[floxy]

>you probably aren't going to get any advantage by trying to build one in Earth orbit.

People want to put a radio telescope on the far side of the moon, so that it doesn't have interference from terrestrial RF sources:

https://en.wikipedia.org/wiki/Lunar_Crater_Radio_Telescope

...and your spatial resolution is proportional to the size of your telescope. So you could have really high resolution if you speckled your interferometric telescope array units around L1, L2, L4, and L5.