The laser system for BELLA, the Berkeley Lab Laser Accelerator, has delivered a petawatt of power — a quadrillion watts — in a pulse just 40 femtoseconds long — a quadrillionth of a second — at one pulse per second. No other laser system has achieved this peak power at this pulse rate. BELLA’s laser should soon be driving electron beams to 10-billion-electron-volt energies in an accelerator just one meter long.