From its equatorial launch site at 154 degrees West Longitude, the Sea Launch rocket lifted the Galaxy XIII/Horizons-1 satellite to a lofted perigee geosynchronous transfer orbit (GTO) on the way to its final orbital position at 127 degrees West Longitude. The spacecraft carries a total of 48 active transponders, 24 in Ku-band and 24 in C-band. While it is designed for a 15-year lifespan, Sea Launch's direct insertion into equatorial orbit is expected to yield several additional years of service.

Built by Boeing Satellite Systems in El Segundo, Calif., the Boeing 601HP spacecraft is designed to offer a variety of digital video, Internet and data services to North America, Central America, Alaska and Hawaii. Horizons-1 is jointly owned by PanAmSat and JSAT, and supports their Horizons venture, providing expanded Ku-band services in North America and extended services to Japan and Asia via a Hawaii-based relay station. The C-band payload, Galaxy XIII, which is operated independently by PanAmSat, offers the first high-definition neighborhood in the U.S. cable arc.

PanAmSat Corporation is the premier provider of global video and data broadcasting services via satellite. Operating a global network of 21 in-orbit spacecraft and seven technical facilities, the company delivers entertainment and information to cable television systems, TV broadcast affiliates, direct-to-home TV operators, Internet service providers, telecommunications companies and corporations worldwide.

JSAT Corporation is a leading satellite operator in the Asia-Pacific region. Based in Tokyo, the company owns and operates eight satellites in seven orbital slots. JSAT provides communications and broadcasting services that offer a range of unique features made possible by satellite communications which is well suited to support the high-volume, wide-distribution, high-speed networks.

Sea Launch's reliable Zenit-3SL rocket lifted the 4090 kg (9081 lb) Galaxy XIII/Horizons-1 satellite to geosynchronous transfer orbit, with the spacecraft separating from the Block DM-SL upper stage about 4000 miles above the Atlantic Ocean, west of Gabon, Africa. The launch originated from the Odyssey Launch Platform, positioned on the Equator at 154 degrees West Longitude. Two and a half minutes after liftoff, the first stage separated and, a minute later, the payload fairing jettisoned. About five minutes later, the second stage separated from the Block DM-SL upper stage. After the first of two burns of the Block DM-SL, the spacecraft coasted for 30 minutes. Following this coast period, the Block DM-SL made a second burn and then separated from the spacecraft about 11 minutes later. A ground station in Fucino, Italy, acquired the first signal from the spacecraft shortly after separation. This mission used a standard GTO trajectory, which places the payload into a higher energy state. After the payload circularized itself at geosynchronous orbit altitude, the spacecraft performed a series of maneuvers over several days to place the spacecraft into its final position in geostationary orbit at 127 degrees West Longitude.