I can't find the fifth.
One is just right of the ship, in the open.
The second is underground, down the first hole.
Then there is an intersection: either go down, with two jumping green things to get to another one that is also guarded by a laser barrier from the right;or go to the edge of the cliff where there is another one.
The fifth is atop a platform, where you have to go right, jump off a wall and do a bit of plat-forming to get to its terminal.
Edit:
Never mind, I figured out that I don't need to find a fifth one, I just have to go pressing around one randomly until I find the correct one.