Sending satellites into space from the sea

Long Beach-based Sea Launch sends commercial satellites into space using a self-propelled former oil platform as a launch pad. The unique system uses the partially submerged platform and an accompanying command ship to launch rockets for customers that have included DirecTV and XM Satellite Radio. Its next launch, the company’s 24th, is set for Saturday. How it works:

Preparing for the voyage

1. Rocket components are loaded onto ship

The rocket’s three stages and payload are brought separately to Sea Launch’s warehouse in Long Beach Harbor, loaded onto the assembly and command ship, Commander, and assembled.

2. Rocket is transferred to launch platform

Still in the harbor, the integrated launch vehicle is lifted 200 feet into the launch platform’s hangar using cables and 50-ton cranes.

3. Both vessels proceed to launch site

The self-propelled launch platform, Odyssey, gets a head start since it travels slower. Both vessels meet at the launch site, about 3,000 miles away, 11 days after the Odyssey departs.

At sea

Propulsion: The platform is propelled by two engines in each pontoon. It operated previously as an oil rig in the North Sea and weighs 46,000 tons.

At the launch site

Ballast: The pontoons are filled with water as ballast to sink the platform 65 feet, giving it a stable foundation for launch.

The launch and orbit

- A spot on the equator is used for its benign weather.

- Approximately one hour after launch, the final separation of the satellite takes place. Several hours later it reaches its apogee and from there it takes a few days to get into its correct geostationary orbit 22,300 miles above the equator, where it stays synchronized with the Earth’s rotation.

- Most of the satellites have a life span in orbit of 12 to 15 years.

Ready to launch

The rocket is moved from the hangar to the launch pad and all of the personnel are moved off the launch platform onto the assembly and command ship, which conducts the launch remotely three miles away. Saturday’s launch will be carried live on the Sea Launch website at www.sea-launch.com.

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Source: Sea Launch

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