
There shouldn't be much litter resulting from space launches from the Moon for a few reasons
1: Single Stage To Orbit is the standard launch model from the surface of the moon. This means you don't need to throw away stages, fuel tanks, decouplers, o-rings and whatever.
2: Assuming we are going there to stay, we shan't be throwing bags of piss and shit away any more. That's all getting recycled.
3: Assuming reusability and environmentalism are here to stay, rockets will continue to be less wasteful - e.g. SpaceX's Falcon fairings are becoming increasingly reusable, and SpaceX's ITS/BFR/Starship system could even do away with a lot of the 'littering' that you see in falcon launches because they have cargo bays integrated with the 2nd stage, which will generally speaking return to Earth or stay put on the moon or Mars.
I'm with Zubrin - humans are the most profitable resource in the solar system.
But even if you're purely talking about precious metals, the moon is a barren desert compared to the asteroid belt. And if you only want fuel, the methane lakes of Titan are somewhat more appealing than the wisps of hydrogen found in lunar regolith.
( , Fri 3 Jul 2020, 21:48, Reply)

You assume that we won't be throwing bags of piss and shit away. But what about materials that aren't so readily recyclable? If launching rubbish into space was commercially viable, we'd already be doing it and reassuring the people of Earth that it'll all burn up when it hits the Sun. On the Moon, launching our detritus into space might end up being a realistic prospect.
( , Fri 3 Jul 2020, 21:56, Reply)

To reach the sun, you'd need to cancel out all of Earth's orbital speed (averaging at 29.78 km/s that's a lot of delta-v), or utilise some clever cosmic billiards to reverse slingshot your velocity down low enough to spend the last of your fuel on the last few hundred m/s needed to deorbit into the sun. Not worth it, even if you could make fusion powered ships.
You could just launch your rubbish into a nice long suborbital ballistic trajectory and let it burn up like that. An incinerator would always be safer, and I expect a lot more efficient than using a Starship as a garbage scow.
( , Fri 3 Jul 2020, 22:19, Reply)