Astronauta vs. cosmonauta

The Spanish words 'astronauta' and 'cosmonauta' both refer to individuals who travel into outer space. However, they are used in different contexts and origins.

Astronauta

This word is commonly used in Western countries and comes from the Greek words 'astro' (star) and 'nauta' (sailor). It refers to someone who travels or works in space, typically associated with NASA and other Western space agencies.
La NASA envió a la astronauta a la Estación Espacial Internacional.
(NASA sent the astronaut to the International Space Station.)
El sueño de muchos niños es convertirse en astronautas.
(The dream of many children is to become astronauts.)
La astronauta completó una caminata espacial de seis horas.
(The astronaut completed a six-hour spacewalk.)

Cosmonauta

This term is used primarily in Russia and other former Soviet Union countries. It comes from the Greek words 'cosmo' (universe) and 'nauta' (sailor). It refers to someone who travels or works in space, typically associated with the Russian space program.
Yuri Gagarin fue el primer cosmonauta en orbitar la Tierra.
(Yuri Gagarin was the first cosmonaut to orbit Earth.)
La cosmonauta realizó múltiples misiones espaciales durante su carrera.
(The cosmonaut carried out multiple space missions during her career.)
El entrenamiento de los cosmonautas es extremadamente riguroso.
(The training of cosmonauts is extremely rigorous.)

Summary

In summary, although 'astronauta' and 'cosmonauta' both describe individuals who travel into outer space, their usage depends on the cultural and historical context. 'Astronauta' is commonly used in Western countries, whereas 'cosmonauta' is used mainly in Russia and former Soviet states.