In recent years a new player in space launches has appeared, the SpaceX company and its Falcon-9 launch vehicle. As the flight rate increased, more and more ’space clouds’ were being generated by the upper stage, including thrust plumes and fuel dumps, sometimes under the unique twilight conditions that make them visible from the ground. Because SpaceX is a private corporation, the actual timing and physical nature of such events was rarely discussed either in advance or even afterwards, so it became an ‘attractive mystery’ for analysis by ground observers.
The value of such analysis was demonstrated on January 8, 2018 when a mysterious military mission, carrying a payload known only as ‘Zuma’, was conducted, and the results of the launch appeared to indicate a failure – or perhaps a camouflaged success.
BUT -- unexpectedly for SpaceX and its customer, some features of the second stage operation were serendipitously observed from the ground and from an airliner over Sudan in Africa. Those observations – and their potential implications – are discussed here:
Fortunately, a number of other second stage plume events had been noticed, before and after the Zuma event, for comparison:
Australia fuel vent spiral June 4, 2010
Indian Ocean fuel dump sphere Sep 29, 2013
Persian Gulf deorbit burn Feb 19, 2017
South African sighting of circularization burn Dec 23, 2017
Norway deorbit burn Feb 19, 2018
Post-GTO insertion fuel dump from Australia May 10, 2018 [WORKING DRAFT]
Now that the plume-generation procedures have been approximately displayed by such events, a more thorough search of all other SpaceX launches with determination of ground twilight zones that might have afforded visibility [weather permitting] ought to be made, followed by a search of both amateur astronomy websites and UFO blogs for potential reports.
On Feb 06, 2018, SpaceX launched its first Falcon-Heavy superbooster on a spectacularly successful debut. Due to a liftoff delay of several hours, the planned second firing of the upper stage for one minute to achieve a trans-Mars trajectory occurred south of California at local twilight. This created accidental viewing opportunities across California, Arizona, as far east as the Texas panhandle, and in northwestern Mexico. Those sightings, and on-board camera views of the second stage engine, provided enormously important new insights into the engine functions, as described here: