All is ready for the countdown leading to a liftoff on July 1 during a launch window that opens at 6:43 pm local time (21:43 GMT) on Arianespace’s fourth mission in 2011. The two passengers for this flight are the Astra 1N and BSAT-3c/JCSAT-110R DTH satellites.

To be deployed first during the 38-minute mission is Astra 1N, which was built by EADS Astrium in Toulouse, France for the Luxembourg-based operator SES Astra. Based on Astrium’s Eurostar E3000 platform, Astra 1N has an estimated liftoff mass of 5,350 kg. and is fitted with 52 active Ku-band transponders. It initially is to deliver interim capacity from an orbital position of 28.2 degrees East, and subsequently will move to SES Astra’s prime location at 19.2 degrees East for primary and backup services during a designed operational lifetime of 15 years.

BSAT-3c/JCSAT-110R was manufactured by Lockheed Martin Commercial Space Systems at its plant in Newtown, Pennsylvania as part of a turnkey contract for Japanese operators B-SAT Corporation and SKY Perfect JSAT Corporation. Produced using an A2100 A platform, this satellite will weigh approximately 2,910 kg. at launch, and is to be positioned at 110 degrees East longitude in geostationary orbit, and offers a design life exceeding 16 years. BSAT-3c/JCSAT-110R is fitted with 24 active Ku-band transponders, and is primarily designed to provide direct TV broadcast links for all of Japan.

The July 1 mission follows Arianespace’s previous Ariane 5 flights in 2011 that orbited the ST-2 and GSAT-8 telecommunications satellites on May 20; the Yahsat Y1A and Intelsat New Dawn relay spacecraft on April 22; and the Johannes Kepler Automated Transfer Vehicle for servicing of the International Space Station on February 16.

You can follow the launch live on the special Arianesapce videocorner website. Before the launch, a videoclip on the prepartion of the launch can be seen. The launch can also be seen live on Astra`s orbital position 19.2 degrees East, transponder 1.037, downlink frequency 11023.25 Mhz/H, symbol rate 22.0 MSym/s, FEC 5/6, service ID 5232, service name Astra 1N launch.