Has anyone watched the YouTube video of the test of the RS-25 engine ? There are two interesting observations. One, the cars that are parked in close proximity to the testing facility and two the large plume of vapor emanating from just above the ground in the foreground of the video. My guess is that NASA stores the liquid oxygen and hydrogen for these tests in underground tanks and the plume is caused by the ground above these tanks being chilled by the gases evaporating in these underground tanks.
Are there any other possible causes for the phenomena?
Are there any other possible causes for the phenomena?