Background
Chalin grew up in a wealthy family on Chad III. After a devastating storm swept through their home, destroying the speeder bike Chalin was trying to make from discarded ship parts
he realised three things:
1. He hated water
2. He loved working on technology, ships, weapons, speeders, anything.
3. Living on a low tech backwater in the outer rim that is more than 75% water was not good for either of those.
So he ran away, heading for one of the nearby human settlements. Once there he organised passage on one of the supply ships, and found himself taken to Mandalore, the nearest political power, just along the Hydian Way.
Once there he began to search for work, war found that the Mandalorian military was exactly what he wanted, they had the best ships, fanciest gear, and most interesting weapons, and they were always looking for more skilled mechanics.
Chalin quickly found himself assigned to a small warship, about the size of a freighter, that was tasked with taking down a traitor hiding out in the Southern Rim.
In the battle that followed, their ship's hyper drive was almost totally destroyed, and their sublight engines crippled. Try as he might, Chalin was unable to repair either and the ship was forced to make a crash landing on the nearest planet. Most of the crew were killed or incapacitated on impact.
But by some miracle, Chalin was able to be survive, though not without serious injuries.
Taking what resources he could, including the captain's signature pistol, Chalin set out to find help.
Now, months later Chalin is finally healed from his injuries, and has managed to reach the largest port on Socorro. Determined to find a new crew, return to Mandalore, and hopefully earn enough credits to pay for his failures.
Motivation
Chalin really only wants four things
1. Good friends
2. Good tech to play with
3. To avoid water
4. To one day be able to fly and be in charge of his own heavily modified ship.
He's long since realised that adventure is the best way to get the first two, as difficult challenges build the strongest bonds, and tend to yield the best tech as rewards.
But for the last one, he's going to have to wait a long time. Because whether it's as the captain of a freighter, or squadron leader of seems starfighters, he's going to need a lot more credits, experience, and respect, before he can get that.