Despite the success of "Alien", its sequel took years to develop; it was delayed by lawsuits, a lack of enthusiasm from 20th Century Fox, and repeated changes in management. Based on his scripts for "The Terminator" (1984) and "" (1985), Cameron was hired to write a story for "Aliens" in 1983. The project stalled again until new Fox executive Lawrence Gordon advocated a sequel. Although relatively inexperienced, Cameron was given the director role based on his success directing "The Terminator". On an approximately $18.5million budget, "Aliens" began principal photography in September 1985. Like its development, filming was tumultuous and rife with conflicts between Cameron and the British crew at Pinewood Studios. James Horner composed the film's score. The difficult shoot also affected Horner, who was given little time to record the music.