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Image Credit: ESA-S Corvaja.

Ariane 5 to launch two commercial geostationary satellites

An Arianespace Ariane 5 heavy-lift rocket is scheduled to blast off from the Guiana Space Centre in French Guiana on Friday, July 30, 2021 between 21:00 UTC and 22:30 UTC. The launch vehicle will carry the two commercial geostationary satellites Star One D2 of Embratel and Eutelsat Quantum of Eutelsat, into a geostationary transfer orbit. The mission will be Arianespace’s sixth rocket launch of 2021 and this year’s first Ariane 5 mission.

Mission profile

Once the countdown clock hits zero, the liquid-fueled Vulcain 2 rocket engine on Ariane 5’s first stage will ignite and the rocket’s onboard computer will conduct a final systems test of the engine ahead of liftoff. If everything remains “Go” for launch, the two large solid rocket boosters (SRB) will ignite at T+7 s and the Ariane 5 rocket will blast off from the Guiana Space Centre in French Guiana.

After about 143 s of flight, the two 31.6 m tall SRBs will burn out and will be separated from the EPC core stage.

Once Ariane 5 reaches space, the payload fairing will be jettisoned, exposing the two satellites to the vacuum of space. This milestone is scheduled to occur about 191 seconds after launch.

At around T+9 min, the Vulcain 2 is expected to shut down and the core stage will separate from the ECS-D second stage. This will be followed by the ignition of the liquid-fueled HM-7B second stage engine shortly afterwards.

~16 minutes later, the upper stage will shut down, completing the powered phase of flight. A few minutes after engine cut off, the upper passenger, Star One D2, will be separated from the Ariane 5. Before Eutelsat Quantum can be separated from the rocket, the Sylda, a support structure between the two spacecraft, will be deployed. The total flight time from liftoff until the separation of the second passenger will be 36 minutes, 24 seconds.

The Ariane 5 launch vehicle will only insert the two satellites into a geostationary transfer orbit, 250 km x 35,726 km in altitude and inclined by 3 degrees. Once Eutelsat Quantum and Star One 2D will reach their apogees, the two spacecraft will ignite their own onboard propulsion system, circularizing their orbits.

The Star One D2 satellite

Star One D2 is a Maxar built 6,190 kg heavy telecommunications satellite operated by STAR ONE S.A, a subsidiary of the Brazilian satellite operator Embratel. The spacecraft is based on Maxar’s 1300-class satellite platform and is equipped with Ku-, Ka- and C-band transponders to provide broadband coverage and internet access to rural and previously uncovered regions in Central and South America. The satellite also hosts an X-band payload for government use over the Atlantic region.

The Eutelsat Quantum Satellite

Eutelsat Quantum is an Airbus Defence and Space built 3,461 kg heavy spacecraft developed by the European Space Agency (ESA), Eutelsat and Airbus. The satellite is operated by Eutelsat and will be stationed in a geostationary Earth orbit at 48 degrees East over the equator. The spacecraft is equipped with an electronically steerable receiving antenna and eight independent reconfigurable Ku-band beams. This will enable users to actively define and shape Eutelsat Quantum’s performance for their specific purposes.

The Ariane 5 launch vehicle

The Ariane 5 is a two-stage, heavy-lift launch vehicle operated by Arianespace. The vehicle is up to 57.72 m in length, 11.50 m in diameter and has a launch mass of 775 tonnes. The rocket is composed of the 31 m tall EPC core stage with its single Vulcain 2 engine, two large solid rocket boosters attached to the EPC, a 4.71 m tall and 19 tonnes heavy cryogenic second stage and a up to 20 m high payload fairing. The equipment bay with the rocket’s onboard computer is located atop the ESC-D upper stage.

The maiden flight of the rocket occurred on June 4, 1996 and the Ariane 5 has since flown over 100 times. Europe’s workhorse mainly launches heavy geostationary satellites into orbit, but has previously also flown several space probes like Rosetta and BepiColombo into deep space, as well as the uncrewed ATV resupply freighters to the International Space Station (ISS). Later this year, an Ariane 5 is scheduled to launch the James Webb Space Telescope (JWST), the successor to the legendary Hubble Space Telescope, into space.

An Ariane 5 blasts off from French Guiana. Image Credit:  ESA–Stephane Corvaja, 2016.
An Ariane 5 blasts off from French Guiana. Image Credit: ESA–Stephane Corvaja, 2016.


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