Preparations continue with the JCSAT-12 and Optus D3 payloads for Ariane 5's next launch

(Arianespace) – Both spacecraft for Arianespace’s fourth heavy-lift mission of 2009 are well advanced in their integration phase as preparations move forward for the August 21 nighttime launch from French Guiana.

In the Spaceport’s S5 payload preparation facility, Optus D3 has been installed atop its adapter unit.  This cone-shaped component will serve as the interface between the satellite and Ariane 5’s core stage – where the relay platform will be positioned as the lower passenger in the payload “stack.”

Optus D3 is positioned for installation on its interface adapter unit inside the S5 payload preparation facility.

A few kilometers away, the payload stack’s upper element is complete, with Ariane 5’s payload fairing now lowered into place over the JCSAT-12 satellite and the SYLDA dispenser system.  This activity occurred in the launcher Final Assembly Building adjacent to the Ariane 5, which is ready to be fitted with its two passengers.

JCSAT-12 will have a liftoff mass of approximately 4,000 kg., and carries 30 Ku-band transponders plus 12 C-band transponders.  The high-power relay platform was built by Lockheed Martin Commercial Space Systems in Newtown, Pennsylvania, using the company’s A2100AX satellite bus.  It will join the fleet of Japan-based SKY Perfect JSAT Corporation, serving as the successor to JCSAT-R, which currently is in geostationary orbit as a backup relay platform.

Optus D3 was produced by Orbital Sciences Corporation of Dulles, Virginia, with the STAR spacecraft bus, and is outfitted with 32 Ku-band transponders for fixed communications and direct television broadcasting services to Australia and New Zealand.   With a liftoff mass of 2,500 kg., it will be operated by the Australia-based Optus communications provider.

The Ariane 5 payload fairing is readied to be lowered over JCSAT-12 and the SYLDA dispenser in the launcher Final Assembly Building.