Ariane 5 ECA launches with the giant TerreStar-1 satellite

by Chris Bergin

Arianespace were back in action on Wednesday, with the launch of their Ariane 5 ECA and a single passenger, the TerreStar-1 communications satellite. Launch from the European Spaceport in French Guiana was delayed by a storm that passed over the center, and several technical issues, before launching at 17:52 GMT.

This mission is Arianespace’s third of seven Ariane 5 flights planned in 2009, marking the 189th flight of an Ariane family vehicle, and the 45th launch for Ariane 5.

Wednesday’s launch follows the year-opening flight on February 12 that orbited Eutelsat’s HOT BIRD 10 and NSS-9 for SES NEW SKIES, along with two Spirale auxiliary passengers for the French military; and the May 14 launch with the European Space Agency’s Herschel and Planck deep space telescopes.

Click here to review previous Ariane 5 launches: http://www.nasaspaceflight.com/?s=Ariane

With a lift-off weight of nearly 6,910 kg., TerreStar-1 rode as a single passenger on the dedicated Ariane 5.

Overview:

This Space Systems/Loral-built spacecraft will operate in the 2 GHz spectrum, enabling the American telecommunications operator TerreStar Networks to provide voice, data and video communications to satellite/terrestrial mobile devices the size of a typical smart phone.

The launcher’s attitude and trajectory are totally controlled by the two onboard computers, located in the Ariane 5 vehicle equipment bay (VEB). 7.05 seconds after ignition of the main stage cryogenic engine at T-0, the two solid-propellant boosters are ignited, enabling lift-off.

The launcher first climbs vertically for 6 seconds, then rotates towards the East. It maintains an attitude that ensures the axis of the launcher remains parallel to its velocity vector, in order to minimize aerodynamic loads throughout the entire atmospheric phase, until the solid boosters are jettisoned.

Once this first part of the flight is completed, the onboard computers optimize the trajectory in real time, minimizing propellant consumption to bring the launcher first to the intermediate orbit targeted at the end of the main stage propulsion phase, and then the final orbit at the end of the flight of the cryogenic upper stage.

The main stage falls back off the coast of Africa in the Atlantic Ocean (in the Gulf of Guinea). On orbital injection, the launcher will have attained a velocity of approximately 9563 meters/second, and will be at an altitude of about 417 kilometers.

The fairing protecting the TerreStar-1 spacecraft is jettisoned shortly after the boosters are jettisoned at about T+190 seconds.

Spaecraft separation of the TerreStar-1 satellite will occur just over 26 minutes into flight.

TerreStar-1 is equipped with an 18-meter deployable reflector and powerful S-Band feed array, and will be capable of managing some 500 beams during an in-orbit design lifetime of more than 15 years. Its relay services are tailored to provide critical services for government, emergency responders, rural communities and commercial users throughout the United States and Canada.

Built by Space Systems/Loral using the company’s 1300 satellite platform, TerreStar-1 will operate in the 2 GHz spectrum to provide voice, data and video communications to satellite/terrestrial mobile devices the size of a typical smart phone.

Ahead of the launch, TerreStar President Jeffrey W. Epstein noted: “We are looking forward to a successful launch and the new, game-changing mobile satellite services TerreStar-1 will allow us to deliver.”

The spacecraft will be operated by Reston, Virginia-based TerreStar Networks, which plans to offer next-generation mobile communications through a network of partners and service providers for users who need “anywhere” coverage throughout the United States and Canada.

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