Nora Tallis is stranded on Elaaden until her shuttle is repaired. Retrieve her shuttle's thruster from the scavengers she sold it too.
When you approach the sinkholes northwest of Paradise the Nexus researcher Nora Tallis calls you over the comm asking for help. She is in one of the sinkholes. Talk to her to learn that she traded the shuttle's thruster for water when she was in a delirium because of lack of water.
You also learn that she has a theory about where the sinkholes come from.
She gave you the navpoint to the scavenger camp. The camp seems to be empty. You find two dead scavengers. They have been beaten to death. Inside the building is McCrone, who is hiding from a raider gang lead by Axius. They raid other scavengers camp, kill everyone and loot the camp. The took the thruster too. McCrone gives a navpoint.
After Axius and his gang have been eliminated you can fetch the thruster upstairs, and then return it to Nora.
It's possible to just run straight into Axius and get the thruster without ever talking to McCrone.