The spacecraft integration activity began yesterday (August 10) with JCSAT-12's installation atop the Ariane 5 SYLDA dual-payload dispenser system. This activity took place inside the Spaceport's launch vehicle Final Assembly Building, where mission team members are preparing JCSAT-12 in a clean room area adjacent to the Ariane 5.
JCSAT-12 will ride as the flight's upper passenger and is to be deployed first in the mission sequence, with its release from atop the SYLDA dispenser occurring at approximately 27 minutes into the mission. The cylindrical-shaped SYLDA structure will then be jettisoned, exposing Ariane 5's lower passenger, the Optus D3 spacecraft, which will be deployed at just over 34 minutes after liftoff.
The JCSAT-12 payload is a high-power hybrid relay platform produced by Lockheed Martin Commercial Space Systems in Newtown, Pennsylvania, using the company's A2100AX satellite bus. It will be utilized by Tokyo, Japan-based SKY Perfect JSAT Corporation, which is one of Asia's largest satellite operators.
With a liftoff mass of approximately 4,000 kg., JCSAT-12 carries 30 Ku-band transponders and 12 C-band transponders. This spacecraft will serve as the successor to JCSAT-R, which currently is in geostationary orbit as a backup relay platform, ensuring the stability of SKY Perfect JSAT's satellite fleet for highly reliable space-based communications services.
JCSAT-12 has a design lifetime of 15 years, and will offer coverage over Japan, the Oceania and Asia-Pacific regions, as well as Hawaii. Once operational, it will be referred to as JCSAT-RA.
The other passenger for Arianespace's upcoming Ariane 5 mission, Optus D3, will be operated by the Australia-based Optus communications provider, and has a liftoff mass of 2,500 kg. This satellite was built by Orbital Sciences Corporation of Dulles, Virginia, and is equipped with 32 Ku-band transponders for fixed communications and direct television broadcasting services to Australia and New Zealand.
Liftoff of the August 21 mission is scheduled at the start of a one-hour launch window that opens at 7:09 p.m. local time in French Guiana.
Arianespace is planning seven Ariane 5 missions in 2009, with the August 21 flight to be its fourth of the year. The previous launches were conducted on July 1, (withTerreStar-1, the world's largest commercial satellite), on May 14 (with Europe's Herschel and Planck deep space telescopes), and on February 12 (orbiting the HOT BIRD 10 and NSS-9 commercial telecommunications satellites, along with a pair of Spirale auxiliary passengers for the French defense procurement agency).