In collaboration with Starsem and Roscosmos, Arianespace has launched 34 new Internet communications satellites aboard the Soyuz 2.1b for the OneWeb 9 mission. The flight marks the eighth operational launch of OneWeb satellites and will bring the total number in orbit to 288: 48% of the 600 satellites required for global coverage with 48 Additional spare part in orbit for the total size of the first-stage constellation up to 648 satellites.
The launch was scheduled for Thursday, August 19. However, a rare scrub was called seconds before takeoff. The second attempt has been scheduled for the first time on Friday. Takeoff took place on Saturday, August 21st from the 6/31st Baikonur Cosmodrome in Kazakhstan at 22:13:40 UTC (18:13:40 EDT).
for this task, The Soyuz 2.1b is equipped with an upper stage Fregat motor that is powered by asymmetric dimethylhydrazine (UDMH) and nitrogen tetraoxide (N2O4). It is capable of placing OneWeb’s 5,518 kg payload into its initial orbit of approximately 450 km at an inclination of 84.7 degrees.
OneWeb’s satellite constellation is a global internet and broadband platform in action similar to Starlink from SpaceX The Amazon Kuiper Project. The goal of the constellation is to provide near-low latency Internet to sites where terrestrial Internet is unavailable or unreliable. Once finished, OneWeb will provide Internet access with speeds of up to 50MB/s anywhere in the world, including land, sea and air.
After the first stage is completed, OneWeb will move to the second stage, which will consist of 6,372 satellites; This number is significantly lower than the company’s previous proposal, which consists of about 48,000 satellites.
Each OneWeb satellite weighs 147 kg and is equipped with a Ku-band antenna. The satellites were manufactured at the OneWeb facility on Merritt Island, Florida, where they are produced in collaboration with Airbus Defense and Space. At this facility, OneWeb currently produces approximately two satellites per day, allowing a theoretical maximum of approximately two launches per month.
Several weeks before launch, 34 satellites were shipped to Kazakhstan where they were integrated into the payload distributor, which was Manufactured by RUAG Space. Then the payload stack was moved to Arianespace The Starsem is integrated with the missile.
Although the Soyuz is a Russian-made missile, RoscosmosArianespace and Starsem handle the commercial sale and vehicle launch for OneWeb assignments.
Four days prior to launch, on August 15, Arianespace conducted a Launch Readiness Review (LRR) to ensure that the launch vehicle and payload are ready for operation and that the ground service equipment (GSE) and launch pad are ready to receive the Soyuz.
A day later, the car rushed to the launch pad, and the GSE was connected. This process involved refueling quick disconnects, shutting down the actuator panel service panel, performing first, second and third stage GSE checks, and making sure the payload was intact.
Two days before the first launch attempt, the teams conducted health checks for the fourth stage of the teams, which had been refueled about two weeks prior.
The countdown began 5 hours 10 minutes before takeoff. Forty minutes later, at T-4 hours and 30 minutes, Soyuz began to refuel RP-1 kerosene and liquid oxygen.
In the T-35 minute, the service gantry shell was lowered to the launch position. Towards the end of the final count, two maintenance arms were pulled away from the Soyuz, followed in T-16 seconds with an order to ignite the rocket’s four RD-107A engines, one on each booster, and the RD-108A central engine.
The four side reinforcements, known as the first stage, burned for 118 seconds and then separated in a pattern known as the Korolev’s cross.
The core, known as the second stage, continued to burn up to T+4 min 48 sec.
The payload structure, which protects the satellites from aerodynamic and thermodynamic loads during ascent, was abandoned at T + 3 min 38 sec.
The third stage implemented a «hot fire» separation from the second stage, meaning that its single engine RD-0124 ignited while the stages were still connected. The third stage then burned for more than four minutes.
(Video comment: How Soyuz rockets light up their engines. Credit: Scott Manley)
The RUAG Space-design payload distributor will then deploy 34 satellites over a period of several hours. Between satellite separation events, Fregat will make position corrections, ensuring that payloads are deployed in the correct position.
The nominal task duration for OneWeb 9 is 3 hours and 45 minutes.
OneWeb satellites will spend the coming months raising their orbits using their Hall-effect engines to reach their final orbit of 1,200 km.
After the final deployment, the Fregat stage will perform a deorbit burn, ensuring the stage is safely returned to Earth’s atmosphere.
(TOP PHOTO: The Soyuz team performs its own program of rolling and swinging after takeoff. Credit: Roscosmos)