Hi Chris - An RTL dongle and a modest antenna are part of our goals but we are not there just yet. Right now, we are broadcasting from GEO satellites in the Ku band (specifically from Galaxy 19 at 97W and from Hotbird at 13E). So the setup you'll need is a dish (with LNB), a DVB-S decoder and a Raspberry Pi to store the transmitted files. There is some discussion about putting together receivers on the Outernet discussion board.
But we are trying to move quickly to using certain existing LEO satellites, so something that can be received by an RTL is definitely in the works. Stay tuned.