Reddit mentions of Mystic Universe: An Introduction to Vedic Cosmology

There's no one accepted position on cosmology in ISKCON yet. There's a book, however, that might unify all our divergent views and reconcile them with cosmology of Bhagavatam (one of our main doctrinal texts).

The universe that we see is only one part of the Vedic cosmos, the Sisumara system, and we see it because Sisumara acts as an interface in each and every interaction we have in this world, delivering us our karma and making things perceptible to us. This interface becomes perceptible, too, and, based on these perceptions, we construct our current "scientific" model of the solar system, stars, planets, Moon travel etc.

In Vedic sense, however, since all these perceptions are physical, we never ever leave our current level of existence, which is "Earth", and never ever reach the Moon level of existence, which is "mind", where there are neither senses nor sense objects. In that understanding we've never traveled to the Moon even if our physical experience shows that we had (or faked it, as some would argue).

Distances to the Sun or the Moon given in Bhagavatam are not physical but show the amount of transformations one needs to perform to change from, say "mind" level to "body" level of existence, like the amount of effort you need to transform your desires into reality, so to speak.

This explanation is based on the theory of Sankhya - one of the six traditional schools in Hinduism. Its practical application used to be yoga but since no one can do it properly anymore and resorts to stretching exercises instead, Sankhya has become largely forgotten. Turns out it can still be useful in describing Vedic cosmos.