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the_fungible_man t1_j21wgcw wrote

>Why wasn’t the module adjusted on the launch pad so this wasn’t necessary?

Several reasons.

The launch pad/tower infrastructure (elevators, hold down clamps, umbilicals) are designed to mate with the launch vehicle in a specific orientation. But even if you could rotate the whole kit and caboodle, it wouldn't help:

For launches with non-instantaneous launch windows, such as the Apollo missions, the trajectory the vehicle will take once it clears the launch tower varies depending on when liftoff actually occurs. Therefore, there is no pad orientation which would eliminate the need for the roll maneuver in every case.

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gagaron_pew t1_j21yd69 wrote

it is possible to "rotate the whole kit". i think the russians are still doing it, or at least were doing it that way.

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Barrrrrrnd t1_j21zyau wrote

Possible but not worth the cost in retrofit when they can just roll the vehicle.

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the_fungible_man t1_j222q69 wrote

Interesting. It appears that rotation of Soyuz launch vehicles was necessary until the Soyuz 2.a which first launched in 2004.

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bigboilerdawg t1_j22m6nt wrote

So the roll angle varies depending on the time of the launch? I never knew that.

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the_fungible_man t1_j22o51w wrote

It's the flight azimuth that changes as the Earth rotates during the launch window. The rocket rolls to align itself to its flight azimuth so its flight path then becomes a simple pitch program.

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gagaron_pew t1_j21x87n wrote

its easier to roll the vehicle in the air than to build the whole launch infrastructure on a turntable.

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DudeWithAnAxeToGrind t1_j22dtuy wrote

Because rolling the vehicle in flight is trivially simple, while attempting to roll entire launch pad to be "properly" oriented at the moment when launch actually happens is very hard.

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SpartanJack17 t1_j22ktp8 wrote

Hello u/Oncey1234, your submission "Apollo role manoeuvre" has been removed from r/space because:

  • Such questions should be asked in the "All space questions" thread stickied at the top of the sub.

Please read the rules in the sidebar and check r/space for duplicate submissions before posting. If you have any questions about this removal please message the r/space moderators. Thank you.

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MrZorg58 t1_j21r51m wrote

Same as the Shuttles, they were all designed to do it.

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MrZorg58 t1_j224fka wrote

Guess this answer didn't solve your issue?

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misterjive t1_j21w1pn wrote

Because if you decided to tilt the Saturn V at an angle on the launchpad it'd fall over and that would be bad.

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