Find The VEU Droid

Test Chamber 13: Place portals as shown in the image. Use a portal to move the laser sideways and a time portal to send it into the future. You may take damage from the laser to travel into the future. Once in the future, rearrange portals so the laser hits the target. Exit through the door.

Test Chamber 14: Travel to the present using a time portal. Summon a reflector cube and position it in the present as shown. Use a portal to bring a laser through the first node, then reflect it into the next two nodes. Travel to the future. Use portals to bring a laser into the present through the time portal, ensuring it passes through the node. Retrieve the reflector cube from the future and bring it to the present via a time portal. Ensure the present reflector cube hits all three nodes; adjust as necessary. Return to the future to retrieve the future reflector cube if moved. Place the future reflector cube at the end of the nodes to reflect the laser into the receiver, completing the chamber.

Test Chamber 15: Go through the particle field to the left. Place a portal where the laser hits the wall and a time portal on the opposite wall. Travel through the time portal to the future to bypass the particle field. Head to the other side of the room and use another time portal to return to the present, now on the other side of the particle field. Place a new portal on the upper wall to direct the laser to the first receiver. Travel to the future and place a portal on the small wall in the laser room to aim at the receiver. Return to the present; the laser should be hitting the first receiver, powering an elevating platform. Stand on the platform and shoot a time portal behind the node to raise the platform further, allowing you to summon a reflector cube. Place this reflector cube on the lip above the second receiver. Travel to the future. Pick up the future reflector cube and run into the laser room. Place a time portal to bring the future reflector cube into the present laser room, positioned to reflect the laser into the second receiver through the node. To reach the other side of the particle field without going through it, use a portal on the other side or a time portal. You need to be in the present on the other side. Climb the stairs and use a portal on the upper wall to hit the third receiver. Move the reflector cube onto the switch to complete the chamber.