View of one of the Solid Rocket Booster (SRB) Holddown Studs and Frangible Nuts, minus the Blast Can (which captures the Nut pieces during liftoff). The Holddown Studs (4 per SRB and each about 3 ft long) mount the Shuttle vehicle to the Mobile Launcher Platform (MLP). At T-0, a pyrotechnic in the Frangible Nut fires and splits the Nut into two pieces, releasing the vehicle for flight. The two halves of the Frangible Nut are captured in the Blast Can (not seen) and fly along with the Booster. The Stud and bottom Nut fall into a sand pit in the MLP.