An Ariane 5 rocket will fire into the sky from French Guiana just after sunset Tuesday and deliver two payloads to orbit for Intelsat, one of the world’s largest commercial satellite operators, and Broadcasting Satellite System Corp. of Japan.
The nearly 180-foot-tall (55-meter) launcher will blast off from Kourou, French Guiana, at 2151 GMT (5:51 p.m. EDT; 6:51 p.m. French Guiana time) on its fifth flight of the year with the Intelsat 37e and BSAT 4a communications satellites.
Made in California by Boeing and Space Systems/Loral, respectively, Intelsat 37e and BSAT 4a will ride aboard the Ariane 5 in a dual-payload stack. The larger of the two satellites, Intelsat 37e, will deploy first, followed by separation of BSAT 4a around 47 minutes after liftoff.
The rocket will target an orbit ranging from 155 miles (250 kilometers) to 22,186 miles (35,706 kilometers), with a tilt of 6 degrees to the equator.
Date source: Arianespace
T-0:00:00: Vulcain 2 ignition
The Ariane 5’s first stage Vulcain 2 main engine ignites as the countdown clock hits zero, throttling up to about 300,000 pounds of thrust and undergoing a computer health check before liftoff.
T+0:00:07: Solid rocket booster ignition and liftoff
The Ariane 5’s two solid rocket boosters ignite seven seconds later, each generating more than 1.3 million pounds of thrust, to push the vehicle into the sky from the ELA-3 launch pad.
T+0:00:50: Mach 1
The Ariane 5 rocket surpasses the speed of sound, heading east over the Atlantic Ocean.
T+0:02:19: Solid rocket boosters jettisoned
After each consuming 240 metric tons, or about 530,000 pounds, of pre-packed propellant, the solid rocket boosters are jettisoned.
T+0:03:23: Payload fairing jettisoned
The Ariane 5’s 17.7-foot-diameter (5.4-meter) payload fairing, made in Switzerland by Ruag Space, releases in a clamshell-like fashion once the rocket flies above the denser, lower layers of Earth’s atmosphere.
T+0:08:56: Vulcain 2 shutdown
The Ariane 5’s core stage Vulcain 2 main engine shuts down after consuming 175 metric tons (385,000 pounds) of cryogenic liquid hydrogen and liquid oxygen propellants.
T+0:09:02: Stage separation
The Ariane 5’s first and second stages separate. The 98-foot-long (30-meter) first stage will fall into the Atlantic Ocean near the Gulf of Guinea off the west coast of Africa.
T+0:09:06: HM7B ignition
The Ariane 5’s upper stage HM7B engine ignites for a 16-minute, 25-second burn to place the Intelsat 37e and BSAT 4a satellites into geostationary transfer orbit. The HM7B engine burns liquid hydrogen and liquid oxygen, and generates more than 14,000 pounds of thrust.
T+0:25:31: HM7B shutdown
The HM7B engine shuts down after placing the Intelsat 37e and BSAT 4a satellites into geostationary transfer orbit with a low point of 155 miles (250 kilometers), a high point of 22,186 miles (35,706 kilometers), and an inclination of 6 degrees to the equator.
T+0:29:50: Intelsat 37e separation
TThe Intelsat 37e satellite, riding in the upper position on the Ariane 5’s dual-payload stack, deploys to begin a 15-year mission serving television, broadband and mobile communications markets.
T+0:31:56: Sylda 5 separation
The Sylda 5 dual-payload adapter structure jettisons from the Ariane 5 upper stage, revealing the BSAT 4a spacecraft for deployment.
T+0:47:15: BSAT 4a separation
The BSAT 4a satellite is released from the Ariane 5 upper stage for a mission providing HD and Ultra HD television broadcast services over Japan.
A Falcon 9 launcher bolted into the sky over Florida’s Space Coast on Friday, adding the brilliant orange glare of rocket exhaust to a spectacular sunset as the 229-foot-tall booster propelled the SES 9 communications satellite into orbit to serve the Asia-Pacific with high-definition television programming and connectivity on-the-go.
SpaceX’s final Falcon 9 launch of the year carried a classified payload for the National Reconnaissance Office, the U.S. government’s spy satellite agency. SpaceX aborted a launch attempt Thursday morning to assess a second stage sensor reading, but the Falcon 9 successfully lifted off from the Kennedy Space Center at 9 a.m. EST (1400 GMT) Saturday. The rocket’s stage landed back at Cape Canaveral eight minutes later.
The launch of a NASA research satellite built to probe conditions along the boundary between Earth’s atmosphere and space has been tentatively rescheduled for no earlier than Wednesday, pending the conclusion of a review of unexpected data signatures discovered on the first stage of the mission’s air-launched Pegasus XL rocket.
