@daniel yes, but it was decided to use the 747s as they were found to be less aloof and more reliable for transporting, especially over long distances.. as the giant cats tended to get distracted with warm napping spots, catnip, food and occasional city wide pets and it was delaying arrivals and subsequent launches. it was also found during initial testing that sometimes when catnip would become involved, the giant cat would roll over and crush said shuttle, but that wasnt disclosed to the public, they would just rename subsequent shuttles with the same name to pretend there was an unbroken line of flights... its also possible that giant cat hairball might have played a part in several shuttle accidents over the years... some on television, some found before they reached that level of destruction.