The window is not a green screen, that is Earth, and his face carries the disbelief for you. Almost nobody gets this trip, so a real photo from inside the capsule is the whole argument. The title just confirms it really happened.
How the packaging works
Title
The title states the unbelievable trip in plain words.
Thumbnail
The capsule shot with Earth in the window proves the trip is real.
Remix this
When you get access to somewhere viewers cannot go, let one real photo from inside do the selling. Skip the text, the location plus a genuine reaction beats any caption.