How Stop White House being Destroyed?

[awesome1]

Can anyone give me a tip on how to stop the White House from being destroyed? Its in a bad mess when I take it and I am ordered to build Adat turrets north of White House so I surround the entire North area with them but all I get is White has been destroyed.........end of mission? There is also a 2 minute timer so have you got to get BOTH the Falling Star uplinks down within that time? Can you find and take the falling star uplinks before taking the White House? Can the White be repaired by anything?

Any help please :mad: