CAPE CANAVERAL, Fla. - Fresh off its series of critical test firings, Boeing's Delta 4 pathfinder rocket has arrived at Cape Canaveral to ensure the state-of-the-art launch facilities being built at Complex 37 are ready to handle the maiden flight of the next-generation launcher in March.

The Common Booster Core is lifted out of the test stand at NASA's Stennis Space Center last Wednesday as the Delta Mariner awaits to carry the rocket to Florida. Photo: Boeing

The Common Booster Core was rolled off the Delta Mariner cargo vessel Tuesday morning after a 850-mile journey from NASA's Stennis Space Center in Mississippi where the rocket stage and new RS-68 engine underwent four successful "hot fire" tests over the past two months.

Riding on a specially-designed Elevating Platform Transporter, the 154-foot tall, 54,000-pound rocket stage then took a 9-mile trip up the road to Complex 37 to begin fit checks with ground equipment and the launch pad.

The rocket is off-loaded from Delta Mariner while riding on transporter. Photo: Justin Ray/Spaceflight Now

"The thrill level here right now is big," David Herst, Boeing's director of Delta 4 launch sites, said proudly as the rocket made its way out of the Mariner's cargo bay. "Finally we get our first production vehicle. This is good stuff."

Scheduled for tests through August, the rocket will pave the way for delivery of the first flight-worthy Delta 4 vehicle to the Cape in September.

The pathfinder vehicle was the first Common Booster Core to roll off the assembly line. The CBC serves as the first stage for all five versions the Delta 4 rocket family, which have the ability to lift cargos from 9,300 to 29,000 pounds to geosynchronous transfer orbit.

"It is obviously an important process," Herst said of the pathfinding work ahead. "It validates all of the facilities, our ground support equipment, procedures and personnel skills to make sure all the things we have been working on over the past couple of years are correct and in place before the first (flight) rocket gets out here."

As the pathfinder departs the port, the mighty size of the rocket is realized as it rolls past automobiles. The CBC is 154 feet in length and 16 feet in diameter. Photo: Justin Ray/Spaceflight Now

Workers on Tuesday took the pathfinder vehicle directly to the Horizontal Integration Facility -- the Delta 4 assembly hangar -- where it will undergo about six weeks of demonstrations to ensure tools, handling equipment and other hardware work with rocket.

Then in July, the rocket will be rolled horizontally to the launch pad and erected vertically on the mount. The massive mobile service tower will be moved around the vehicle and platforms lowered into place to ensure everything fits properly.

Since some versions of the Delta 4 feature strap-on solid rocket motors, an inert booster casing will be hoisted on the pad to check clearances and ensure the ground equipment works.

"We will do everything that we can do with a non-flight rocket before we put the first flight rocket up there," Herst said.

Fueling tests are not on the agenda since the pathfinder's umbilical connections don't match up with the launch pad. Those sorts of demonstrations and countdown rehearsals will be saved for the inaugural-launch rocket during trials this winter.

The rocket that will make the maiden Delta 4 mission is currently under final assembly and checkout at Boeing's Decatur factory in Alabama.

The rocket arrives at the Horizontal Integration Facility at Complex 37 on Tuesday afternoon. Photo: Boeing

Boeing has four Delta 4 launches scheduled in 2002:

• The inaugural flight is planned for March. Boeing is still seeking a commercial communications satellite to launch on the rocket.
  
  
• A mid-May launch will carry a Defense Satellite Communications System spacecraft into orbit for the U.S. Air Force.
  
  
• Another commercial mission is slated for October to carry the Estrela do Sul 1 communications satellite for Loral.
  
  
• A demonstration test flight of the Delta 4 Heavy vehicle configuration -- with three Common Booster Cores bolted together -- is expected in December for the Air Force.

As for the pathfinder rocket, once its chores are finished at the Cape in August, the booster will be set aside before being shipped late this year or early next to the Delta 4's West Coast launch site -- Vandenberg Air Force Base in California -- to undergo similar work.

Construction of the Vandenberg pad at Space Launch Complex 6 is still in the early stages since the first Delta 4 flight from there isn't planned until 2003.