Portal/Chamber 17

The weighted companion cube
This is your introduction to the weighted companion cube. He will accompany you for the entire chamber, providing any assistance you require. When he drops from the transport tube, pick him up, and use him to climb the staircase.

You should now see a corridor with energy pellets bouncing back and forth - hold the cube in front of you to deflect the pellets harmlessly. After going through both corridor sides, you should reach the main test area where you need to raise three platforms, by bring pellets to the three receivers.

Platform 1
One of the platforms is easily opened without assistance from the cube. Place a portal within one of the two corridors, and the other on the ceiling above the angled wall. The pellet will bound and hit the receiver.

Platform 2
The doorway to the side contains a pellet launcher firing a pellet perpendicular to the receiver, but there is no method to place a portal. However, you can bounce the pellet using the cube into the receiver.

Platform 3
As with the first platform, use a pellet from the corridor, and place the other portal on the extruding wall.

To get the pellet into the receiver, you need to place the cube onto the raised button, and walk onto the other button as soon as the pellet passes by.

Exit
Once all three platforms are raised, shoot a portal onto the ceiling, and bring the cube with you. Jump across all three portals and onto the exit platform, and place the cube on the next button.

GlaDOS will explain that the cube has grown too intelligent and must be euthanized. Proceed into the open room and open the incinerator, and drop your companion cube into it. The chamberlock will then open.

Advanced
The weighted companion ball will assist you throughout the test.

- Or you can push down the first door button with the companion ball, and quickly let go of the button as it passes. Let it ping back and forth between the doors while you run behind the second door. Open that one with the companion ball.
 * The first catcher isn't much different, since you still poolshark the pellet off the angled wall. (The glass barrier isn't much of an obstruction.)
 * The second catcher has both buttons raised a bit higher. You need to knock down and stand on a camera to hold both buttons down.
 * The side catcher requires you to bounce the pellet above a glass barrier.

Portals
A 2 portal solution involves:


 * Place gold portal at the end of the first corridor.


 * Place blue portal on protruding wall facing double door.

Use the cube to bounce the pellet in the side room into its receiver.

Place the cube onto the button for the second door, and stand on the edge of the button for the first door, allowing the pellet to pass by without hitting you. It will be captured by the receiver, but the emitter will continue to produce more pellets.

In front of the protruding wall, place the cube on the floor such that it will ricochet the pellet off the ceiling and into the last receiver.

You can now use the already placed portals to get back up top and proceed to the exit.

---Alternate 2 Portal Solution--- Navigate with companion cube and enter room where the three Lifts are in the floor. Take cube to last lift and place in left corner if looking at exit direction. Jump on top of Cube and then proceed to Jump and Grab(E) alternatively till you get onto raised section(May take some practice) !*Possible if done right to get onto raised section with cube and complete level with 0 portals*!. Once on raised section proceed to area with button. Place portal on ground next to button and return for your cube. PLace opposite portal anywhere in Lift room and finish with 2 portals but not playing with pellets. Awards are given at 4, 3, and 2 portals.

Steps
Awards at 215...

Time
Awards at 2:20, 1:45...