FALCON 9 — NATIONAL (FR) 04.05.2021

GEIPAN received many reports from several French departments and regions of an unusual phenomenon around 22:55 on 4 May 2021. In a clear night sky, witnesses described a halo, cloud, bar or points of white/yellow light moving silently from northwest to southeast. This nationwide case was investigated in June 2021 and initially published as class B: a strong probability of an event involving Falcon 9 during the 25th Starlink satellite launch. Similar observations in subsequent months led to further investigations involving launch-vehicle specialists and CNES's operational space-surveillance service; see the investigation note. GEIPAN gives the following explanations for the 4 May observations. A luminous or fading ball, or halo, was a bubble of gas expelled over no more than a few seconds, illuminated by the Sun and visible through scattered sunlight against a dark sky, with the Sun having recently set for ground observers. A butterfly shape came from symmetric venting of gases, possibly including gaseous propellants, from the tanks. A bright point at the butterfly's centre marked the region where the gases had not yet dispersed; the source refers to diagrams for these 2 features. A succession of points was the still-grouped Starlink satellites. The case, initially B, was subsequently conclusively identified and reclassified A: observation of the restart of Falcon 9's second-stage engine and the Starlink satellite train from the same launch.