 mercury-redstone bd was an unmanned booster development flight in the u.s. mercury program. it was launched on march 24, 1961 from launch complex 5 at cape canaveral, florida. the mission used a boilerplate mercury spacecraft and redstone mrlv-5. after the problems that developed during the mr-2 mission carrying the chimpanzee ham, it was apparent that the redstone needed further development before it could be trusted to carry a human passenger. dr. wernher von braun added mercury-redstone bd (booster development) to the launch schedule between the mr-2 and mr-3 missions. the cause of previous redstone rocket over-accelerations was a servo valve that did not properly regulate the flow of hydrogen peroxide to the steam generator. this in turn overpowered the fuel pumps. the thrust regulator and velocity integrator were modified on the mr-bd and later mercury-redstone rockets to prevent them from exceeding the speed limit again. another problem encountered in previous mercury-redstone flights were harmonic vibrations induced by aerodynamic stress in the topmost section of the elongated redstone. to fix this problem, four stiffeners were added to the ballast section and 210 pounds (95&nbsp;kg) of insulation was applied to the inner skin of the upper part of the mercury redstone instrument compartment. the mission used a boilerplate mercury spacecraft, with in
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