Weirdly there are solid fuel rockets that can be turned on and off. Electric solid propellants (ESPs) is the term apparently. I saw youtube video where some g

Weirdly there are solid fuel rockets that can be turned on and off. Electric solid propellants (ESPs) is the term apparently. I saw youtube video where some guy was fooling around with the some brand or another of this type. see https://ntrs.nasa.gov/api/citations/20190030421/downloads/20190030421.pdf https://ntrs.nasa.gov/api/citations/20190030421/downloads/20...