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I am trying to model the launch of the space shuttle (up to 120km of altitude) from Cape Canaveral, Florida. In order to do so I would need to know when the gravity turn part of the flight starts and stops.

I know that the gravity turn starts 20 seconds after lift off with a pitch angle of 78 degrees. (source look at left column)

Before that I will assume vertical flight.

I could find a paper in which figure 5 suggests that the gravity turn for ARES 1 starts 20 seconds after lift off and ends 130 seconds after lift off. But I don't know if the same would be true for the space shuttle.

I could not find any data about when the gravity turn stops for the space shuttle neither could I find at what angle of attack (& pitch) the space shuttle continues. Does anybody have this data?

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    $\begingroup$ This is too partial for even a partial answer, but in Space Shuttle Technical Conference Volume I, page 187 (202 of the pdf) there's a plot of angle of attack, but only for the first two minutes. ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19850008580.pdf $\endgroup$ Aug 17, 2019 at 13:31
  • $\begingroup$ Seeing the small angles of attack I would say that the gravity turn already lasts for at least 2 minutes, or does it continue with such a small angle of attack after the gravity turn? $\endgroup$
    – ThaNoob
    Aug 17, 2019 at 13:49
  • $\begingroup$ You might be interested to read this answer and especially its linked references: space.stackexchange.com/questions/23137/… $\endgroup$ Aug 17, 2019 at 13:55
  • $\begingroup$ I have read it, but I don't really see how it explains the question. It shows the gimbal angles of the engines but I would need to know the angle of attack that results from the trust that no longer goes through the CoM. What is the important part in your post? $\endgroup$
    – ThaNoob
    Aug 17, 2019 at 14:13
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    $\begingroup$ You mean the DOLILU software system? It is interesting, but above my capabilities, I would like to start with something that I can solve analytically (taking some rough assumptions and now I am trying to figure out which these assumptions are) $\endgroup$
    – ThaNoob
    Aug 17, 2019 at 14:56

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The gravity turn was effectively over about 350 seconds after liftoff.

This can be seen in the graph of flight path angle vs. time.

enter image description here

(This is from a study of heads-up vs heads-down ascents, but the answer is the same for both).

Source: A Study to Evaluate STS Heads-up Ascent Trajectory Performance

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  • $\begingroup$ A gravity turn is defined by two things: 1) Thrust is not used to change the spacecraft's direction, and 2) During the initial ascent phase the vehicle can maintain a low or even zero angle of attack. The relative "flight path angle" is the difference between the vehicle's velocity vector (not its orientation) and the horizontal vector. This chart is not an answer to the question without a good explanation (and reference) that explains how one can obtain the angle of attack and the amount of thrust used to change direction from the flight path angle. $\endgroup$
    – phil1008
    Jan 4 at 6:50

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