Thursday, December 22, 2016

Ariane 5 Launches with Star One D1, JCSAT-15 Satellites

Liftoff of an Arianespace Ariane 5 rocket on mission VA 234. Photo Credit: Jeremy Beck / SpaceFlight Insider

Arianespace has successfully launched one of its flagship Ariane 5 heavy-lift rockets carrying a dual payload for Brazil and Japan. The launch vehicle, with the Star One D1 and JCSAT-15 communication satellites, took to the skies at 5:30 p.m. local time (20:30 GMT / 3:30 p.m. EST) on Dec. 21 from the ELA-3 launch complex at the Guiana Space Center in Kourou, French Guiana.

The launch of Wednesday’s mission, designated VA234, was conducted after a nearly 12-hour countdown, during which last checks of the systems and propellant loading operations were carried out. The countdown culminated with the start of the synchronized sequence that switched the launch vehicle to the onboard power mode and led to the ignition of the rocket’s cryogenic main stage (EPC) and its two solid rocket boosters (EAPs).

The liftoff ended an almost two-month long launch campaign which commenced with the arrival of the JCSAT-15 satellite in Kourou on Oct. 28. Star One D1 arrived at the Guiana Space Center two weeks later, on Nov. 14, when fit-checks and initial tests of the JCSAT-15 spacecraft were already completed and the launch vehicle was taking shape as EAPs were attached to the main stage.

Next, in mid-December, the satellites were integrated, encapsulated in the payload fairing, and finally installed onto the launch vehicle. The launch rehearsal was completed on Dec. 17 and the rocket was rolled out to the launch pad on Dec. 20.

The launch itself went as planned, starting with the ignition of EPC at T–0, which was followed by the ignition of the solid rocket booster duo seven seconds later. The rocket thundered off the launch pad to complete a short vertical ascent lasting about six seconds. After this brief vertical climb, the launcher performed its pitch and roll maneuver, then turned easterly over the Atlantic Ocean.

The boosters powered the launch vehicle for the initial phase of the flight until they were jettisoned at T+2:22 minutes. Next, the main stage continued the mission firing its Vulcain 2 engine for approximately six-and-a-half minutes when this stage separated at T+8:59 minutes. Meanwhile, the protective payload fairing was detached some three minutes and 15 seconds after launch, unveiling the duo of satellites.

Ariane 5’s cryogenic upper stage, known as ESC-A, was ignited nine minutes and three seconds after liftoff and took control over the mission for the rest of the flight. Being powered by its one HM-7B engine, the upper stage continued to accelerate the spacecraft for about 16 minutes until the sole motor burned out its propellant.

ESC-A reached the desired orbit at T+25:23 minutes and began its cruise to deploy the mission’s passengers. Star One D1 was released first at 29 minutes and 10 seconds into the flight, which was followed by the detachment of the SYLDA adapter nearly three minutes later and finally the JCSAT-15 satellite separated at T+43:26 minutes.

However, the VA234 mission ended about half an hour later as the upper stage had yet to conduct final spin-up and avoidance maneuvers. The passivation of this stage was completed one hour and 15 minutes after launch, which concluded the mission.

Built by Space Systems Loral (SSL), Star One D1 is a multi-mission communications satellite based on SSL’s 1300 platform. It has a mass of 6.4 metric tons and its dimensions are 16.7 ft × 7.2 ft × 7.7 ft (5.1 m × 2.2 m × 2.35 m). The satellite features two deployable solar arrays generating up to 17.1 kW of power. It is expected to be operational for more than 15 years.

Star One D1 will be operated by Embratel Star One – a Brazilian communication satellite company. The spacecraft is equipped with 70 transponders, 18 of them in Ka-, 28 in C-, and 24 in Ku-band, and will serve multiple missions including telecommunications, television broadcast, broadband, cellular backhaul, and other services such as digital inclusion in Brazil and in the Latin American region.

“C Band ensures the provisioning of voice signals, TV, radio, and data, including Internet. Ku Band allows video transmission services directly to the users, besides Internet, data and telephony to remote locations. By its turn, Ka Band enables the access to lower-cost broadband and high-speed data transmission for corporate networks and cellular backhaul,” Embratel Star One wrote on its website.

To deliver its services, the satellite will be located at 84 degrees West longitude. This position will allow it to extend the operation of the company’s Brasilsat B4 satellite on C-Band, besides bringing new capacities in Ku (covering Latin America) and Ka (covering Brazil) bands.

Star One D1 is first satellite of the fourth generation of Embratel Star One’s fleet of communications spacecraft. The company’s previous satellite, named Star One C4, was launched into space in July 2015, also atop Ariane 5 from Kourou.

JCSAT-15 was also built by SSL and is based on the 1300 bus. It weighs about 3.4 metric tons and has dimensions of 17 ft × 10.8 ft × 9.8 ft (5.2 m × 3.3 m × 3 m). The satellite is fitted with two power-generating solar panels, providing 10 kW of power; its designed lifetime is more than 15 years.

JCSAT-15 will be operated by SKY Perfect JSAT Corporation – a Japanese satellite communication and multi-channel pay TV company. Equipped with Ku-band transponders, the spacecraft will be used to help broadcast the multichannel pay TV service in Japan, and it will also provide data transfer communications and maritime and aviation applications for the Oceania and Indian Ocean Region.

“JCSAT-15 will allow SKY Perfect JSAT to contribute to the new era of TV broadcasting by offering Ultra HD or 4K programming. In addition, its expanded coverage will help us to fulfill the growing demand for mobile connections,” said Shinji Takada, Representative Director, president and CEO of SKY Perfect JSAT.

“SKY Perfect JSAT and SSL have developed a close working relationship based on our shared commitment to quality, service, and making the world a better place,” said John Celli, president of SSL.

The new satellite will replace the company’s N-SAT-110 spacecraft, currently located at 110 degrees East longitude. The previous spacecraft in the series, JCSAT-16, was orbited in August 2016 by SpaceX’s Falcon 9 launcher lifting off from Cape Canaveral, Florida.

The Ariane 5 in ECA configuration that was employed for Wednesday’s launch is the heavy-lift rocket Arianespace uses 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 communication 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 Arianespace’s 11th launch of the year and the seventh Ariane 5 flight from Kourou in 2016. The satellites are the 60th and 61st SSL spacecraft launched by Arianespace to date.

Arianespace’s next launch is scheduled for Jan. 28, when it is expected to send into orbit the Hispasat AG1 communications satellite for the Spanish company Hispasat. The mission will be performed by the Soyuz ST-B launcher, lifting off from Kourou.

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