The computer warns you that this next test is impossible and commands you to make no attempt to solve it. Whatever. She's lying.
The particle field is between you and the red button, so you can't take the cube through it. You also can't shoot through it to make a portal in the blue room. However, you can walk through the particle field and shoot a blue portal onto the wall that way. But that still doesn't let you get the cube through the orange portal, because it's on a platform.
The solution is to create a portal in this first part of the chamber that you can put the cube through, making it end up on the platform near the orange portal. Then, walk through the particle field, create a blue portal, and pick up the cube from the platform. See? Totally not impossible.
Go into the elevator to the next chamber.