The Mercury-Redstone program consisted of three main missions, the pad abort, in-flight abort, and finally the actual spaceflight missions. the pad abort tested the capabilities of the launch escape system while the vehicle was on the launch pad. The in-flight abort test was similar in natural except it was during a simulated ascent instead of on the pad. Finally you had the actual suborbital spaceflights, each one going up and quickly coming back down.