His Divine Grace A. C. Bhaktivedanta Swami Prabhupada says if you go up you see Earth as a global sphere and only on the ground do you see it as flat. (lecture in New York City 1966)

We can clearly see Earth is a globe today. Prabhupada says if you go up you see Earth as a globe but only on the ground you will see it as flat.(lecture in New York City 1966)

Of course man cannot enter the subtle heavenly world of Chandraloke in their gross material bodies and spacecrafts as Prabhupada always said.

Also regarding the word Dvipa and it's meaning that Prabhupada explains clearly-

"Dvīpa has two meanings "island" or "continent" and "planetary globes" situated in the ocean of outer space".

Srila Prabhupada - "The planets are called dvīpas. Outer space is like an ocean of air. Just as there are islands in the watery ocean, these planets in the ocean of space are called dvīpas, or islands in outer space" (Chaitanya Caritamrita Madhya 20.218, Purport)

Everyone should learn to read Prabhupada's books!!

Even Wikipedia quotes Prabhupada explaining that Dvipa means planetary globes in outer space. https://en.wikipedia.org/wiki/Dvipa