Nathan moved to the control panel. His hands were steady, but his breathing wasn't. He initiated the full acceptance cycle, the exact same test sequence the Department of Defense used during qualification—the same test that 12 units had failed.
The SD9 powered up. The robotic arm lifted from its rest position, smooth and fluid: no stutter, no hesitation. It moved to the first weld point. The arc ignited, a clean blue-white flame that hissed against the test plate.
First cycle: the arm moved through its complete welding pattern. Every joint, every angle, every transition—smooth. The stress gauges on the monitoring screen showed green across the board. Operating temperature: stable.
Second cycle: identical, no deviation.
Five cycles, ten. The arm moved like water, precise, rhythmic, the way the engineers who originally designed it had intended.
Nathan pulled one of the completed test plates and carried it to the ultrasonic flaw detector in the QA station. He ran the probe across each weld joint. The screen showed clean signatures: no voids, no cracks, no inclusions.
"Joints are clean," he said, his voice cracking on the second word.
20 cycles; the machine didn't flinch.
Pemberton turned to the chief engineer standing behind him. "How many cycles did the failed units complete before seizing?"
The engineer checked his tablet. "Between 180 and 240."