Mariner 9, the first spacecraft to successfully go into orbit around Mars launched on May 30, 1971, and arrived November 13, 1971 for a duration of 167 days. This is the same pattern that has held up for more almost 50 years of Mars exploration: approximately 150-300 days.
Enigma was invented by the German engineer Arthur Scherbius at the end of World War I. Early models were used commercially from the early 1920s, and adopted by military and government services of several countries, most notably Nazi Germany before and during World War II.
The Enigma machine, a cryptographic toll introduced in 1944 & used in WW2, encrypted messages by replacing characters for plain text. Which type of cipher does the Enigma machine use? Substitution