Columbia was different to all the other orbiters because it had a SILTS (Shuttle Infrared Leeside Temperature Sensing) pod added to the top of the tail. This was used a number of times to measure the temperatures being experienced by the orbiter during re-entry.
I’ve been told that other shuttles also had the SILTS pod, and seen some model builds of other shuttles that feature it but to the best of the research I’ve done Columbia was the only one to have this. For example, the picture below is of the fin of Atlantis, where as far as I can find out no camera was ever fitted. These pictures also show one of the problems with doing an accurate representation of a shuttle. The pattern of tiles varies between them all, just look at the black tiles around the top of the fin on Columbia for example. Many more examples will no doubt follow.
The picture on the right shows the SILTS camera fitted to Columbia. This was taken as the orbiter was moved to the vehicle assembly building (VAB) in preparation for mission STS-107.
Fitting of the SLITS pod is a simple affair. The kit parts were marked up using the resin parts as a template. The tip of the fin was then cut off.
And the resin part was glued on following a little bit of sanding and fitting.
Although there is still some sanding and shaping required the SILTS pod now sits on the top of the tailfin.
There is also a need to add a parachute to the bottom of the tail area, which were fitted during the lifetime of the shuttles. You can see this area quite clearly in this picture taken during the rollover of Columbia to the vehicle assembly building for flight STS-107. It is the area at the bottom which has black tiles on the lower surface. This will be done by cutting a section out of the kit parts and rebuilding it with plastic sheet.
I found (sorry I can’t remember where now as too much time has elapsed) this very useful diagram of the parachute area and what is needed to make it more accurate.
So started by marking up the line where the piece would be cut out.
And with that part removed.
And then built up the underside part according to the diagram above.
Finally a fine cut was made into the control surface where it meets the tail at the top and bottom to give a small gap and show that this is a separate part.
That brings the tail to the right shape.
Unfortunately this part suffered when we moved house and got broken off. Should be a relatively easy fix with luck as doesn’t look like anything has been distorted out of shape.