Medical implants and spacecraft can suddenly go dead, often for the same reason: cracks in ceramic capacitors, devices that store electric charge in electronic circuits. These cracks, at first harmless and often hidden, can start conducting electricity, depleting batteries or shorting out the electronics.Now, after years of effort by manufacturers and researchers, the National Institute of Standards and Technology (NIST) and collaborators have demonstrated a nondestructive approach for detecting cracks in ceramic capacitors before they go bad.