Meaning: The astronauts are saying goodbye to the people on Earth.
Choice of Words: Astronauts are people who travel in space. They wave to say goodbye.
Alternative Expressions
Space travelers wave from portal.
Meaning: This sentence also describes astronauts waving from a window, but it uses different words to make it sound more exciting.
Choice of Words:Space travelers is another way to say astronauts. Portal is a fancy word for a window or door, especially one that leads to another world or dimension. When you put these words together, you get a sentence that is similar to the first one, but it uses different words to describe the same thing.
Star voyagers wave from viewport.
Meaning: This sentence is the most poetic way to describe astronauts waving from a window, and it uses words that are not as common as the other two sentences.
Choice of Words:Star voyagers is a poetic way to say astronauts. Viewport is a window on a spacecraft or aircraft. When you put these words together, you get a sentence that is even more poetic than the second one, and it still describes the same thing.