Helmet Challenge sketches

The Helmet Challenge has been an amazing viral illustration challenge, and I had to get involved. Here are two that i rendered from a sketch bank of about 3 dozen, so there may be more to come.
The white one is based off the idea that BNL from the Pixar movie Wall-E had Humans do the terrestrial exploration before they got fat and lazy and created the EVE unit to do the exploration.
The yellow one is based off a distant planetary race that needs these types of helmets to be able to breathe outside of enclosed quarters.