Aerospace manufacturer Aerojet Rocketdyne is laying off 5 percent of its workforce including positions at it Chatsworth rocket engine plant, according to media reports published Friday. The exact number of employees losing jobs in the San Fernando Valley was not known but the total cuts between Chatsworth and Aerojet’s Sacramento facility were 225 positions, the Daily News reported. Rocketdyne was acquired in June by GenCorp., in Sacramento, which then combined it with the AeroJet-General Corp. subsidiary. Rocketdyne had been owned by United Technologies Corp., of Hartford, Conn. Rocketdyne has a long history in the Valley where it designed, developed and made the engines for the Saturn V rocket used in the Apollo program and the main engines for the Space Shuttle program. The Daily News quoted a letter from company President Warren M. Boley Jr. that the layoffs were necessary to eliminate redundancies and achieve efficiency from the Rocketdyne acquisition. The positions eliminated in Chatsworth include engineering, operations, supply chain and materiel management and business development. Rocketdyne last made staffing cuts in November 2012 when it eliminated 100 positions as a response to an uncertain future of the space industry and the general economic climate. The company did not return repeated calls for comment on Friday.