Is there such thing as a solid fuel aerospike? I'd think the spike geometry would still give ambient (maximally efficient) expansion over a range of altitudes

Is there such thing as a solid fuel aerospike? I'd think the spike geometry would still give ambient (maximally efficient) expansion over a range of altitudes but IDK how they'd make that work with solid propellants. I'm sure the students didn't because it's never been done before, and you get an A for succeeding with proven technologies, not failing with unproven ones.