This may be changing with rapid extension of satellite size towards the small end of the spectrum. Small size is now significant. For example, a radar imaging

This may be changing with rapid extension of satellite size towards the small end of the spectrum. Small size is now significant. For example, a radar imaging constellation might consist of multiple transmit/receive satellites, each of which could be quite small (say, 1 - 5 cu. ft.). The X37B could accommodate that - especially after it snipped the solar panels off.