Space Shuttle External Tank Begins Its Journey to Space Via Barge
The longest journey for the Space Shuttle's external tank isn't its 69-mile climb during the Shuttle's eight-and-a-half-minute liftoff and ascent into space. Just what is? Here's a hint: Take your seasick pills!
The external tank's longest journey is an approximate 1,000-mile trip by covered barge from NASA's Michoud Space Systems Assembly Facility near New Orleans, around the tip of Florida, to NASA's Kennedy Space Center, about half-way up Florida's Atlantic coastline. It does, in fact, spend more time on the water than in the air.
Image right: External Tank 120 -- the tank that will return the Space Shuttle to flight -- rolls out at Michoud Assembly Facility in New Orleans on Dec. 31, 2004. (Image credit: Lockheed Martin/NASA Michoud)
The external tank that will help launch Space Shuttle Discovery on its next mission -- slated for late spring 2005 -- left New Orleans Dec. 31 for its five day, coast-hugging trek from the Mississippi River-Gulf of Mexico Outlet to Florida's Banana River, which flows into the Atlantic Ocean.
Shipping tank number 120 is an important milestone for the NASA team that has spent 23 months working on modifications that will make the tank safer during liftoff.
The gigantic, rust-colored external tank is the largest element of the Space Shuttle system, which includes the orbiter, main engines, solid rocket boosters and the tank. It measures 154 feet tall and 27.6 feet wide -- as long as half a football field and as wide as four sport utility vehicles parked side-by-side. The tank is the only Shuttle component that cannot be reused.
The delivery process begins when the tank -- mounted on a wheeled transport platform -- is towed by tractor the one-mile distance from Michoud's tank assembly building to the dock where a 225-foot-long barge awaits. It requires about eight working hours and an eight-man crew to move the tank from the building and load it onto the barge. Then the tank and its transport platform are secured on the barge using hydraulic locks to reduce load shifting and vibration during the voyage.
Image right: External Tank 120 is loaded onto its covered barge and prepared for shipment at Michoud Assembly Facility in New Orleans on Dec. 31, 2004. (Image credit: Lockheed Martin/NASA Michoud)
Once secured, the barge is towed by one of two ships -- the Liberty Star or the Freedom Star -- that NASA also uses to retrieve the Shuttle's solid rocket boosters after a launch.
Once the ship and barge leave the Mississippi River Delta, the ship's captain steers a course across the Gulf of Mexico heading for the southern tip of Florida. While in open waters, the barge is actually towed about one-quarter-of-a-mile behind the ship, making it easier for the 12-person crew to handle in the ocean's strong currents.
Bren Wade, captain of the Liberty Star, which is towing ET-120, appreciates the important role he and his crew play. Wade, who grew up in Cocoa Beach, Fla., near Kennedy Space Center, remembers his grandfather working at Kennedy during the 1960s on Gemini missions. "All of us are excited about delivering this tank," says Wade. "It's an important step in returning the Shuttle safely to flight."
After passing through the Florida Keys, the Liberty Star will travel up the Atlantic coast to Port Canaveral -- the harbor for Kennedy Space Center. The tugboats will take control of the barge once it approaches Kennedy, towing it up the Banana River to the launch complex dock for unloading and the tank's trip to the Vehicle Assembly Building.
The Space Shuttle Propulsion Office at NASA's Marshall Center manages the tank project. Lockheed Martin Space Systems Co., in New Orleans, is the primary contractor.
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June Malone, Marshall Space Flight Center