Mercury-Redstone
The Mercury-Redstone Launch Vehicle, designed for NASA's Project Mercury, was the first American crewed space booster. It was used for six sub-orbital Mercury flights from 1960–61; culminating with the launch of the first, and 11 weeks later, the second American (and the second and third humans) in space. The four subsequent Mercury human spaceflights used the more powerful Atlas booster to enter low Earth orbit.
Missions: 6
Successes: 5
Partial Failures: 0
Failures: 1
Success Streak: 5
Success Rate: 83.3%