[defrost]

Sure .. from my PoV I can live with "powder" it's the "boom" that rankles.

Relatively slow controlled energy release for thrust isn't particularly evoked by the word BOOM!!

Otherwise simplifying rockets and missiles as they are today to tubes of slow release thrust (with some additional wrinkles such as side thrust | directional thrust to 'balance' load over thrust, multi stages, etc) seems innocent enough.