Two unique ships form the marine infrastructure of the Sea Launch system. The first is a custom-built Assembly and Command Ship (ACS), and the second is the Launch Platform (LP), a semi-submersible vessel which is one of the world's largest ocean going launch platforms. Both vessels are equipped with spacecraft handling and launch support systems.

The Assembly and Command Ship—or ACS—is an all-new, specially designed vessel that serves as a floating rocket assembly factory while in port, provides crew and customer accommodations, and also houses mission control facilities for launches at sea. The ship was built at the Govan Shipyard in Glasgow, Scotland. In the fall of 1997, the ship sailed for Russia, where special equipment for handling rocket components and for commanding and controlling launches was installed and tested. It arrived in Long Beach, Calif., on July 13, 1998, after a voyage through the Panama Canal.

The ACS is 660 feet long, approximately 106 feet wide, with a displacement of more than 34,000 tons and has a cruising range of 18,000 nautical miles. The ACS provides accommodations for up to 240 crew members, customers and VIPs—including medical facilities, dining room, recreation and entertainment facilities.

The Launch Platform—or LP—a former North Sea oil drilling platform, was refurbished at the Rosenberg Shipyard in Stavanger, Norway. The vessel is one of the largest semi-submersible, self-propelled vessels in the world at 436 feet long, about 220 wide, with an empty draft displacement of 30,000 tons, and a submerged draft displacement of 50,600 tons.

   The Launch Platform provides accommodations for 68 crew and launch system personnel—including living, dining, medical and recreation facilities. It is equipped with a large, environmentally controlled hangar for storage of the Sea Launch rocket during transit, and with mobile transporter/erector equipment that is used to roll out and erect the rocket in launch position prior to fueling and launch. Special facilities onboard enable the storage of rocket fuels (kerosene and liquid oxygen) sufficient for each mission.

Customer spacecraft are processed in the specially designed Payload Processing Facility. Here, the payload, typically a large telecommunications satellite bound for geostationary orbit—is loaded with fuels, encapsulated within a payload fairing and prepared for mating with the Sea Launch rocket.

Once it has been thoroughly checked out by customer technicians, the encapsulated payload is rolled out to the ACS and integrated with the launch vehicle. Vehicle and spacecraft segments are mated with the launch vehicle in a horizontal orientation. The fully integrated launch vehicle is then transferred by an onboard crane system from the ACS to the Launch Platform.

Launch Control Center is located on the Assembly and Command Ship with special units of operations for English-speaking and Russian-speaking launch teams. Operations are managed in two-way translation services. All countdown launch, and telemetry and tracking data are observed and directed from this center.