5 years, 2 months ago
In this picture from the AsiaSat 6 launch by Falcon 9 on 8th September 2014, the part of the rocket between the fairing and the engine appears to be surrounded by dust, water droplets or debris:
And another launch:
There is smoke but many fewer particles in launches of other rockets. Saturn V:
These particles are particularly prominent in Falcon 9. What are they?
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Ice. All these rockets use oxygen as the oxidizer component of their propellant. The Saturn 5 also used hydrogen in some of its engines (upper stages). They are stored in liquid state, which requires very low temperatures (below -183c for oxygen, below -253c for hydrogen). Despite insulation, some of the outside surfaces can get cold enough to condense and freeze moisture out of the air, so there will be accumulations of ice. When the vehicle launches, acceleration and vibration shakes it loose so it falls away.
answered Nov 9 ’14 at 19:54
Anthony XAnthony X
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