Tsar does not "literally" translate into king. The Russian word for King is Korol'. Tsar means Tsar, it's a specific title, and it's not even the direct translation of Emperor (which is Imperator), though it quickly became synonymous with the word Emperor as it implied equality with the title. It comes from the word Caesar.

Sputnik does not "literally" translate into satellite. The Russian word for satellite is Satelit (pronounced sat-eh-leet). Sputnik means "fellow traveler of the world". It has merely become synonymous with satellite since it was the first man-made satellite to successfully orbit the earth.

Cosmonaut means the same thing as Astronaut, but since their inception the terminology has purposefully been divided as an issue of national pride as well as differentiation between the two original space programs--Soviet vs American. Cosmonaut means sailor of the cosmos, while Astronaut means sailor of the stars. Russians preferred to call them space-men, Americans preferred to call them star-men. We called them their respective titles due to the space race--it was another way to make the two space programs distinct. The tradition has remained that way ever since.

Also important to note that China, India and even France have their own names for Astronauts as well.

"Cosmonaut" isn't the translation in Russian of Astronaut.

Both words are just etymologically linked to ancient greek. "Kosmos" meaning Universe, "Astron" meaning Stars and "nautis" for "sailor".

At the birth of their space program, Russians and Americans just happened to use different greek words to describe the same thing. Similarly the French used the greek word "Spatium" meaning Space, giving us Spationauts.

Here's a good video explaining it. https://www.youtube.com/watch?v=fQ9WtSnFzcY