Answers Your Questions
From: Andy Hardy, of Nottingham |
To: Bill Reeves, flight director for the planning team
Question: Why does the shuttle have to role after launch and not start in that position in the first place?
The shuttle rolls to an inverted position just after launch so that it can point antennas on the top surface of the vehicle at ground tracking stations. While there are antennas on the lower side of the vehicle, they are blocked by the external tank and the solid rocket boosters.
As for the second part of your question, why not start out in this position in the first place? The answer stems from the fact that we are reusing facilities built for the Apollo Program. We mate the shuttle with its tank and boosters in the Vehicle Assembly Building, and then it is transported to the launch pads along the crawlerway by the crawler/transporters, some of the largest tracked vehicles ever made. The crawlerways are specially constructed to handle the immense weight of the crawler, mobile launch pad, and the shuttle stack; but they have no place to turn around. So, whatever leaves the VAB for the pads ends up facing the same direction as when it left. The costs to add such a feature to the crawlerway are so high that it was much cheaper to turn the shuttle in the air than it was to turn it on the ground.
More information on the facilities at KSC can be found at:
Hope this helps,