The launch on Wednesday of a Delta IV Heavy rocket will be powered by engines made in the San Fernando Valley. The three hydrogen-burning RS-68 engines on the rocket were manufactured by Aerojet-Rocketdyne at its Canoga Park plant, as were the upper-stage engine and multiple altitude control thrusters. Aerojet-Rocketdyne is owned by GenCorp Inc. in Sacramento. The launch of the Delta IV Heavy rocket from Vandenberg Air Force Base, north of Santa Barbara, will be the eighth this year by the United Launch Alliance, a joint venture of Lockheed Martin and Boeing Co. The Delta IV Heavy is the largest rocket in the U.S. and uses two strap-on liquid rocket boosters in addition to its common booster core. It is reported to generate 17 million horsepower. The rocket will carry a classified spacecraft for the National Reconnaissance Office.