We know of the ISV and Valkyrie shuttle. Though how else has it improved?

Here is my sketch comparing today's space shuttle to the futuristic shuttle in Avatar. http://fc09.deviantart.net/fs71/i/20...ju-d3hf0rw.jpg

The Valkyrie shuttle is about the same size as the International Space Station from nose to tail.

Valkyrie shuttle length 101 meters ( just over 300 feet).

ISS truss length 110 meters ( 358 feet) International Space Station - Wikipedia, the free encyclopedia