Eventually I'll complete my study of the Church Fathers, who were grossly misrepresented and distorted by Dr. Sungenis (applying his own "eisegesis" to them), but by and large when they refer to a "sphere", they're almost always clearly talking about the shape of the entire world, including the firmament.
This idea that they believed in a ball-shaped earth that people walked on as it floated through space is absurd, and we can't read the "NASA ball" into every reference to a sphere (and even once time a circle), as Sungenis does.
What is clear is that they all universally believed in a solid firmament and that it was solid enough to hold real physical waters from the face of the earth. There were debates (some recounted by St. Augustine) regarding the shape of this firmament. There were debates (recounted by another Father, whose name slips my recall right now) about what it was made of, i.e. how the heavenly luminaries move if the firmament is solid enough to keep water out. Some argued that the heavenly bodies to not move within the firmament (since it's solid) but that the entire firmament rotates, others that it was made of some substance in between solid and liquid (perhaps like a plasma) where things could move through it, even though it was solid enough to keep waters out. We also have to recall that they did not have a concept of "gravity", so the notion of things sticking to the bottom of something would be strange and bizarre. In fact, some of the Father who believed the world to be shaped like a hemisphere believed that because they felt that the heavier elements would sink to the bottom of the cosmic water, while St. Ambrose made a case for how it might be suspended amid the waters. So they understood density, not gravity. St. Augustine chimed in by saying it would be acceptable to hold that the earth was at the bottom center of the cosmos (and therefore shaped like a hemisphere), since bottom center is still center.
So this idea of a ball floating around the vacuum of space at no point entered the minds of any Church Fathers, despite the fact that some try to read it into them.