Will the deorbit be auto-calculated or preloaded or can it be calculated "on the fly" and performed with manual DV inputs?
I understood the real shuttle accepted both ways.
Usually, the deorbit is planned on the ground and the burn data and procedures uplinked to the orbiter.
But you can also do a manual deorbit burn using PEG4, should communication with the ground be impossible.
Here you have an executive package for the crew of a Shuttle mission, send to them for flight day 10:
http://www.nasa.gov/pdf/523818main_fd10_ep.pdf
On page 20, you have the status of the landing sites and the next opportunities for the primary landing sites (Edwards and White Sands Northrop Strip)
The two PLS lines contain the information you need for landing the shuttle there, should the communication with mission control fail.
For example:
EDW22 ORB157 – 9/21:28 SCT150 BKN250 7 240/18P27
As much as I understand, this data is punched into one of the laptops ("Deorbit Manager", PGSC) and this calculates the actual deorbit burn data from this.
TEST:
http://www.cantrip.org/leap/pocsmp.pdf.gz