1973: Mars 4
In the early 1970s, the USSR peppered Mars with a slew of modules and landers. Both natural and human-made troubles plagued these craft, and Mars 4 (of 7) was no exception. A computer chip in the orbiter degraded on the way to Mars, meaning the relevant rockets didn’t fire when they were supposed to as the vehicle approached the planet. Instead of slowing down to enter orbit, Mars 4 sped right on by. Oops.
