Travel to the Moon is not possible even today – because of the radiation. But is you look through a pair of binoculars at the right time, you can see the ISS in low Earth orbit.
Space travel within the Van Allen belt is a reality. And the Earth is round. AS I have flow to Asia and America – so gone all the way around.
The Flat Earth people need a trans global plane ticket. Stop off in Singapore and New York. You can see the curvature of the Earth, and have the time difference to cope with. Enjoy.