Lt. Quinn is the character you play as in Redshift. Quinn was young when his parents died in a battle. The Galactic Council took him in and gave him a place to stay. Quinn, overwhelmed with the generosity of the council, in-listed as soon as he could in their military. He rose through the ranks fast, and after many major battles he achived the rank of Lt.
The Admiral seeing great potential in Quinn started giving him more solo missions. These missions required much stealth, and just as much combat experience. Every mission that the Admiral gave to Quinn he exceeded and then some, so he was an obvious choice to send Quinn after Viper.