Where is the nanopack in ratchet and clank up your arsenal?

On Planet Zeldrin. You'll find it inside the destroyed ship (just before you Hypershot to the start of the in-game cutscene where Ratchet and Clank find the escape pod) you'll need to look to the right and you will see another hyper shot. Latch to it and jump across the gap. You will need the gravity boots, but as they're obtained during the storyline of the game, you will already have them.