No, not really. It's unusual to say "Success!" or "Victory!" or similar single word as an encouragement. There are a host of short phrases used for this purpose - the most common are "Good luck," "Go get 'em" (often competitive context) "Kick butt," "Knock 'em dead" (often performance context), "Break a leg" (almost always acting context), "Best wishes" (usually in a letter), etc. There's a long tail of "validation" type phrases ("You can do it!") that appear on refrigerator magnets everywhere.
"Godspeed" has fallen out of vogue since there's those who don't believe in God, but I know of no one who seriously objects to "Good luck" as a saying. There's always someone with a pet philosophy and chip on their shoulder out there on the Interwebs, but in general "good luck" goes completely unremarked among 99.99% of Americans, even if they would describe themselves as not believing in luck in a rational sense, just as "Goodbye" (orig. from "God Be With You") is used by even the staunchest atheists. The only retort to "Good luck" heard fits under the category of general boasting, e.g. "I don't need luck when I'm this good!" But that's not a serious objection to use of the term, in fact that type usually appreciates having the opening to beat their chest.