Location: Rogue Eye / Power Dome
After returning from the Landing Zone and Lunar Base, Rhea-6 will ask you to get a power gem for her light. To do this, warp to the Power Dome and enter the main shaft. Go down until you get to the second door on the left. This will be the location, or one of them rather, where you can get the power gem being requested. Headland on one of the occupied robot bodies and then go back up to the mid-range zap to return to the Waste Carousel. Rhea-6 will request that you "extract" the gem and put it up in her light for her. Doing so will earn you some upgrade points and this trophy.