IF YOU NEED TO REBIND A KEY THERE A I TOOL FOR THAT HERE! Link
As Stated befor. IT IS HARD TO FIND KEYS NOT ALREADY TAKEN BY THE GAME! GAME DOES NOT LET U REBIND KEYS TO ANYTHING.
I have not done it but i nocied something when i had the choice of thes missions.
On that mission where u get to choose if u want specters or ghost. Right be4 u choose save the game looking at the screen. Star mission then load your save start other mission. it then gave me both missions in the prior mission terminal. Maby this will allow you to get both.