CAPE CANAVERAL, Fla. — NASA's newest rocket blasted off on a brief test flight today, taking the first step in a back-to-the-moon program that could yet be shelved by the White House.

The 327-foot Ares I-X rocket resembled a giant white pencil as it shot into the sky, delayed a day by poor weather.

Nearly twice the height of the spaceship it's supposed to replace — the shuttle — the skinny experimental rocket carried no passengers or payload, only throwaway ballast and hundreds of sensors. The flight cost $445 million.

"Oh, man. Well, how impressive is that," said Jeff Hanley, manager of NASA's space frontier program, known as Constellation. "You've accomplished a great step forward for exploration," he told launch controllers.

It was the first time in nearly 30 years that a new rocket took off from Kennedy Space Center. Columbia made the maiden voyage for the shuttle fleet back in 1981.

Liftoff, in fact, occurred 48 years and one day after the first launch of a Saturn rocket, a precursor to what carried astronauts to the moon during the Apollo program. The Saturn V moon rockets were the tallest ever built, an impressive 363 feet.