Measat, Optus get a boost from 75th Ariane 5 launch
BY STEPHEN CLARK
Posted: September 11, 2014
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.
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.
Once the problem was cleared, the countdown resumed under a computer-controlled synchronized sequence. The Ariane 5 pressurized 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 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.
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 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."
Outfitted with 48 Ku-band transponders, Measat 3b will expand direct-to-home television services in Malaysia, Indonesia, India and Australia, serving more than 18 million households, according to Measat.
The Optus 10 satellite launched by the Ariane 5 rocket is heading for geostationary orbit to support direct television broadcasts, Internet, telephone and data transmission services to Australia, New Zealand and the Antarctic region.
Launched for the Australian communications firm Optus, the satellite 7,209-pound (3,270-kilogram) spacecraft hosts 24 Ku-band transponders, according to Space Systems/Loral of Palo Alto, Calif., Optus 10's manufacturer.
The flight plan called for Optus 10 to unfurl its solar arrays and begin a series of four maneuvers to circularize its orbit at geostationary altitude. After 20 days of payload testing, the satellite should begin service in October.
Optus 10 is heading for a geostationary slot at 164 degrees east longitude.
Next up for Arianespace is another Ariane 5 launch set for Oct. 16 with the Intelsat DirecTV Latin America 1 satellite and the Arsat 1 payload, the first large communications spacecraft built in Argentina.
Follow Stephen Clark on Twitter: @StephenClark1.