1859
Birthday of Hugo Junkers, a German engineer and aircraft designer. He is generally credited with pioneering the design of all-metal airplanes and flying wings.
For further reading,
https://en.wikipedia.org/wiki/Hugo_Junkers
1984
Space Shuttle program: STS-41-B is launched using Space Shuttle Challenger. STS-41-B was the tenth NASA Space Shuttle mission and the fourth flight of the Space Shuttle Challenger. It was notable for including the first untethered spacewalk.
For further reading,