the piggy back ride is not used anymore.  when the space shuttle program was started, there wasn't a landing strip long enough at cape canaveral to land the shuttle, so they went to cali.  that and the fact that weather in cali was more predictable had them use that strip.  about 7 years ago, they expanded the strip at canaveral and started using it occassionally to see how it works.  they found it was much more cost effective to take off and land in one place (imagine that!) and so they have been doing it pretty much since then