I got back home 48 AU!
No idea if it's a lot or not. But it is an amount.
The gameplay is strangely soothing.
Venus seems to be very barren. Throughout my playthrough I found only 3 resource sites, and I dropped dozens of probe drones. Maybe the protagonist should be searching for gold on another planet.
Also, if the extraction drones don't find anything, they just self-destruct, and you can't collect them. I know this is so that the player has to pay in fuel to search the area, but I once I dropped an extraction drone a little but too far from the probe drone, and lost all my precious iron needed to build one. Maybe just not let players drop extraction drones in unprobed areas instead?
One more thing. The hint tells us to explore while the probe drone is scanning, but it makes no sense to do so. You can only have one dropped probe drone. And it is very foolish to risk extraction drone self-destruct by dropping it in a not scanned area. So the best course of action is to wait for the probe drone to finish (and maybe try to catch some debree)