I wonder why there aren't any missions to go to Saturn's moons for raw materials. Iapetus is basically a sphere made of ice and has an orbital velocity as low a

I wonder why there aren't any missions to go to Saturn's moons for raw materials. Iapetus is basically a sphere made of ice and has an orbital velocity as low as 3.26km/s and 2% of earths gravity. I don't know anything about its solar resources but a large scale RTG should be enough to kickstart the industry.