Orwell Astronomical Society (Ipswich)
Falcon 9 Propellant Dump, 24 March 2025
On 24 March 2025, a spent Falcon 9 second stage vented propellant to reduce pressure in the fuel tank prior to a forced re-entry into the Earth's atmosphere at around 20:50 UT over the Indian Ocean. (The reduction in pressure was to prevent the tank breaking up and creating more space junk.) The stage was tumbling and the vented propellant ultimately had the appearance of a large, light blue, spiral galaxy! The event was widely visible over the UK.
The rocket stage was launched by the National Reconnaissance Office from Florida at 17:48 UT on 24 March. The orbit of the payload was unpublished.
The phenomenon was in continuous view of at least one of my sky cameras. The following video provides a common timeline (in UT), switching between three cameras to provide the best view. The video has been reduced from 1080p to 720p and sped up by x10. The phenomenon appears low in the bottom left over a neighbouring property. An assortment of aircraft rush by. Cassiopeia is to the upper left and Polaris at top right. At 17 s, there is a discharge, followed by another at 38 s, followed by a change of camera at 41 s. The rocket stage tumbles while venting, creating an impressive spiral pattern. There is another change of camera at 56 s. Venting continues to be visible until the craft enters the Earth's shadow.
The following two images are a compilation of stills from the video.
Nigel Evans