One of the main selling features of NASA's Space Shuttle was the idea of reusing its key components. The orbiter vehicle and its main engines, plus the most powerful set of solid rocket boosters ever built, are used time and time again. Part of NASA's fleet are a pair of specialty ships, Freedom Star and the Liberty Star, designed to retrieve the spent solid rocket motors after initial take-off. Both ships, products of the Atlantic Marine Shipyard near Jacksonville, Florida, were built in 1980. The Liberty Star, pictured here at the Kennedy Space Center, spans 176 feet, and is powered by twin 1,450 horsepower diesels. Special thrusters are built into the hull, allowing the ship to move in all directions, making its main task somewhat easier.
On launch day, the ships wait offshore about 10 miles from the rocket booster splashdown area just off the Florida coast. Nobody wants to be too close when the 165,000 pound rocket casings plunge in the Atlantic Ocean. Once the boosters are located, divers insert a large semi-buoyant plug into the business end of the rocket. Air is pump in, displacing all the water in the empty combustion chamber. Once afloat, the booster is attached to the ship and towed back to the refurbishment facility.
In order to provide tracking on launch day, the retrieval ships are pre-positioned just offshore from the Florida launch pad. Both are equipped with radar to track the Space Shuttle's ascent. In addition to launch day duties, the ships assist on moving the Shuttle's main fuel tank, the only Shuttle component not reused. The external fuel tank is built in Michoud, Louisiana, and requires a 12 day round trip for pick-up and delivery.