Arianespace preps 2 satellites for launch atop workhorse Ariane 5 … – SpaceFlight Insider

Curt Godwin

February 13th, 2017

During final integration at the Spaceport for Flight VA235, Telkom 3S is positioned atop the Ariane 5s core cryogenic stage (photos at left and center), followed by placement of the payload fairing containing SKY Brasil-1 and the SYLDA dispenser system (photo at right). Photo(s) Credit: Arianespace

With its Launch Readiness Review complete, Arianespace continues to make preparations to launch itsfirst Ariane 5 rocket of 2017. The delivery into space of two communication satellites,SKY Brasil-1 and Telkom 3S, is scheduled for the beginning of an 86-minute launch window that opens at 4:39 p.m. EST (21:39 GMT) on Feb. 14, 2017.

Archive photo of Ariane flight VA233. Photo Credit: Stephane Corvaja / ESA

The mission, designated VA235, is being flown todeliver the two satellites to geosynchronous transfer orbit (GTO). The European heavy-lift vehicle is notable in its capability to deliver multiple, large satellites into orbit, allowing customers to share launch costs.

The 13,228-pound (6,000-kilogram) AT&T/DirecTV SKY Brasil-1 spacecraft will supply digital entertainment services to Brazil via DirecTVs Latin America subsidiary.

Sharing the ride to GTO inside the fairing will be the 7,826-pound (3,550-kilogram) Telkom 3S digital services satellite.

The state-owned Telkom Indonesia satellite will provide telecommunications and high-definition television services throughout the island nation.

Riding in the lower bay of the two-position SYLDApayload carrier is the Telkom 3S satellite. The third Telkom satellite to be launched by Arianespace, it was built on the Thales Alenia Space Spacebus 4000B2 platform and is outfitted with 24 C-band, eightextended C-band, and 10 Ku-band transponders.

Telkom 3S will ultimately be positioned at 118 degrees Eastand will provide a multitude of digital services to customers in Indonesia, Malaysia, and Southeast Asia. The medium-class satellite has twin solar arrays, providing the necessary6.3 kilowatts of payload power, and has an expected on-orbit lifetime of 15 years.

The other satellite, SKY Brasil-1, will sit in SYLDAs top position. Alternately known as Intelsat 32e, the satellite was built on the Airbus Defense and Space Eurostar E3000 spacecraft architecture, a widely used and flexible satellite bus.

Using its60 Ku-band transponders, the satellite will provide servicesto Brazil and areas of the North Atlantic Ocean. After settlinginto its orbital slot at 43.1 degrees West, SKY Brasil-1 is expected to deliver digitalcontent for at least 19 years.

Arianespaces reliable Ariane 5 rocketwill be delivering the satellite duoto GTO. It is configured in its ECA arrangement for flight VA235. The heavy-lift rocket has been a mainstay of the multinational launch providerand offers a high degree of precisionwith its ability to place payloads into orbit with near meter-level accuracy.

Like NASAs now-retired Space Shuttle, the Ariane 5 makes use ofsolid-fueled boosters to supplement the mainliquid-fueled engine.

A pair of P241 solid rocket boosters will provide a combined 3.18 million pounds (14,160 kilonewtons) of thrust at liftoff. Each will burn for approximately 130 seconds, providing roughly 92 percent of the Ariane 5s liftoff thrust. Once their propellant is consumed, they will separate and fall into the Atlantic Ocean.

Supplying the remaining eightpercent of liftoff power is the core stages Vulcain 2 cryogenic engine. Burning a mixture of liquid hydrogen and liquid oxygen, the hydrolox powerplant provides 220,000 pounds (960 kilonewtons) of sea-level thrust. That increases to 310,000 pounds (1,390 kilonewtons) as it climbs into the vacuum of space.

The second stage is outfitted with a single HM7B cryogenic engine. Itsupplies 15,000 pounds (67 kilonewtons) of vacuum thrustand can operate for 945 seconds.

The mission will be broadcast live via Arianespaceswebsite. Coverage will begin 15 minutes beforethe scheduled liftoff.

An artists rendering of the SKY Brasil-1 digital television satellite, set to launch aboard an Ariane 5. Image Credit: Arianespace

Tagged: Ariane 5 ArianeSpace Guiana Space Centre Lead Stories Sky Brasil-1 Telkom 3S VA235

Curt Godwin has been a fan of space exploration for as long as he can remember, keeping his eyes to the skies from an early age. Initially majoring in Nuclear Engineering, Curt later decided that computers would be a more interesting - and safer - career field. He's worked in education technology for more than 20 years, and has been published in industry and peer journals, and is a respected authority on wireless network engineering. Throughout this period of his life, he maintained his love for all things space and has written about his experiences at a variety of NASA events, both on his personal blog and as a freelance media representative.