Shuttle launch roll?

[Salun]

I have noticed that in the early shuttle Missions like STS-1 that during the entire of the launch the shuttle remain in a inverted position while most shuttle nowadays(If not all) Roll upright T+6 minutes. Just curious as to why is that? Near as I could think is the up right burns more fuel and or gives more clearance for the tank when its dropped.

 

[zerofay32]

I think it provides better communication between the shuttle S-band and the TDRS network.

 

[Urwumpe]

I have noticed that in the early shuttle Missions like STS-1 that during the entire of the launch the shuttle remain in a inverted position while most shuttle nowadays(If not all) Roll upright T+6 minutes. Just curious as to why is that? Near as I could think is the up right burns more fuel and or gives more clearance for the tank when its dropped.

Actually, it is just that now TDRS is available and the Shuttle can now switch sooner to this satellite system, permitting NASA to close one of their ground radio stations to save some money. The tank is otherwise blocking the communication line of sight to the satellite.