A secret new spy satellite circled the globe in a useless orbit Saturday, leaving the United States to continue relying on aging systems for eavesdropping and warning of missile attacks.

The satellite, said to be designed for intercepting Soviet communications, was propelled into a successful preliminary orbit by a $65 million Titan 34D rocket launched here Friday.But a source close to the project said the spacecraft failed to achieve a desired stationary orbit 22,300 miles high when the upper stage of the rocket failed to re-ignite.

The source, who spoke on condition of anonymity, said the satellite remained in a sharply elliptical orbit ranging from about 100 to 22,300 miles above Earth.

He said the payload was useless on that course and there was little hope of salvaging the mission.

The Air Force, as is its custom with military launches, did not announce the liftoff in advance. Several minutes after launch, with the Titan apparently working well, it reported the mission's successful start.

John E. Pike, a space policy expert for the Washington-based Federation of American Scientists, said the satellite was code-named Vortex, a series designed to monitor Soviet missile tests and military and diplomatic electronic communications.

It was intended to replace a satellite that has been in use for several years and is showing signs of wear, the source reported.