Magnum was a class of SIGINT spy satellites reportedly operated by the National Reconnaissance Office for the United States Central Intelligence Agency. The program remains classified, and the information that exists is speculative. The Magnum satellites, built by TRW, are rumored to have large (estimated m (ft) diameter) umbrella-like reflecting dishes to collect RF signals from Earth. The Magnum/Orion satellites replaced the older Rhyolite/Aquacade series of SIGINT satellites, and have themselves been succeeded by the Mentor/Advanced Orion satellites.