The Pegasus Barge is a cargo transportation barge built for NASA in 1999 to ship the Space Shuttle’s external tanks to Florida for launch. Following the end of the Space Shuttle program, the barge was refurbished and lengthened for use in the SLS program, where it delivers the core stage and other components to Florida.

Pegasus was designed specifically to transport the large Space Shuttle external tanks (ET) from the factory in Louisiana to the launch site in Florida. First sailing in 1999, Pegasus continued in this role until 2011 when the program ended.

In 2014 the barge was assigned a new role in NASA’s new SLS program where it would transport the core stage, and other large components, to Florida for launch. The SLS core stage is longer than the Space Shuttle ET so the barge required a complete refurbishment and was extended from 260ft to 310ft. 

Since the refurbishment, the barge has made numerous trips to Florida carrying SLS components including the core stage for Artemis-1, which launched in November 2022.