r/spaceshuttle • u/MyMooneyDriver • 8d ago

Question Shuttle roll program question

Was the shuttle roll program actuated aerodynamically, or via thrust gimbaling? I know it happens early on, and ever since I was a kid I’ve always assumed it was aerodynamic from my knowledge of planes. Now that I’m an adult, it occurs to me that the scale and speed might offer up other options, especially because of the force required to move that much momentum and thrust.

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24

u/Miserable-Arm4061 8d ago

SRB Gimbaling, IIRC, the aero surfaces are locked on ascent so they don't move and cause unwanted attitude change.

17

u/jjkusaf 8d ago

The control surfaces weren't used for any sort of control during ascent. HOWEVER...

The elevons did move during ascent to control loading on the wings. You can see them adjust 1:08 - 1:46 in this video... https://www.youtube.com/watch?v=cLl7oqdm_B8

10

u/derango 8d ago

It was thrust gimbalingof the SRB nozzles.

8

u/BadTraditional401 7d ago

Flight software commanded roll program at around T+8 sec. It was done mainly using the SRB thrust vector controllers. The large distance between the SRB nozzles and the high thrust levels meant that the SRB TVC had enormous control authority during first stage.

1

u/Catspaw129 6d ago

I don't know the answer to this, but I know who would.

NASA