Saturday, September 13, 2014

ESA Ariane 5 Rocket Launches Measat 3b and Optus 10 Satellites Into Orbit

Arianespace successfully launched two telecommunications satellites, Boeing's MEASAT-3b and SSL's OPTUS 10 on Sept. 11, 2014, from Kourou, French Guiana.

Credit: Arianespace

Stacked inside the shroud of an Ariane 5 rocket, two commercial television broadcasting satellites for Malaysian and Australian telecommunications companies blasted off from French Guiana on Thursday.

Boeing's MEASAT-3b
The MEASAT-3b and OPTUS 10 spacecraft rocketed away from a launch pad in Kourou, French Guiana, at 2205 GMT (6:05 p.m. EDT), riding on top of an 18-story Ariane 5 booster to begin 15-year missions to broadcast television programming to millions of customers in the Asia-Pacific.

Liftoff of the Ariane 5 rocket was delayed 44 minutes after a status board at the European-run Guiana Space Center displayed a "red" condition, signaling a problem.

No details of the issue were released during the launch's official webcast.

The countdown was paused twice, including a hold 27 seconds before liftoff before the launch team reset the clock to the 7-minute mark.

Officials said ground teams needed more time to configure a downrange tracking station in Kenya.

SSL's OPTUS 10
Once the problem was cleared, the countdown resumed under a computer-controlled synchronised sequence.

The Ariane 5 pressurised its propellant tanks and ignited its Vulcain 2 main engine when the countdown reached zero.

Seven seconds later, after passing an automated health check, the rocket fired its two solid-fueled boosters and blasted off on top of a column of hot orange exhaust.

The Ariane 5's hydrogen-fueled core engine and twin solid rocket boosters pushed the launcher into a clear sky, passing the speed of sound in 41 seconds as it pitched east over the Atlantic Ocean.

The two boosters burned their pre-packed powder propellant in a little over 2 minutes and fell away from the Ariane 5 rocket to plummet back into the sea 41 miles below.

The Ariane 5's main stage continued firing as it released a nose shroud to expose the mission's dual-payload composite once the rocket flew into the outer reaches of Earth's atmosphere.

The Vulcain 2 main engine gave way to the launcher's upper stage engine 9 minutes after liftoff.

On cue, the rocket's HM7B second stage powerplant switched off after a 16-minute burn to put the MEASAT-3b and OPTUS 10 satellites into an on-target geostationary transfer orbit, an egg-shaped path around Earth used as a waypoint to the craft's final operating positions.

In a three-step deployment procedure, the Ariane 5's upper stage released MEASAT-3b, then ejected a Sylda dual-payload adapter covering OPTUS 10.

Then the rocket separated Optus 10 about at 2239 GMT (6:39 p.m. EDT), prompting smiles and applause to break the tension inside the control room in Kourou.

"Arianespace has just received confirmation from our on-board telemetry systems that MEASAT-3b and Optus 10 were separated as planned," said Stephane Israel, chairman and CEO of Arianespace, the French company which manages Ariane 5 launch operations and sales.

Thursday's flight notched the Ariane 5's 61st consecutive successful launch.

For engineers working on the mission's payloads, the launch was just the beginning.

"It's only the start because the operations are just starting," said Arnaud de Rosnay, executive vice president for telecommunications satellites at EADS Airbus Defence and Space, the manufacturer of MEASAT-3b for the Malaysian telecom company Measat.

"I've just had confirmation that we've received telemetry from the control center in Toulouse, and the early operations of the stellite are working fine."

The 13,000-pound (5,897-kilogram) MEASAT-3b satellite will fire its orbit-raising propulsion system four times in the next five-to-six days to reach a circular orbit approximately 22,300 miles over the equator.

Once there, the spacecraft will extend its power-generating solar panels and antennas to prepare to enter service.

At that altitude, known as geostationary orbit, the satellite will hover over the same location on Earth.

MEASAT-3b should enter service by mid-October parked over the equator at 91.5 degrees east, according to Measat.

"MEASAT's successful procurement and launch of the MEASAT-3b satellite is a great achievement for Measat, for Malaysia's ICT (Information and Communications Technology) infrastructure, and for the Malaysian space industry," said YB Dato' Jailani Johari, Malaysia's deputy minister of communication and multimedia, in a press release.

"We trust that Measat will continue to push the boundaries of both business and technology as they look to become the world's leading emerging market satellite operator."

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