PAO: 3… 2... 1… mark, we are at T-4 minutes and counting… flight crew has been ordered to close their visors, the count has resumed. We are counting at 3 minutes 48 seconds and counting… total time in that hold was about 2 minutes 30 seconds, we will launch 2 minutes 30 seconds approximately after straight up noon. T-3 minutes 30 seconds and counting… T-3 minutes 15 seconds and counting… next major event in the countdown will be at 2 minutes 30 seconds, when the pilot Fred Gregory will clear the caution and memory system, T-3 minutes and counting… we are go for liquid oxygen pressurization of the external tank, T-2 minutes 45 seconds… T-2 minutes 30 seconds and counting, pilot Gregory now being told to clear the caution and memory system, and he is clearing as we speak – and no unexpected errors reported. T-2 minutes 15 seconds and counting… Liquid oxygen tank should now be approaching flight pressure… T-2 minutes and counting… the beanie cap has been removed from the external tank top and is now being cleared back on its umbilical arm. That arm will be clear in time for launch. T-1 hour… one minute 45 seconds and counting… The liquid oxygen tank is pressurized, liquid hydrogen tank now pressurizing… T-90 seconds mark… liquid hydrogen tank has pressurized and the range is ready… T-1 minute 10 seconds and counting… next major milestone occurs at T-31 seconds with the go for auto sequence start… mark, T-1 minute, 60 seconds and counting to the launch of Challenger and Spacelab 3… T-45 seconds mark, standing by now for the T-31 seconds auto sequence start… T-35 seconds… T-30 seconds and counting, we are now on auto sequence start, Challenger’s four computers now controlling the critical vehicle functions from now through lift-off.