How do you unlock and craft backpack and jetpack?

[Zuleica]

And the other armor slots?

[rphillips1986]

Your jetpack is part of the suit you're already wearing. Press [J] to turn it on. Space bar to use it. On planets it works to give you a large boost to get over large obstacles or cover a large distance. You can't fly with it. And I guess [Tab] would be your backpack.

As for the slots in your menue for upgraded suit features those haven't come yet.