A successful launch has placed the Superbird-7 and AMC-21 telecommunications satellites into accurate geostationary transfer orbits. This was the 9th mission performed by Ariane 5s in a 12-month period, during which the workhorse vehicles carried 16 civilian and military telecommunications satellites along with the first Automated Transfer Vehicle (ATV) for the International Space Station. The combined total payload weight equals 75,430 kg. Thursday's flight also marked the Ariane 5's 27th consecutive successful launch, and was the fifth of seven missions planned by Arianespace in 2008.

The heavy-lift Ariane 5 ECA's on-time liftoff occurred at 5:44 p.m. local time in French Guiana, and provided a daytime view of the vehicle's trajectory as it headed downrange from the Spaceport. Superbird-7 rode in the upper position of Ariane 5's dual payload "stack" and was released first during the half-hour mission, obtaining separation 26 minutes into the flight. The spacecraft was orbited by Arianespace for Japanese operator Space Communications Corporation (SCC) in the framework of a contract with Mitsubishi Electric Corporation. Once positioned at its orbital slot of 144° E, Superbird-7 will succeed SCC's current Superbird-C satellite and is designed to provide a wide range of Ku-band telecommunications services with enhanced performance. Superbird-7 is based on the Mitsubishi Electric Corporation's DS2000 satellite platform, and it had a liftoff mass of 4,820 kg.

AMC-21's deployment as Ariane 5's second satellite passenger on Thursday's mission occurred from the launcher's lower payload position 30 minutes after liftoff. This 2,500-kg. spacecraft was manufactured by Thales Alenia Space and incorporates the Orbital Sciences STAR-2 satellite bus. AMC-21 will operate from SES' new 125° W orbital position. The relay capacity provided by AMC-21 will be marketed by the U.S.-based SES AMERICOM, which is to offer the advanced Ku-band telecommunications links for mobile applications and TV broadcasting. Coverage will include the 50 U.S. states, as well as Southern Canada, Mexico, Central America and the Caribbean. AMC-21 was the 30th satellite launched by Arianespace for the SES group, building on the two companies' association that spans nearly 25 years. Arianespace's first ever mission — performed in 1984 with an Ariane 1 launcher — orbited SPACENET 1, which was operated by one of the SES group's predecessor companies. Two more flights are planned, making this the busiest calendar year since the Ariane 5's commercial introduction in 1999. Company Chairman & CEO Le Gall announced the next Ariane 5 mission is set for the end of October, another dual-satellite payload: Eutelsat's HOT BIRD 9 and NSS-9 for SES NEW SKIES. In addition, this flight will carry two auxiliary passengers, a pair of French Spirale satellites that are demonstrators for a space-based military optical early warning system.