Another view of the 'swimming pool'. Nylon-type bags are used to pool water for sound suppression and thermal conditioning. The two red squares at the base of the SRB Aft Skirt are the 'Dog House Covers'. These covers protect the Mobile Launcher Platform (MLP) Hold Down Posts. The north-side posts see the full brunt of the 5,000 deg F SRB plume as the vehicle 'walks' off the pad to the north. The south-side posts do not see full plume inpingement and, therefore, do not have Dog House Covers.