科幻发射确认音

Compact sci-fi launch confirmation, 1800 ms. A deep 70 Hz ignition thump, then a rising three-note glass-and-steel chime (520, 660, 990 Hz) with a long clean ring on the last note, and a soft low rumble fading underneath. Cold, bright, earned. Dry, no reverb hall, no orchestra, no choir, no epic cinematic swell. Sustain the full stated duration.