After having lived long -- a half century since it was conceived -- Star Trek is due to prosper like never before at the box office this weekend. J.J. Abrams's latest account of the voyage of the starship Enterprise, first chronicled by Gene Roddenberry in a 1964 pilot starring the late Jeffrey Hunter, is expected to earn more than $100 million in its opening weekend. Star Trek Into Darkness opened Thursday in 3,762 theaters and collected an estimated $13.5 million (including $3.5 million from Wednesday's IMAX screenings and midnight previews). The film opened in seven overseas markets last weekend and is due to add 33 more this weekend. Iron Man 3 is expected to take a big hit from the Star Trek opening, falling as much as 60 percent to around $30 million, according to forecasters. (Nevertheless, on Thursday it hit the $1-billion mark in total ticket sales, with $301.9 million domestically and $698.9 million internationally, according to Disney.) But The Great Gatsby is likely to survive the competition of the sci-fi combatants and come in with around $25-30 million, possible displacing Iron Man 3 as the runner-up. The competition becomes even more intense next weekend -- Memorial Day weekend -- as Fast and Furious 6, The Hangover 3 and Epic fight for box-office honors.