I don't know what tech No Man's Sky is using, but Voxel Farm[0] does something very similar (it's being used in Everquest Next and StarForge among other things). However, instead of marching cubes it uses dual contouring which produces nicer results. Also, it was made by one guy. His blog is amazing: http://procworld.blogspot.com/
[0]http://voxelfarm.com/vfweb/index.html