Spaceflight Insider

Arianespace to launch two Intelsat communications satellites into orbit

Ariane 5 during its transfer from the Spaceport’s Launcher Integration Building to the Final Assembly Building on Aug. 3.

The Ariane 5 during its transfer from the Spaceport’s Launcher Integration Building to the Final Assembly Building on Aug. 3. Photo Credit: Arianespace

Arianespace is in the final stage of preparations to conduct its sixth mission of the year by launching two Intelsat communications satellites into orbit on Wednesday, Aug. 24. The spacecraft, designated Intelsat 33e and Intelsat 36, will take to the skies from the Ariane Launch Complex No. 3 (ELA 3) in Kourou, French Guiana, atop an Ariane 5 booster. The launch window starts at 5:55 p.m. EDT (21:55 GMT) and extends for 45 minutes.

The launch campaign started in mid-July with the arrival of the satellites in French Guiana. Intelsat 33e was shipped to the Guiana Space Center on July 21, while Intelsat 36 arrived at the center four days later.

Intelsat 33e receives its propellant load during activity in the Spaceport’s S5 payload preparation building. Photo Credit: Arianespace

Intelsat 33e receives its propellant load during activity in the Spaceport’s S5 payload preparation building. Photo Credit: Arianespace

After the arrival, the teams began preparing the satellites for the launch, starting with fit-checks and fueling operations in late July. Both spacecraft were put through a series of tests to ensure all systems are in perfect working order. These tests included electrical checks verifying command and telemetry systems, as well as electrical propulsion tests, validating the Xenon propulsion system. The engineers also performed bi-propellant tests to make sure that each thruster responds correctly to activation commands, to check the valve, and to prove there were no leaks.

On Aug. 6, the Intelsat 33e satellite was mated with the payload adapter in the S5 payload facility and four days later it was encapsulated in the payload fairing. Intelsat 36 was installed on the payload adapter on Aug. 10 and its encapsulation took place on Aug. 13. Three days after that, the stack was placed atop the Ariane 5 launcher.

The launch rehearsal was conducted on Aug. 18. It was followed by final preparations of the booster for the upcoming liftoff. The launch readiness review took place on Aug. 22, while the rollout of the rocket to the launch pad is scheduled to be performed one day before the planned blastoff.

The final countdown for the liftoff will be commenced 11 and a half hours ahead of the launch.

The mission, designated VA232 in Arianespace’s numbering system, will see the Ariane 5 rocket fly for about 42 minutes. During the flight, Intelsat 33e will be released into orbit first, nearly 29 minutes after launch, while Intelsat 36 will separate 13 minutes later.

Built by Boeing, Intelsat 33e is based on the company’s Boeing-702 MP platform. The satellite weighs 6.6 metric tons and measures 26 by 12.5 by 10.5 feet (7.9 by 3.8 by 3.2 meters). It features two deployable solar wings, each with four panels of ultra-triple-junction gallium arsenide solar cells, capable of generating up to 13 kilowatts of power. Its designed lifetime is more than 15 years.

Equipped with 20 C-band and 249 Ku-band transponders, Intelsat 33e will be inserted into a geosynchronous orbit inclined 60 degrees East, replacing Intelsat 904. The satellite is designed to deliver carrier-grade telecom, enterprise networks, aeronautical connectivity, and certain media services. Intelsat 33e is the second spacecraft in the company’s EpicNG series – a high-performance, next-generation satellite platform that delivers global high-throughput technology without sacrificing user control of service elements and hardware.

Its Ku-band spot beams are to provide broadband services for Europe, Africa, the Middle East, and Asia, while a Ku-band wide beam provides broadcast coverage of Europe, the Middle East, and Asia. The satellite’s C-band spot beams will cover high traffic telecommunications centers in Europe, Central Africa, the Middle East, Asia, and Australia. When it comes to the C-band wide beam, it is expected to deliver coverage over sub-Saharan Africa for data and media services.

Intelsat 36 is “topped off” with its onboard propellant. Photo Credit: Arianespace

Intelsat 36 is “topped off” with its onboard propellant. Photo Credit: Arianespace

“This mission is a critical element of our 2016 plan,” Intelsat Investor Relations Vice President Dianne J. VanBeber told SpaceFlight Insider. “We take the next step in establishing our Intelsat EpicNG high-throughput platform, with Intelsat 33e, the second in our series of seven planned satellites. We also launch Intelsat 36, which is a fully committed custom payload for an important DTH customer in South Africa,”

Intelsat 36 was manufactured by Space Systems/Loral (SSL) and is based on the SSL-1300 bus. Weighing about 3.25 metric tons, its dimensions are 17 by 10 by 11 feet (5.2 by 3.1 by 3.4 meters). The spacecraft has two deployable solar arrays that will generate up to 15.8 kilowatts of power. This satellite is also expected to be operational for more than 15 years.

Intelsat 36 is fitted with 34 Ku-band transponders and 10 C-band transponders. Its Ku-band payload will support Intelsat’s MultiChoice direct-to-home service in South Africa, while the C-band payload is expected to provide in-orbit resilience for the video content distribution neighborhood at 68.5 degrees East where the satellite will be co-located in a geosynchronous orbit, together with Intelsat 20.

The Ariane 5 in ECA configuration to be used in Wednesday’s launch is the heavy-lift rocket for missions to geostationary transfer orbit (GTO) and usually carries two telecommunications satellite payloads.

The flight is powered during the initial flight phase by a cryogenic core stage and two solid rocket boosters, followed by the use of a cryogenic upper stage for orbital injection of the payload.

The 180-foot (54.8-meter) tall ECA is an improved version of the Ariane 5 launcher, designed to deliver payloads, mainly communications satellites, weighing up to 10 metric tons.

“We are launching with the most experienced, and most successful, launcher in the business,” VanBeber said. “The launch manifest is very busy, and we were confident that our launch partner, Arianespace, could launch our important birds on time and with the quality that we demand.”

Although it has the same general architecture, some significant changes were made to the basic structure of the generic version to increase thrust and enable it to carry heavier payloads. ECA is also used by institutional customers for non-GTO missions; for example, launching ESA’s Herschel and Planck scientific missions in 2008.

Wednesday’s mission will be the 232nd liftoff of an Ariane vehicle from the Kourou Spaceport. It will be the fourth Ariane 5 launch of 2016 (the 87th Ariane 5 launch overall) and the sixth of 12 flights planned this year by Arianespace, utilizing its family of the heavy-lift Ariane 5, the medium-lift Soyuz, and the lightweight Vega.

Arianespace’s next launch is scheduled for Sept. 16 when it is expected to send into orbit PeruSat 1 for the Peruvian Armed Forces and four SkySat Earth-observing microsatellites for Skybox Imaging. The mission will be performed by the Vega launcher, lifting off from Kourou.


Tomasz Nowakowski is the owner of Astro Watch, one of the premier astronomy and science-related blogs on the internet. Nowakowski reached out to SpaceFlight Insider in an effort to have the two space-related websites collaborate. Nowakowski's generous offer was gratefully received with the two organizations now working to better relay important developments as they pertain to space exploration.

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