It was last launch in 2016 for Arianespace. Today, at 20:30 UTC, Ariane 5 was launched at the begining of 75 minute launch window to deliver to orbit two satellites: JCSAT-15 and Star One-D1.
This is another mission of two satellites made by SSL and launched under the fairing of Ariane 5 (first was VA 230 flight performed on June 18 with EchoStar-18 and BRIsat). Star One-D1 satellite is operated by Star One, Brazilian communication satellite company, a subsidiary of Embratel. Star One-D1 represents fourth generation of satellites belonging to Star One. It was built using SSL-1300 satellite bus; it weighs 6340 kg and is able to operate for at least 15 years at GEO 84° W orbital slot. Two deployable solar arrays and onboard batteries will power 70 Ka, C and Ku band transponders covering with range Brazil, Latin America, Central America, Mexico and the Caribbean.
JCSAT-15 is 18th communication satellite operated by SKY Perfect JSAT Corporation, one of the leading companies communication and multi-channel pay TV market in Asia. Satellite is also based on SSL-1300 and will operate on 110° East GEO orbital slot. It will replace JCSat-110 satellite remaining in service since 2000. JCSAT-15 weighs 3400 kg and is powered by two deployable solar arrays. Satellite will help in providing SKY PerfecTV! service in Japan, but also will improve data transfer, maritime and aeronautical services for Oceania and Indian Ocean regions.
Launch preparations started on 19 December 2016, when rocket was rolled out from assembly facility and moved to ELA-3 launch pad. Eleven hours before launch final countdown started (at T-11h43'). It was followed by general inspection of electrical systems 70 minutes later. Procedure of fueling first stage started at T-4h23" and of second cryogenic stage - at T-3h43'. Rocket was ready to begin its mission covering delivering 10722 kg of payload to orbit with perigee at 250 km, apogee at 35905 km and inclination at 6°. At T-7' synchronized sequence has started; one minute later flight levels inside propellant tanks were confirmed. At T-4 pressurization process has started and after receiving favorable weather forecast, pyrotechnic charges were armed. At T-3' valves were open and LOX started to chill engines. Punctually at 20:30 UTC rocket lifted off. Ariane 5 ECA configuration is based on two solid rocket boosters (EAB); each one is long for 36 m with diameter at 3.05 m, what makes them longer compared to first stage of the rocket long for 30.5 m (with diameter at 5.4 m). During first minute of flight boosters and first stage were providing over 7000 kN of thrust. Boosters were separated after one minute of flight at T+2'20"; at T+3'30 nose cone was jettisoned on altitude of 110 km, when rocket reached already speed of 8 Ma. At T+9'15" Vulcain -2 engine was cut off and stopped providing 1390 kN of thrust. Next, first stage was jettisoned and upper stage ignited its HM7B engine fueled with liquid oxygen and hydrogen. At the same time rocket entered into zone, when it was tracked by Ascension Island tracking station. Second stage weighing 4540 kg and long for 5.4 m (with diameter at 4.7 m) begun its autonomous flight. Two minutes later rocket reached altitude of 150 km and speed of around 24000 km/h. At T+21' rocket begun to be tracked by Libreville tracking station in Gabon. It was followed by entering into range of Malindi tracking station in Kenya three minutes later. At T+25'30" upper stage switched off its engine and four minutes later Star One-D1 was deployed from Sylda payload adapter. Next, rocket was continuing ballistic flight to release adapter and expose JCSAT-15 at T+31'58". Finally JCSAT-15 was deployed at T+45'. At 21:25 UTC JCSAT-15 and Star One-D1 confirmed its good condition.