India, June 9 -- Late-winter frost was in full spell when a sleepy Polish town woke up to mysterious fireballs lighting up the obsidian sky on a February night.

Neither Helios was on an errand, nor a mythical dragon was on a recce of the Polish skies that night. Experts confirmed the next day that those were the wrecks of the upper stage of Falcon 9's reusable launch vehicle that had failed to deorbit on time, malfunctioned, broke into pieces, and crashed down on earth like fireballs.

Elon Musk's SpaceX grounded Falcon 9 rockets multiple times last year following anomalies in the recovery of their second stage or upper stage. From a liquid oxygen leak to a malfunction while grounding, the company has faced multiple failures while bringi...