stuck on top of the citadel

[kolossus]

I am on top of the citadel just before Dr Breen teleports. The gunships harrass me, but that is not the problem. What do I have to do to progress? Have tried to get the 'flaps' of the tower up by shooting the energy balls at them, but it doesn't work.

[giant384]

scoot over to the right more and shoot at the big light thingy then it will end

[emCee-ig]

you have to move to your left and use the energy balls to shoot off the sides of the teleport, but when it starts to explode,,, move, or you will fall to your death

[kolossus]

Thanks guys, I finished this section (never knowing that it was the last).
As a matter of interest: I did it from the right.