In 1963, Captain Engle was assigned as one of two Air Force test pilots to fly the X-15 Research Rocket aircraft. In 1965, he flew the X-15 to an altitude of 280,600 feet, and became the youngest pilot ever to qualify as an astronaut. Three of his sixteen flights in the X-15 exceeded the 50-mile (264,000 feet) altitude required for astronaut rating.
NASA
Former NASA astronaut Joe Engle poses in front of an X-15 plane in this Dec. 2, 1965, photo. On June 29, 1965, Engle flew the X-15 to 280,600 feet, becoming the youngest U.S. pilot to qualify as an astronaut.
The Kansas native flew the X-15 for the U.S. Air Force 16 times from 1963 to 1965. Three times Engle flew an X-15 higher than 50 miles (the altitude required for astronaut rating), officially qualifying him for Air Force astronaut wings and providing him a brief moment for sightseeing at the edge of space.
“You could glance out and see the blackness of space above and the extremely bright Earth below. The horizon had the same bands of color you see from the shuttle, with black on top, then purple to deep indigo, then blues and whites,” he said.
Image credit: NASA
1963年，恩格尔上尉被任命为两名驾驶X-15研究火箭飞机的空军试飞员之一。1965年，他驾驶X-15飞至280,600英尺的高度，成为史上最年轻获得宇航员资格的飞行员。在他驾驶X-15的16次飞行中，有三次飞行高度超过50英里（264,000英尺），达到宇航员评级所需的标准。
NASA
在这张摄于1965年12月2日的照片中，前NASA宇航员乔·恩格尔站在一架X-15飞机前。1965年6月29日，恩格尔驾驶X-15飞至280,600英尺，成为美国最年轻获得宇航员资格的飞行员。
这位堪萨斯州人从1963年至1965年为美国空军驾驶X-15进行了16次飞行。其中有三次，恩格尔驾驶X-15的飞行高度超过50英里（宇航员评级所需的高度），因此正式获得了空军宇航员徽章，并短暂领略了太空边缘的景色。
“你可以瞥见上方漆黑的太空和下方极其明亮的地球。地平线上呈现出与航天飞机上所见相同的色带：最上面是黑色，然后是紫色到深靛蓝，接着是蓝色和白色。”他说。
图片来源：NASA
