That’s usually the major drawback to solid rockets.
(Apologies if that’s obvious)
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/20...
https://www.youtube.com/watch?v=eHRyv7ARb5M
That’s usually the major drawback to solid rockets.
(Apologies if that’s obvious)