Why didn't any space agency develop a radio astronomy telescope for space?
With the amount of SAR companies and new radio antenna satellites, it should be very cheap no?
Radio astronomy benefits from having very large antennas, which are difficult to package in a small spacecraft.
Most radio frequencies make it to the ground without atmospheric attenuation, which makes it less necessary to put a telescope in space.
The biggest benefit would be VLBI with a longer baseline.
"The biggest benefit would be VLBI with a longer baseline. "
This is what Queqiao is doing, or is intended to do, is it not?
Yes. AIU, RadioAstron also did some VLBI.