Complete the frustrated spaceship mechanic's log entry.

The core reactor is completely fried. It's no use _______ to patch a level-five breach with galactic duct tape; we need a brand-new engine.

The correct answer is trying.

The expression "it's no use" is always followed directly by a gerund (the -ing form of a verb). We do not use the infinitive ("to try") or add prepositions like "in" after "use."