LOS ANGELES, Jan. 20 (UPI) -- Thursday's launch of a 23-story Delta IV Heavy rocket, the tallest ever to blast off from California's Vandenberg Air Force Base was successful, officials said.
The launch took place on Vandenberg's Space Launch Complex 6, known on the base as "Slick Six," the Los Angeles Times reported.
The launch pad was built in the 1960s and was once intended to accommodate West Coast space shuttle launches, the newspaper said.
The Delta IV Heavy is built by United Launch Alliance, a joint venture of Lockheed Martin Corp. and Boeing Co.
"It was a picture perfect launch of the largest rocket to ever (launch) from the west coast of the U.S. It just doesn't get any better!" a United Launch Alliance spokesman said in a statement.
Analysts say the 235-foot rocket is thought to be carrying a top-secret spy satellite for the National Reconnaissance Office, the federal umbrella agency that operates spy satellites.