The first of the Air Force's powerful new $150 million Titan 4 space rockets was transported to a launch pad Saturday under curious censorship.

The 20-story-tall rocket, the largest unmanned booster in the U.S. space stable, is scheduled to make its maiden flight next October, boosting a classified military reconnaissance satellite.Development of the Titan 4 was accelerated following the explosion that destroyed space shuttle Challenger in 1986. The grounding of the shuttle fleet left several critical national security payloads without a way to get into space, and many of those will be hoisted by the new rocket.

The Air Force, which held a media extravaganza here in January when the first rocket was delivered and its launch pad was dedicated, originally said the news media would be escorted to the pad to cover Saturday's rollout.

But Air Force Secretary Edward C. Aldrich, who presided at the January festivity, ruled the media out earlier this week, with the Pentagon explaining only that, "the launch sequence of military launch vehicles is not typically an item of public discussion."

But when the decision was made Saturday to move the Titan 4, Air Force public affairs officials alerted the news media at their homes by phone. They also made arrangements to release photographs, film and videotape of the move.

Air Force Lt. Col. Ron Rand, director of public affairs at the Eastern Space and Missile Center, replied, "absolutely none," when asked if there were any security or safety reasons for barring the press Saturday.

A Titan 34D, predecessor of the Titan 4, is being readied on an adjacent pad for a secret military launching, but Rand said that had no bearing on the ruling.

The rocket was visible for miles during its 45-minute move to the launch pad from an assembly building. The closest point for the public to see it was about six miles away.

The launch pad debuts of previous space rockets have been open to news coverage here.

Martin Marietta is building 23 Titan 4s for the Air Force at its plant near Denver. The Pentagon is seeking millions in public funds to build an additional 27 boosters.

Col. Lawrence Gooch, commander of the Eastern Space and Missile Center, issued a statement saying, "The rollout of the Titan 4 is another major step toward recovering our space launch capability."

From Washington, Aldrich said, "The Titan 4 program is one of the cornerstones of our national security strategyto rebuild assured access to space. This booster represents the new workhorse of space for our nation."

For the next several months, a team of specialists from the Air Force and Martin Marietta Astronautics Group will check the compatibility of the rocket with the new launch pad and prepare the vehicle for launch.

The Air Force plans to launch two Titan 4 rockets a year from Cape Canaveral to boost military satellites for such assignments as reconnaissance, communications and communications intercept. Other launches are scheduled from Vandenberg Air Force Base, Calif.

The Titan 4 can boost 32,000-pound payloads into low Earth orbit and 10,000 pounds to stationary orbit 22,300 miles high, where most military satellites are based.