Improved Space Shuttle

This is an improved version of my original Space Shuttle. I tweaked the SRBs, the external tank, and even fixed the orbiter a little bit. The orbiter is still technically the same as the original, except I fixed a modeling error that, in hindsight, isn't too much of an inconvenience. But whatever! ^^

Credits and "printing instructions" are on the original page, but just know that the orbiter without the attachment point is labeled here as "standalone," instead of the orbiter WITH the attachment point being labeled as "for stack."