High Quality Content by WIKIPEDIA articles! The NASA recovery ships are two ships, the MV Liberty Star and the MV Freedom Star that are tasked with retrieving spent Solid Rocket Boosters (SRBs) following the launch of Space Shuttle missions. Although owned by NASA, the ships are currently operated by Space Flight Operations contractor United Space Alliance. Both ships were built at Atlantic Marine Shipyard on Fort George Island, Florida, and delivered in January 1981 to their original owner, United Technologies Inc. They are propelled by two main engines providing a total of 2,900 horsepower (2.2 MW), and are capable of towing 60,000 pounds (27,000 kg) each. Two auxiliary engines with jacuzzi-like jets (similar to those found in Naval riverine craft) allow the ships to coast up the Banana River without harming the local manatee population.