I'm sorry for you Space pilot .
I supposed you tried restarting the game?
I'm afraid your blueprint is lost indeed, but for your world maybe you can reload a previous save...
Hopefully you manage to get it all back. I've had similar things happen, and it's not fun. One word of advice I can give for the future is to take screenshots of your builds. It's what I have done, and while it's not as elegant as backing up the files, it still manages to get the job done (especially on iOS).