As neschof says above, the sky is gorgeous. it's very billowy and snow-filled. Lovely!!
I wonder if the tracks themselves need some more definition? Like, maybe some debris or snow mounds with shadows? They seem very soft and gentle, but usually tracks in the snow aren't quite so consistently clean. I get that the snow has been swirling and maybe covered up some of the raw broken snow, but I wonder if maybe it might be interesting to add it back in... Your earlier version where you ran over the tree suggested a bit of chunkiness or density to the snow. Maybe incorporate some of that? I think what I'm personally missing is a sense of edges.
Your instinct to add more shadows and deeper values is good! It made things a lot deeper and richer. I'd keep going with that. There is something interesting about "whiteout" conditions created by blustering snow, and I can see how that might narrow the value range of everything into a lot of subtle greys, but maybe a couple layers of flurries behind and in front of the spaceman might help to communicate the depth and scale you're wanting to suggest? That way you can up the whites and deepen the darks in the snow, and the snow floating on top will contrast against them?
I dunno--just my 2¢. It's coming along!!!! I love love love the cold, hard blues you've chosen. They're very chilly! And the subtle pale blues of the snow is very delicate! Well done!!