Why would a moon telescope be desirable over a satellite telescope?
They want to build a radio telescope, not a simple optical telescope.
Coming back to the topic, I'd like to see the reasons why both approaches could be beneficial. I see, for example, that for space-based constructions we don't - mostly - have interference from the surface of anything, while for surface-based constructions we have support and resources. Do we have a full analysis which would allow us to say "surface always sux, in-space forewa" or "only l00mers build in space, real men are firmly grounded"? Or, talking about a finer point, deployment only - do we have full justification?
But it requires those different clusters of collectors to be stationary - so while you could probably build a swarm of satellites, they would have to stay in very precise distances from each other over time which would be considerably more difficult than planting them on a surface.
Also, a big shield like the moon blocking out radio interference coming from the earth is desirable.
IANAA, corrections to my understandings welcome
For optical frequencies, the phase is difficult to measure directly, so we instead polish the surfaces down to a fraction of the wavelength of light (so that it all has the same phase). For radio telescope, the frequency is a lot lower, and we actually can measure the phase directly, so we can make our sensors crazy shapes and adjust it by adding delay. If you can change the individual delays (say, via software) you can change how they interfere and therefore change the sensitive direction for your telescope. This is how phased arrays function.
Is this necessary, or do they simply need to precisely distinguish their relative position? My understanding of the JWT's not-perfectly-smooth lens is that the ability to measure (and correct for) its distortions vastly simplified the construction, and I naively think the same principle could be used in a swarm of satellites.
But it requires those different clusters of collectors to be stationary - so while you could probably build a swarm of satellites, they would have to stay in very precise distances from each other over time which would be considerably more difficult than planting them on a surface.
Even considering that the "surface" in question is the moon?
We know how to make thrusters. We don't know how to mine the moon and make a telescope from scratch.
In space, there are no rocks to mine, so you're have to launch all the material to space, which is wildly impractical/expensive.