*sigh*
From the package description at Orbit Hangar:
"This package should only be installed over an installation of Orbiter that includes the full shuttle fleet, the ISS fleet and the STS expansion pack V4.1.5."
So, you need to download the following packages and install them in the order listed here:
1.) Shuttle Fleet V4.1.5:
[ame="http://www.orbithangar.com/searchid.php?ID=3730"]Shuttle Fleet V4.1.5 FULL Package[/ame]
1a.) Shuttle Fleet Service Pack #1 (optional but recommended):
[ame="http://www.orbithangar.com/searchid.php?ID=3744"]Shuttle Fleet V4.1.9 (SP2)[/ame]
2.) ISS Fleet V2.1.0:
[ame="http://www.orbithangar.com/searchid.php?ID=3676"]ISS Fleet V2.1.0[/ame]
3.) STS Expansion Pack V4.1.5:
[ame="http://www.orbithangar.com/searchid.php?ID=3777"]STS Expansion Pack V4.1.8[/ame]
Then download and install the STS-119 expansion package last:
[ame="http://www.orbithangar.com/searchid.php?ID=3846"]STS Expansion Pack V4.1.8 (Special Edition)[/ame]
Please pay attention to the manual for the ISS fleet and the STS Expansion Pack as there are several 3rd party add-ons needed for a proper installation.
If you are new to Orbiter you may want to wait until you are more familar with the base packages and how Orbiter works before taking on the Shuttle Fleet. It isn't easy, after all this is rocket science!
Good Luck,
Dave