As you warp around the galaxy, typically five jumps, you will eventually come across a mission notice climbing a Freight is under attack by pirates. Kill all the Pirates attacking the Freight, which will cause you to be hailed by the Captain. Upon entering the Freighter, the Captain will offer the Freighter to you for free. While it is easy to jump the gun and accept this first Freighter, other players have noted that the second free Freighter you come across in this manner is always better. So you are advised to either request payment or decline the offer entirely.  Players have noticed it taking three hours before the Pirate Raids will happen again, so take the time to explore the new systems for resource-heavy planets as you continue charting the entire galaxy.  I have tested this and can attest to it working.