SPACE SHUTTLE APPROACH
And we think we have it tough!

by Unknown

Yesterday morning, I rode my bike up to the top of a nearby hill (Mission Peak) to see if I could spot Columbia on its re-entry. I had seen the launch couple weeks earlier when I happened to be in the Orlando area. I got some info on its profile from the Kennedy Space Center web site. It came overhead at 8:47am PDT according to the published data (we couldnt see it because there were clouds in the way, and the plasma trail on reentry cant be seen in daylight, they say, even though the leading edges of the Orbiter are glowing at 1750 deg C). They predicted the over-pressure shock wave front would hit the surface 7 minutes after overhead passage, and we heard the sonic boom right on time. Of course, by that time, Columbia was probably 1000+ miles E. of us, as it was at an altitude of 45 miles, traveling at 15000mph as it crossed over us. The descent rate was 17000 fpm (that's what my Pitts will do going straight down) and these guys were in a, get this, glide, pitched up 28 deg! They were also only 22 mins away from touchdown at KSC's landing site, 22 mins to lose 225000 feet and slow down from about Mach 20 to 250 knots. They're supersonic until less than a minute before touchdown, and the gear speed is less than 300 knots, so they can put it down only seconds before touchdown, on short final. I was interested to learn that, just like any good glider pilot, they S-turn on approach in order to lose altitude and enter the heading alignment terminal phase on speed and altitude. The only difference is that these S-turns are all supersonic and performed up there above the tropopause, and on instruments. Sierra Hotel.