ABSTRACT
The booster that failed is one of two solid-fuel boosters designed to help the shuttle reach the velocity needed for orbit (see Figure 4.1). The booster is shipped to the launch site in sections and is assembled onsite. The aft field joint is one of the joints made during the fmal field assembly. The solid propellant, cast inside the booster, burns from the center outward. The burning fuel expands, causing
great pressure inside the booster and giving the booster its thrust. Essentially the booster is a thin-walled, large-diameter pressure vessel. As the fuel is burned, the temperature of the outer wall and the joint also increase.
