The Federal Aviation Administration has issued a sharp warning that rocket launches could “significantly reduce safety” for airplanes, urging pilots to prepare for the possibility that “catastrophic failures” could create dangerous debris fields. The official notice, known as a safety alert for operators, was dated Jan. 8, the same day that ProPublica published an investigation showing how pilots scrambled to avoid debris after two SpaceX Starship megarockets exploded over busy airspace last year.