Rocket

Rocket is an item dropped by Golem at a 100% chance. It allows you to leave the world you are in (however, if hovered, it says Earth (or if the world is named Terraland, Terraland)). It can be upgraded for 20 Adamantite/Titanium, 20 Cobalt/Palladium, 20 Mythril/Orichalcum, and 15 Wood. However, it can only be upgraded after defeating Golem, and a Pre-Golem world will prevent further upgrades, but will keep the current upgrade. Rockets can be used to travel for an indefinite time; no fuel. Although, Wood is used to "fuel" the rocket, it is indefinite. The costs for each upgrade item increase by 7 per upgrade.

A rocket can turn into a Frigate once it reaches the 7th upgrade in the Terrestrial Frontier. This however, takes 300 Titanium.