Talk:Warframes/@comment-72.129.144.6-20130130195955/@comment-5983359-20130130204704

You need to craft the helmet, chassis and system before being able to craft Frost. The blueprints for all three is dropped from a boss (I'm not sure who, but its either Ceres or Eris boss).

Crafting helmet, chassis and system requires 12 hours. After crafting all three, then you can craft Frost, which requires 3 days.