"Your basic interplanetary drive, allows you to leave your planet's orbit."
It has to be purchased at your own empire, and the cost of the Drive is usually added onto your budget before you buy it so that you still have §100,000 when you go into space. However, the Gentle Generalist ability makes the Drive cost less, so you actually gain money when you have to buy it.
This tool can be purchased in the following locations:
Your Empire : §10,000