Ariane 5 set to launch two communications satellites
On Wednesday, June 8, Arianespace is slated to conduct its fifth mission of 2016 by sending a duo of communications satellites into space. The spacecraft are poised to be launched atop an Ariane 5 booster between 4:30 p.m. and 5:15 p.m. EDT (20:30 and 21:15 GMT) from the Ariane Launch Complex No.3 (ELA-3) at the Guiana Space Centre in Kourou, French Guiana.
The mission, designated VA230 in Arianespace’s numbering system, will mark a new record for a total payload weight orbited by the Ariane 5 launcher during one flight. The rocket will send 10.73 metric tons aloft, including a net weight of 9.84 metric tons for the two satellites, surpassing the previous record set on Feb. 7, 2013, when the booster sent a total of 10.5 metric tons of payload (9.5 metric tons for the satellites) into space.
The VA230 mission has two passengers: EchoStar 18 satellite for the U.S. company Dish Network and the Indonesian BRIsat spacecraft that will be operated by Bank Rakyat Indonesia (BRI).
When launched, the two satellites will fly atop the Ariane 5 booster before EchoStar 18 separates at about 29 minutes into the flight. BRIsat is slated to be deployed approximately 13 minutes later. Both spacecraft will be inserted into a geostationary transfer orbit (GTO).
Arianespace commenced the VA230 launch campaign in late March 2016 when ground teams started preparing the launch vehicle at the Guiana Space Centre.
EchoStar 18 arrived first in Kourou on April 20 and was transferred to the S5C payload processing facility. The next day, fit-checks of the satellite were conducted, and on May 2, the spacecraft was transported to the S5B building.
Meanwhile, on May 3, the Ariane 5 booster was moved from the Launcher Integration Building to the Final Assembly Building. One week later, the BRIsat arrived in Kourou and was shipped to the S5C facility.
In mid-May, the EchoStar 18 satellite was integrated and encapsulated in the payload fairing. The same activities were conducted on BRIsat two weeks later, and by June, the two spacecraft were ready to be mounted onto the launch vehicle.
On June 1, the satellites were installed atop the Ariane 5 vehicle and, the next day, the launch rehearsal was carried out.
On Monday, June 6, the launch readiness review was conducted, signifying the rocket is now ready for its rollout to the launch pad, scheduled to take place on Tuesday, June 7.
Both spacecraft flying on the VA230 mission were built by Space Systems Loral (SSL) and are based on the company’s SSL 1300 bus. This platform has a total satellite power capability ranging from between 5 to 25 kilowatts and can support 12 to 150 transponders. The bus features a lightweight and high-strength structure, fuel-efficient attitude and station-keeping subsystems, high-efficiency and reliable solar arrays and batteries, as well as advanced command and control subsystems.
EchoStar 18 weighs around 6.3 metric tons and has dimensions of 27.23 by 11.5 by 9.5 feet (8.3 m × 3.5 m × 2.9 m). It has two deployable solar arrays that can generate up to 13 kilowatts of power during its designed lifetime of 15 years. The satellite features a high power multi-spot beam, Ku-band payload with 61 transponders.
EchoStar 18 will replace EchoStar 10 at the 110 degrees West location. It will provide Direct Broadcast Services (DBS) for customers in the contiguous United States, Alaska, Hawaii, Puerto Rico, and Cuba.
BRIsat is smaller than its co-passenger as it weighs about 3.54 metric tons and has dimensions of 18.37 by 11.5 by 10.17 feet (5.6 m × 3.5 m × 3.1 m). It is designed to be operational for up to 15 years, generating 9.5 kilowatts of power by utilizing its two deployable solar arrays. The spacecraft is equipped with a set of nine Ku-band transponders and 36 C-band transponders.
From its orbital position at 150.5 degrees East, BRIsat will provide enhanced secure banking communications for more than 10,600 operational branches of BRI, as well as to some 237,000 electronic channel outlets and nearly 53 million customers across the Indonesian archipelago.
The Ariane 5 in ECA configuration to be used in Wednesday’s launch is the heavy-lift rocket for missions to GTO and usually carries two telecommunications satellite payloads. It 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 communications 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 will be the 230th liftoff of an Ariane vehicle from the Kourou Spaceport. It will be the third Ariane 5 launch of 2016 (the 86th Ariane 5 launch overall), and the fifth of 12 flights planned this year by Arianespace utilizing its family of the heavy-lift Ariane 5, the medium-lift Soyuz, and the lightweight Vega.
Arianespace’s next launch is scheduled for July 12 when it is expected to send into orbit the DSN 1 satellite for the Japanese Ministry of Defense and the GSAT-18 spacecraft for the Indian Space Research Organisation (ISRO). The mission will be conducted by the Ariane 5 launcher in the ECA configuration. The rocket is slated to blast off from ELA-3 complex in Kourou.
Tomasz Nowakowski is the owner of Astro Watch, one of the premier astronomy and science-related blogs on the internet. Nowakowski reached out to SpaceFlight Insider in an effort to have the two space-related websites collaborate. Nowakowski's generous offer was gratefully received with the two organizations now working to better relay important developments as they pertain to space exploration.