cool article on the history of the first American rocket to reach outer space, the Bumper 5 (the previous 4 Bumpers failed for various reasons).
The first US rocket to reach outer space was launched from White Sands Proving Ground in New Mexico on February 24, 1949. It flew to an altitude of 244 miles, high above the 62-mile Karman line that divides Earth’s atmosphere and space.
Known as Bumper 5, it was a two-stage rocket that combined a German V-2 rocket with a WAC Corporal sounding rocket. The V-2 achieved its great thrust by burning a mixture of liquid oxygen and alcohol at a rate of about one ton every seven seconds, and the WAC Corporal was a hypergolic liquid-fuel rocket.
In the Bumper rocket design, the powder rocket booster normally used to launch the WAC Corporal was left out to limit the size of the combination missile and to allow the smaller rocket to fit deeply into the V-2, with enough space in the instrument compartment of the V-2 for the guidance equipment, along with the guide-rails and expulsion cylinders used as a launcher for the WAC Corporal. These cylinders were activated by means of a compressed-air-bottle through a pressure reducer and a solenoid valve. The valve was activated by the final cut-off signal of the V-2, causing the fins of the WAC Corporal to slide out of the three slots in the upper part of the warhead launcher.