We live in a firmament, if they were able to leave the firmament, the billionaires would have been gone already plus it tells us in the Bible.

Genesis

And God made the firmament, and divided the waters which were under the firmament from the waters which were above the firmament; and it was so.

8 And God called the firmament Heaven. And the evening and the morning were the second day.

9 And God said, “Let the waters under the heaven be gathered together unto one place, and let the dry land appear”; and it was so.