orbit inclined 86.4 degrees to the equator.
This flight was the LVM3’s sixth overall flight and the second flight involving OneWeb payloads, after the successful OneWeb flight 14 launch in October 2022. The LVM3 is comparable to launchers like the Atlas V or Ariane 5, using liquid stages and a pair of large solid rocket boosters.
The LVM3 uses two hypergolic-fueled Vikas engines on its L110 core stage, with two C200 solid rocket boosters mounted onto the stage. After the SRBs are jettisoned, the cryogenic upper stage separates from the core and powers the LVM’s payload to orbit.
The upper stage, known as the C25, is powered by a CE-20 engine that uses liquid hydrogen and liquid oxygen as its propellants. In time, the C25 will be replaced by the C32 stage, which uses an updated version of the CE-20, and that will be restartable in orbit. The LVM3 will also undergo further refinements to human-rate the vehicle for the Gaganyaan capsule’s crewed flights in the coming years.
Before this launch, OneWeb had 578 operational broadband communication satellites in orbit. This mission, OneWeb’s 18th flight overall, takes the number of operational spacecraft to 614. This passes the 588 satellite threshold the company states is needed to offer worldwide broadband service, which the company is mainly targeting for the enterprise, transportation, and government sectors.
This mission also completed OneWeb’s first-generation constellation, making OneWeb the first of the major new low Earth orbit broadband services to complete its satellite network. OneWeb plans to orbit 648 first-generation satellites in total, with the spacecraft launched after this mission becoming on-orbit spares.
OneWeb was founded by Greg Wyler in 2012 as WorldVu Satellites Ltd. in the UK’s Channel Islands. In 2014, the company obtained approval for the frequencies it would use and began exploring sites to manufacture its proposed satellites. It took seven years to launch the company’s first test satellite.
The company, now merging with Eutelsat, is owned by multiple shareholders — including Bharti Global of India and the UK Government — after bankruptcy proceedings in 2020. The company started operational launches of its constellation that year with its booking of Soyuz launches through Arianespace.
However, the Russian invasion of Ukraine in 2022 and subsequent sanctions caused the company to switch to providers such as SpaceX and ISRO’s NewSpace India Limited (NSIL) commercial arm. 36 OneWeb satellites that had been ready for launch from Baikonur within days of the invasion were also seized and have not been returned.
Despite this setback, OneWeb was able to continue building out its constellation with its satellite manufacturing plant at Merritt Island, Florida, and with flights aboard the Falcon 9 and the LVM3. This launch would be the third of 2023 for the company and the 18th overall.
The satellites themselves mass approximately 150 kg each and use the Ku-band at 12-18 GHz to provide broadband services to customers. They use the Ka-band to link to gateway ground stations. The spacecraft needs to link to these ground stations to provide service, as there are no inter-satellite links with these spacecraft.
The satellites are also equipped with a magnetic grappling fixture to enable a future spacecraft to latch onto them for deorbiting. In addition, they have fuel allocated for deorbit purposes, as they orbit at too high an altitude to passively deorbit within a reasonable timeframe.
This flight, although it completes the first generation satellite constellation, is not the last flight OneWeb plans for this year. A second-generation demonstration satellite is scheduled to fly aboard OneWeb flight 19 on a SpaceX Falcon 9 no earlier than this coming May. 15 first-generation satellites will fly as on-orbit spares as well as five Iridium Next satellites.
OneWeb engineers will be conducting a test campaign after the constellation is completed with this flight. Service is available now in many areas, but the company plans to begin worldwide broadband service by the fourth quarter of 2023.
(Lead image: LVM3 lifts off from the Satish Dhawan Space Centre. Credit: ISRO)