Boeing Co. said Wednesday it had successfully launched its Delta IV heavy-lift rocket for the first time, but a demonstration satellite was placed at a lower orbit than planned.
The flight was a test for the U.S. Air Force ahead of a launch planned for next year using the heavy-lift rocket.
Boeing said preliminary data showed that the first-stage engines shut down prematurely, leading to the lower orbit for the demonstration payload.
"While the demonstration satellite did not reach its intended orbit, we now have enough information and confidence in the Delta IV Heavy to move forward with preparations for the upcoming Defense Support Program launch in 2005," said Dan Collins, vice president of Boeing Expendable Launch Systems.
The Defense Support Program satellites make up a network that the U.S. military uses to detect missile and space launches as well as nuclear detonations around the globe.
Boeing has said previously that a successful test of the Delta IV rocket would clear the way for at least one launch next year of a military satellite.
An Air Force official was not immediately available for comment on Delta IV flight.
The rocket lifted off the launch pad in Florida on Tuesday afternoon. A previous launch attempt was scrubbed Dec. 12 after a temperature control system malfunctioned.
Boeing is vying with Lockheed Martin Corp. for U.S. government contracts to loft military and spy satellites as heavy as 50,000 pounds into low-Earth orbit.
On Dec. 17, Lockheed successfully launched a communications satellite using its Atlas V rocket, a vehicle it says could be modified for heavy-lift capability in about 30 months.
Boeing and Lockheed, which developed their newest rockets under the Air Force's Evolved Expendable Launch Vehicle program, are competing for the lion's share of the program, valued at $5 billion.
Boeing, which initially had a leading role, has been suspended from bidding on future rocket launch work. Tuesday's launch and next year's planned launch predated the suspension.
The Air Force suspended Boeing in July 2003 after concluding it illegally obtained thousands of Lockheed documents during bidding for the initial 1998 contract.
Federal prosecutors continue to investigate the case.
The Air Force said on Monday it had awarded Lockheed a contract to launch a classified spy satellite from its newly built West Coast facility by July 2006 for undisclosed terms.