A space shuttle on top of an airplane
the planes are two in nuber
Space shuttle riding piggyback
The small plane is on the large plane. 
The sky is blue. 
NASA jet carrying space shuttle
NASA aircraft traveling in tandem
NASA jet transporting space shuttle
NASA jet with a space shuttle payload
NASA jet airplane carrying the space shuttle
Space shuttle being transported by a NASA jet
Space shuttle riding on the back of a NASA jet
Space shuttle piggybacking on a NASA jet
Space shuttle hitching a ride on a NASA jet
a large plane flying in the sky with it's carrying another plane behind it