NEW YORK — Natasha Henstridge, who began her movie career as the lead character in “Species,” is back in macho sci-fi action form as the star of the John Carpenter-directed “The Ghost of Mars,” replacing Courtney Love as a tough leader of a search team that comes upon a planet inhabited by ghosts. The film is being distributed by Screen Gems.Henstridge had been set to play the title character in “The Judith Exner Story,” a Showtime biopic about the woman who long maintained she’d had an affair with John F. Kennedy. Henstridge then got the offer from Carpenter to join a cast that includes Ice Cube and Jason Statham, and Sony worked out an arrangement so that Henstridge could be in the sci-fi pic, which began shooting this week. Once it wraps, she will return to the Showtime production. The actress has been on a roll. She starred in the modest hit “The Whole Nine Yards,” and recently completed “Second Skin,” co-starring Angus MacFadyen and directed by Darrell Roodt (“Sarafina!”). Other recent projects include “Kevin of the North,” with Skeet Ulrich and Leslie Nielsen, and the Don Roos-directed “Bounce,” with Ben Affleck and Gwyneth Paltrow. She’s repped by William Morris and managed by Ted Schachter.