Spaceflight Insider

Ariane 5 deploys 2 communications satellites

An Ariane 5 rocket rises skyward to send two communications satellites into geostationary orbit. Photo Credit: Arianespace

An Ariane 5 rocket rises skyward to send two communications satellites into geostationary orbit. Photo Credit: Arianespace

In the first of a dozen or so missions for Arianespace in 2019, an Ariane 5 rocket sent two communication satellites into a geostationary transfer orbit.

Lifting off at 4:01 p.m. EST (21:01 GMT) Feb. 5, 2019, from French Guiana in South America, the rocket leapt into rainy and clouding skies. However, the vehicle is designed to launch in a little bit of rain.

Sent into orbit were two satellites: Saudi Geostationary Satellite 1/Hellas Sat 4 for Saudi Arabia and Greece and GSAT-31 for the Indian Space Research Organisation. They are expected to ultimately reside in geostationary orbit to provide broadband coverage to Saudi Arabia, Europe and the Middle East; and “bridge the digital divide in the Indian subcontinent,” respectively.

Saudi Geostationary Satellite 1/Hellas Sat 4, inside the payload fairing in the background, is being readied to be placed over the GSAT-31 co-passenger in advance of launch. Photo Credit: Arianespace

Saudi Geostationary Satellite 1/Hellas Sat 4, inside the payload fairing in the background, is being readied to be placed over the GSAT-31 co-passenger in advance of launch. Photo Credit: Arianespace

“With this first launch of the year, we celebrate Ariane’s 40th birthday,” said Arianespace CEO Stephane Israel during a post-launch briefing. 

The first Ariane rocket, and Ariane 1, was launched on Dec. 24, 1979. That test launch was a success and deployed the first satellite launched by the European Space Agency on its own rocket.

“Ariane 5 reasserts tonight its leading position on the geostationary market,” Israel said. “Indeed, tonight’s launch has started a series of up to five Ariane 5 ECA dual launches in 2019. They will be all dedicated to global commercial customers in dual launches.”

For this mission, dubbed VA247, once the countdown reached zero, the core stage’s Vulcain 2 main engine ignited and spun up to full power. Once the onboard computer verified the engine was performing as expected, it commanded the twin solid rocket boosters to ignite—about 7 seconds after main engine ignition—sending the vehicle hurtling off the pad.

While not a particularly tall rocket at just over 165 feet (51.1 meters) in height, the Ariane 5 packs a punch, producing well over 3 million pounds of thrust at liftoff.

After liftoff, the vehicle headed straight up for about 10 seconds before the roll program automatically executed, pitching the vehicle over and sending the rocket, while still climbing skyward, away from the launch site and toward its designated orbit.

The rocket achieved Mach 1, or about 717 mph (1,195 kph) at about 49 seconds into the mission, just 42 seconds after leaving the launch pad. Ariane 5 passed through the area of maximum dynamic pressure, where the air creates the most force of the rocket at 1 minute, 8 seconds and then continued its rapid acceleration toward orbit.

The two solid rocket boosters burned out at about 2 minutes, 22 seconds and fell away to crash into the ocean. At that time, the vehicle already at over 41 miles (66 kilometers) in altitude.

Meanwhile, the core stage’s single Vulcain 2 main engine continued to power the vehicle.

The Ariane 5 rocket with the Saudi Geostationary Satellite 1/Hellas Sat 4 and GSAT-31 satellites encapsulated stands at the launch pad in advance of its liftoff. Photo Credit: Arianespace

The Ariane 5 rocket with the Saudi Geostationary Satellite 1/Hellas Sat 4 and GSAT-31 satellites encapsulated stands at the launch pad in advance of its liftoff. Photo Credit: Arianespace

About 3 minutes, 21 seconds into the flight, while the vehicle was at an altitude of nearly 68 miles (109 kilometers) where the atmosphere was so thin it posed no danger to its payload, the payload fairing was jettisoned.

The core stage burned for another 5 minutes, 30 seconds before it shutdown, having exhausted its supply of fuel with stage separation occurring just 6 seconds later.

The expendable core stage was then put in a flat spin mode by opening a lateral venting hole in the hydrogen tank which would cause it to re-enter the atmosphere.

From there it was the job of the second stage’s single engine to put the payloads into their proper geostationary transfer orbits.

The Saudi Geostationary Satellite 1/Hellas Sat 4 spacecraft was released first some 27 minutes after liftoff. The Indian Space Research Organisation’s GSAT-31 released second at about 42 minutes after launch.

This was the first launch of 2019 for Arianespace and the 103rd overall Ariane 5 flight. The company’s next mission is anticipated for Feb. 19, when a Soyuz rocket is expected to send the first 10 satellites into orbit for OneWeb, a company developing a low-latency broadband communications constellation.

Video courtesy of Arianespace

 

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Lloyd Campbell’s first interest in space began when he was a very young boy in the 1960s with NASA’s Gemini and Apollo programs. That passion continued in the early 1970s with our continued exploration of our Moon, and was renewed by the Shuttle Program. Having attended the launch of Space Shuttle Discovery on its final two missions, STS-131, and STS-133, he began to do more social networking on space and that developed into writing more in-depth articles. Since then he’s attended the launch of the Mars Science Laboratory Curiosity rover, the agency’s new crew-rated Orion spacecraft on Exploration Flight Test 1, and multiple other uncrewed launches. In addition to writing, Lloyd has also been doing more photography of launches and aviation. He enjoys all aspects of space exploration, both human, and robotic, but his primary passions lie with human exploration and the vehicles, rockets, and other technologies that allow humanity to explore space.

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