Astronomy and Space News - Astro Watch: Ariane 5 Successfully Lofts Two Communications Satellites for Intelsat


Thursday, August 25, 2016

Ariane 5 Successfully Lofts Two Communications Satellites for Intelsat

Ariane 5 rocket lifts off with two Intelsat satellites on Aug. 24. Credit: Arianespace

Thundering off the launch pad at Kourou in French Guiana, an Ariane 5 booster took to the skies on Wednesday, Aug 24, to deliver Intelsat 33e and Intelsat 36 commsats into orbit. The mission, designated VA232 in Arianespace’s numbering system, lifted off at 5:55 p.m. EDT (21:55 GMT) from the Ariane Launch Complex No. 3 (ELA 3).

Countdown for the launch started 11 and a half hours before the planned liftoff, allowing the teams to conduct final checks of electrical systems. Next, the launch vehicle was filled with liquid oxygen and hydrogen what paved the way for the inspection of connections between launcher and the telemetry, tracking and command systems, about one hour ahead of the launch. All the systems was cleared for the blastoff and a synchronized sequence commenced at T-7 minutes, managed by the control station and onboard computers, leading to ignition of the rocket’s main stage engine and its two boosters.

When the two boosters were ignited about seven seconds after the main stage engine started its work, Ariane 5 began its short vertical climb. About half a minute later, after completing the pitch and roll maneuver, the rocket started flying East, towards the Atlantic Ocean. The boosters, powering the launch vehicle in this initial phase of the flight, were jettisoned two minutes and 22 seconds after liftoff.

Afterwards, the rocket, being accelerated by the main stage alone, flew for about six and a half minutes, until it separated from the launch vehicle. During this phase of the flight, payload fairing was jettisoned, unveiling the mission’s two passengers.

The upper stage was ignited about four seconds after the first stage was detached and took control over the flight, burning its engine for nearly 16 minutes until it was cut off. Then, at T+25 minutes and 13 seconds, the launched vehicle was injected into the targeted orbit, releasing the Intelsat 33e about three and a half minutes later. Intelsat 36 was deployed 41 minutes and 50 seconds after launch.

The successful deployment of both spacecraft ends a busy month-long launch campaign that started in the second half of July, with arrival of the satellites at Kourou. The teams worked around the clock to fully prepare the launch vehicle and its passengers for Wednesday’s flight, starting with fit-checks and fueling operations in late July. 

“We wanted to get both satellites in orbit and operational safely and on time. Placing both satellites on this Ariane 5 vehicle, the most reliable launcher in the business, is our best opportunity to ensure that will happen,” Intelsat Media Communications Manager Jason Bates told

The satellites were mated with the payload adapter and encapsulated in the payload fairing in the first half of August. The stack was placed atop the Ariane 5 launcher on Aug. 16 and two days later the launch rehearsal was conducted. The launch readiness review took place on Aug. 22, while the rollout of the rocket to the launch pad was performed one day before the planned liftoff.

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 33e is the second of our high throughput Intelsat EpicNG satellites and will provide next-generation services throughout Africa, the Middle East, Europe and Asia,” Bates noted. “The higher performance and improved economics delivered by Intelsat EpicNG are ideal to meet the growing infrastructure needs of broadband providers trying to connect populations in developing regions. Our approach to high-throughput services enables them to take full advantage of our open architecture, backward compatible platform; the combination of wide and spot beams; and lower total cost of ownership that we deliver to expand connectivity.”

Intelsat 33e joins the first Intelsat EpicNG satellite, Intelsat 29e, which serves the Americas and the busy North Atlantic travel route, to provide high-throughput satellite coverage of the vast majority of the Earth’s populated regions and enable the expansion of existing applications and the development of new services. 

Bates revealed that when the Horizons 3e satellite, jointly owned by Intelsat and JSAT, is launched in 2018 to cover the Asia-Pacific region, his company will have complete global coverage with the Intelsat EpicNG platform, providing high-performance capacity for service providers delivering broadband connectivity to ships and aircraft traveling around the globe.

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 (DTH) 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.

“Intelsat 36 is a media satellite that will support our long-standing customer, Multichoice, Africa’s leading pay-TV provider. MultiChoice provides pay-TV and subscriber management services in 49 countries across sub-Sahara Africa and the Indian Ocean islands, and under a 15-year service agreement, Intelsat 36 will enable MultiChoice to expand its DTH services to meet the growing demand for entertainment and education options and the distribution of locally produced content within Africa,” Bates said.

He added that Intelsat 36 is going to dramatically expand the amount of high definition video available to the Sub-Saharan region.

“Both satellites are very different. Intelsat 33e is designed for broadband applications for Europe, Africa and Asia, for enterprise, wireless, mobility and government customers, while Intelsat 36 is optimized for media distribution in the South Africa and South Asia regions,” Intelsat Investor Relations Vice President Dianne J. VanBeber told SpaceFlight Insider.

The Ariane 5 in ECA configuration that was 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.

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 was the 232nd liftoff of an Ariane vehicle from the Kourou Spaceport. It was 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.

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