Chuck is in charge of having the necessary storable propellants available for facilities such as the shuttle launch pad, at Kennedy Space Center. The propellants must meet certain purity standards and quantity requirements, and be kept in containers that are not too difficult to use. Chuck is also required to know the needs of certain people or departments, and how to best address those needs. And now, here is Chuck Davis to answer your questions.
Solid fuel is a type of propellant.
Typically a rubbery material. Please, don't be bashful. Once the solid propellant is used up, the rocket is finished. The Shuttle's SRBs are the only solid rockets recovered, refueled, and re-used. I was answered a similar question since in the movie, Armeggedon, a shuttle must run down the asteroid.