With its first launch expected early in 2002, the Delta 4 represents Boeing's contribution to the Air Force's Evolved Expendable Launch Vehicle program, an effort designed to give the nation a new generation of unmanned rockets that will cost some 25 percent less to operate. Lockheed Martin is developing its Atlas 5 family of rockets for the same program.

A key feature of the Delta 4's operation is the use of a Common Booster Core, or CBC, a rocket stage that measures some 150 feet (45 meters) long and 16 feet (5 meters) wide.

By combining one or more CBC's with various upper stages or strap-on solid rocket boosters, the Delta 4 can handle an extreme range of satellite weights for military, civilian and commercial customers.

And it's these CBC's that the Delta Mariner -- which is about the length of a football field -- was designed to move from their manufacturing plant in Decatur, Ala., to a coastal launch site.

Up to three CBC's and associated upper stage, nose cone and other equipment can sail inside the ship's high-volume cargo bay at the same time, enough for one heavy-lifting Delta 4 mission.

Boeing officials hope to move some 16 to 18 CBC's to the Cape each year, which depending on how they are used could be enough for at least six heavy-lift Delta 4 missions, or many more flights that use only one CBC per mission.

There's room for three Delta 4 Common Booster Core rocket stages inside the Delta Mariner's main cargo hold as illustrated in this cut away view. Boeing image.

It's not the first time that rocket stages have been delivered by sea. NASA's external tank for the space shuttle has always been transported to the Kennedy Space Center by barge, as were the largest components of the Saturn 5 Moon rocket during the 1960s and 1970s.

But this is the first time that rockets destined to fly from the Cape have finally grown so large that routine water delivery to Port Canaveral has become a necessary consideration.

Christened the Delta Mariner during a Dec. 16, 1999 launch ceremony, the rocket carrying ship passed its sea trials in April 2000 and then spent some time at Foss Maritime's Gulf Caribe operation in Mobile, Ala., for outfitting and crew training.

During October 2000 the ship made its first run through the Gulf of Mexico, around the Florida peninsula, to its own wharf at Port Canaveral.

"It's a wonderfully handling boat," Lloyd Patten, the ship's master, said from the Delta Mariner's bridge after that trip. "It's very maneuverable and has got plenty of horsepower. She'll do anything that we ask of her."

Patten spent 24 years working on oil tankers, mostly making the pipeline run out of Valdez, Alaska. He had "sort of retired" from Atlantic Richfield when a phone call from a colleague sent him on path that led to becoming captain of the Delta Mariner.

"This was very refreshing to come down here and get off tankers that are pretty much standard, and come down to a state-of-the-art vessel and all of this modern stuff," Patten said.

Now the seasoned mariner with no previous interest in space is working with rocket scientists who know little about the sea. Together they are writing a whole new set of rules about how to deliver futuristic launch vehicles using one of the oldest forms of human transportation.

"They're trying to learn about the vessel and how its going to work, and where it can go and can't go, and we're interested in the rockets," Patten said. "It's been interesting to see how it's all going to coordinate."

So far everything seems to be going well.