Mark's Almanac for July 19, 2021
It was on this date in 1977 that Rockwell Collins received the world's first GPS satellite signal. It laid the major groundwork for the technology we use today. And it was on this date in 1985 that teacher Sharon Christa McAuliffe was chosen to become the first private citizen in space. Sadly, the space shuttle Challenger exploded shortly after liftoff in January of 1986, killing all on board including McAuliffe.