The spacecraft was designed and manufactured by Lockheed Martin on the A2100AXsatellite bus. It had a launch mass of 4,007 kg (8,834 lb) and a 15-year design life. A near copy of JCSAT-3A, it was to be used as an on orbit spare.[2] As most satellites based on the A2100 platform, it uses a 460 N (100 lbf) LEROS-1CLAE for orbit raising.[2] Its solar panels span 27 m (89 ft) when fully deployed and, with its antennas in fully extended configuration it is 9 m (30 ft) wide.[3]
Its payload is composed of eighteen 27 MHz and twelve 36 MHz Ku band plus twelve C bandtransponders, for a total bandwidth of 1,350 MHz.[4] Its high-power amplifiers had an output power of 127 Watts on Ku band and 48 Watts on C band.[3]
History
On October 3, 2005, JSAT ordered an A2100AX based satellite from Lockheed Martin, JCSAT-11. It would be an almost copy of JCSAT-3A, with a C band and Ku band payload. It was expected to be launched in 2007 to act as a backup for the whole JSAT fleet.[5]
The almost 19-year streak of successful JCSAT launches was ended when a Proton-M/Briz-M failed to orbit JCSAT-11 on September 5, 2007. A damaged pyro firing cable on the interstage truss prevented the second stage from controlling its direction, and the rocket and its payload crashed into the Kazakhstan steppes.[6] Being lucky in misfortune, JCSAT-11 was simply an on-orbit backup and thus it had no operational impact on the fleet.[2]
The same day of the launch failure, JSAT placed an order with Lockheed for an identical replacement, JCSAT-12, for launch in 2009.[2] On September 19, 2007, they closed a deal with Arianespace for a launch slot with an Ariane 5 for its launch.[7]
Launches are separated by dots ( • ), payloads by commas ( , ), multiple names for the same satellite by slashes ( / ). Crewed flights are underlined. Launch failures are marked with the † sign. Payloads deployed from other spacecraft are (enclosed in parentheses).