On this day in 1975 – August 20th – NASA's Viking 1 was launched.
Viking 1 was the first of two spacecraft (along with Viking 2) sent to Mars as part of NASA's Viking program. A year after its launch it became the first spacecraft to land successfully on Mars and perform its mission
On this day in 1913 – August 31st – English radio astronomer Bernard Lovell was born.
Lovell was a pioneer of radio astronomy and founded the Jodrell Bank Observatory in Cheshire, England in 1945. When the telescope was built there - later named the Lovell Telescope - it was for many years the largest steerable radio telescope in the world.