I got the same problem, solution is this:
Jan says she will land in the canyon, but guess what - there is a second one!
Go the hall where the ATSTs stand (those one that wont move, near the room where you dropped the Ioncannons shield)
Right on the opposite side of the door from which you enter is another which (is) was locked. Your gotta try running around in the room and re-enter it several times maybe until 3 Stormtroopers come out of the door. Voila, the way is free after you killed these.
Just dont give up if it wont open. Try to leave the whole spot once and go there again. If still nothing will happen, you might wanna play the game again or use the "no clip" cheat to pass the door. (SHIFT+the key left of your "1" to get the console. Enter helpusobi 1 to enable the cheatcodes, then enter "noclip" to make you able to fly thru the door. If you passed it, reenter noclip to put it off again. )
Hope it helps ...