This is SO fun! You have the foundation for a cool voxel-y interplanetary game if that's your jam. I had fun "getting into orbit" and watching my velocity increase at periapsis and decrease at apoapsis, then descending and landing with the rocket power button ([Space]). I would love a Minecraft + Kerbal Space Program fusion game and most of the pieces for it are already here. :D
> I would love a Minecraft + Kerbal Space Program fusion game
You might like Space Engineers.
Unfortunately Space Engineers is full of jank and random things will explode through no fault of your own. Actually, I guess that's on par with Kerbal Space Program-y. Also, Space Engineers will sometimes crash to desktop.
There's a Space Engineers 2 in development and I have good hopes for it.