The first Ariane 5 rocket scheduled for launch in 2018 has been topped off with two communications satellites for SES and Yahsat, moving the European booster closer to liftoff Thursday from a tropical launch pad in French Guiana with payloads to serve commercial and scientific missions.
Technicians working inside the final assembly building at the Guiana Space Center hoisted the SES 14 and Al Yah 3 communications satellites atop the Ariane 5 rocket last week, crowning the 180-foot-tall (55-meter) launcher ahead of final arming, a countdown rehearsal and a key readiness review Tuesday to give the go-ahead to transfer the Ariane 5 to its launch pad.
Pulled on a mobile launch platform behind a diesel-powered tug, the Ariane 5 will make the 1.7-mile (2.7-kilometer) trip to the ELA-3 launch zone Wednesday, ahead of the start of the final countdown Thursday.
Liftoff Thursday is set for a 45-minute window opening at 2220 GMT (5:20 p.m. EST; 7:20 p.m. French Guiana time).
The Al Yah 3 and SES 14 satellites arrived in French Guiana from their manufacturing plants in Virginia and France on Nov. 29 and Dec. 22, respectively.
Al Yah 3, the first satellite built on Orbital ATK’s enlarged GEOStar 3 satellite design, was filled with its maneuvering propellant in mid-December. The SES 14 spacecraft, built by Airbus Defense and Space, was fueled in early January.
The satellites were transferred from their clean room processing cells to the final assembly building earlier this month to meet the Ariane 5 launcher.
SES 14, the bigger of the two satellites, will ride in the upper position in the Ariane 5’s payload shroud. Ground crews installed the 9,751-pound (4,423-kilogram) spacecraft on top of the Ariane 5’s Sylda dual-payload adapter Jan. 12, then lowered the Ariane 5’s composite Swiss-built payload fairing over SES 14 and the Sylda structure Jan. 15.
Technicians attached the Al Yah 3 satellite, which resides in the lower berth of the Ariane 5 fairing, directly to a connector mounted on the rocket’s second stage. The 8,366-pound (3,795-kilogram) spacecraft is owned by Al Yah Satellite Communications Co. based in Abu Dhabi.
The final step in the Ariane 5’s assembly occurred Jan. 17, when workers lowered the fairing — containing SES 14 and the Sylda adapter — over Al Yah 3, which will sit cocooned inside the hollow Sylda during liftoff.
The SES 14 spacecraft, owned by Luxembourg-based SES, will provide aeronautical and maritime mobility connectivity, wireless communications, broadband delivery, and video and data services over North, Central and South America, the Caribbean, the North Atlantic and parts of Europe, replacing the NSS-806 satellite.
A NASA-funded instrument will fly piggyback on SES 14, collecting data on the region where Earth’s uppermost atmospheric layers interact with the environment of space. Scientists hope the instrument, known as GOLD, will yield improved space weather forecasts, helping predict when solar storms can impact infrastructure on the ground and in space.
Al Yah 3 will support broadband Internet and data services over Africa and Brazil.
After liftoff from the European-run space base in Kourou, French Guiana, the Ariane 5 rocket will deliver the satellites into a supersynchronous transfer orbit stretching between an altitude of 155 miles (250 kilometers) and 27,961 miles (45,000 kilometers), tilted at an angle of 3 degrees to the equator.
It will be the 241st flight of an Ariane rocket since 1979, and the 97th Ariane 5 launch since 1996.
Photos of the payloads being prepared for attachment to the Ariane 5 rocket, along with images of the launcher’s final assembly and the placement of logos on the fairing, are posted below.
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