A tugboat pulls the Pegasus Barge through a drawbridge after leaving NASA's Kennedy Space Center in Florida.

A tugboat pulls the Pegasus Barge through a drawbridge after leaving NASA's Kennedy Space Center in Florida. The 266-foot-long and 50-foot-wide barge will be towed by NASA's Freedom Star ship to deliver space shuttle main engine (SSME) ground support equipment to Stennis Space Center near Bay St. Louis, Miss. Since being delivered to NASA in 1999, Pegasus sailed 41 times and transported 31 shuttle external fuel tanks from Michoud Assembly Facility near New Orleans to Kennedy.

The barge is leaving Kennedy, perhaps for the final time. Both the barge and shuttle equipment will remain in storage until their specific future uses are determined. The SSMEs themselves will be transported to Stennis separately for use with the agency's new heavy-lift rocket, the Space Launch System. The work is part of the Space Shuttle Program’s transition and retirement processing. For more information about Shuttle Transition and Retirement, visit http://www.nasa.gov/mission_pages/transition/home/index.html. Photo credit: NASA/Frankie Martin