I think this one is the best non-romance drama of 2021.

The story revolves around sort of post apocalyptic world where water shortage has lead to it's commercialisation similar to cancer meds (maybe more chronic than it). To find new avenue of water countries are making ventures into outer space. Bae Doona and Gong Yoo are part of one of such mission.

The space station shown is very realistic. Side characters including Lee Joon don't shine that much. Their roles are rudimentary. Barring OST, everything else is perfect.