The time from first call to landing is only 10 minutes and the speed with be between M2.0 and M1.0 until it hits the timing circle. All they could aim for would be to get all airborne aircraft out of a circle radius 30nm based on Fairford to avoid the brick coming down......
NOTAM from 1992:.......
b. Any arrival of the shuttle aircraft at RAF Fairford will be an emergency situation.
c. The aircaft will contact RAF Fairford on frequency 243.0 Mhz 10 minutes prior to landing. It will remain on this frequency until landing.
d. The shuttle aircraft is NOT transponder equipped.
e. The shuttle aircraft CANNOT accept vectors for any reason.
f. Traffic information is not wanted by the shuttle crew.
g. The sponsor will maintain an open line of communication with RAF Fairford from launch until launch +10 minutes when vulnerability has passed for the launch phase.......
The diagram shows the classic shuttle descent into the timing circle with the shuttle passing FL600 about 35nm out and FL300 about 10nm out.
IIRC it was only ever an option for a launch into a polar orbit, which is not planned for any of the remaining shuttle missions.