A Virgin America A320 (L) flies in tandem with Virgin Galactic's White Knight 2 carrying Spaceship 2 over San Francisco, California in this publicity photo April 6, 2011. The aircraft were the first aircraft to arrive at San Francisco International Airport's new $388 million 640,000 square foot Terminal 2, which is slated to be the first LEED-GOLD certified airport terminal in the nation. [Photo/Agencies]

A Virgin America A320 (L) flies in tandem with Virgin Galactic's White Knight 2 carrying Spaceship 2 over San Francisco, California in this publicity photo April 6, 2011. The aircraft were the first aircraft to arrive at San Francisco International Airport's new $388 million 640,000 square foot Terminal 2, which is slated to be the first LEED-GOLD certified terminal in the nation. [Photo/Agencies]