This is a paid asset, but now you can download TK – Astronaut Free.
Detail this asset from Unity Store: Original Link
TK – Astronaut v1.0
Full Riged Astronaut Model HQ Textures 2048 x 2048 Base Normal Map Specular AO Full Riged Astronaut Model HQ Textures 2048 x 2048 Base Normal Map Specular AO Full Riged Astronaut Model HQ Textures 2048 x 2048 Base Normal Map Specular AO