After talking to Vehn Terev as part of the Priority Op Hunting the Archon, and leaving Kadara Port once, use the docking controls to go down to Kadara Slums. Enter the bar Tartarus, go to the second floor, and out onto the balcony. Talk to the disillusioned outlaw leaning against the wall to the immediate left. She offers to show you how Outlaw tech and materials works. Use any Research Station, on the docks at Kadara Port or on the Tempest, to craft one of three Outlaw weapons, the Sandstorm, Sidewinder, or Vanquisher.