A planned July 31st launch of an Ariane 5 rocket carrying three important communication satellites was cancelled with less than two minutes to launch. The launch should have happened at 5.29pm French Guiana time.
The problem was related to “unexpected behaviour” in the rocket’s main cryogenic stage and efforts to restart the countdown within the launch window were unsuccessful.
Arianespace say that the rocket and its cargo have been returned to the safety of the site’s Final Assembly Building. A new launch date and time will be announced on August 3rd. Meanwhile, a replacement sensor will be fitted and a new flight plan calculated.
Three separate spacecraft comprise the dual-launch payload for this mission, including Intelsat’s Galaxy 30, Mission Extension Vehicle-2, and BSAT-4b.
The Galaxy satellite is the first of a wider replacement effort for Intelsat’s fleet of 13 Galaxy craft.
Riding in the lower passenger position inside the SYLDA (Système de Lancement Double Ariane — ‘Ariane Double-Launch System’) is BSAT-4b, a broadcasting satellite built by Space Systems/Loral (SSL), a subsidiary of Maxar Technologies. The satellite is based on the SpaceSystems/Loral-1300 spacecraft bus.
BSAT-4b is owned and operated by Broadcasting Satellite System Corporation (BSAT), which provides communication and broadcasting satellite services for Japan. The BSAT spacecraft will serve as a backup to BSAT-4a, which was launched in September 2017 aboard an earlier Ariane 5 mission. BSAT-4b is identical to 4a.
The 3,520 kg satellite uses 24 Ku-Band (12-18 GHz) transponders and will be capable of broadcasting 4K/8K ultra-high definition media DTH over Japan.