Terminator Salvation

McG signed on to direct as the first two films were among his favorites, and he had even cast Robert Patrick (who played the T-1000) in his films. Though he was initially unsure about ``flogging a dead horse,'' he felt the post-apocalyptic setting allowed the film to be different enough so as not to be just an inferior sequel. The idea that events in Terminator 2: Judgment Day and Terminator 3: Rise of the Machines altered the future allowed them to be flexible with their presentation of the futuristic world. McG met with the series' co-creator James Cameron, and, although he neither blessed nor denigrated the project, Cameron told the new director he had faced a similar challenge when following Ridley Scott's Alien with Aliens. He maintained two elements of the previous films; that John is an outsider to the authorities, and someone of future importance is being protected, and in this film, it is Kyle Reese.

Question: is terminator salvation a prequel to the terminator
Answer: no