On this day in 1963, Joseph A. Walker flew a North American X-15 rocket plane to an altitude of 106,010 meters (347,800 feet) on X-15 Flight 90. His flight surpassed the so-called Karman line that’s 100 kilometers (around 62 miles) above Earth, which is recognized by international aviation and aerospace federations as the boundary of Earth’s atmosphere and the beginning of space. A month later, Walker again surpassed the Karman line in X-15 Flight 91, making him the first person to enter space twice.
NCPA
