I want to get an idea of how long the falcon 9 rocket accelerates and at what g level. Ideally a plot of gs vs time. I see various statistics like specific impulse and thrust and weight, is there a way to calculate average accel from the basic rocket data? I suppose average thrust and weight gives you average accel...


From the telemetry link mentioned by @jkavalik, someone posted an interesting graphenter image description here:

The blue line here is the acceleration of the rocket. It ramps up as fuel is consumed. There's a dip from about 55 to 85 seconds where I believe the engines are throttled back in anticipation of "max Q", the point of highest aerodynamic stress. The acceleration then increases continuously until the first stage shuts down and separates. There's a few seconds of free fall before the second stage ignites, and it likewise ramps its acceleration up over time.

I'm not sure what the units are supposed to be; the data the creator was working from was given in kph rather than m/s. The Falcon 9 Manual says that full-weight payloads will take a maximum of 6g axial acceleration. so the peak of the blue line should be something under that, probably in the ballpark of 5g.

  • $\begingroup$ Note that 100 kph per second is 27.8 m/s^2, or 2.83 gees, and this Quora answer suggests it peaks at about 35 m/s^2 (3.6 gees). So I think the y-axis has to be in km per hour per second. Note that the force experienced by the payload also includes 1 gee for the Earth's gravity at zero acceleration, so the force would peak at 4.6 gees. $\endgroup$ – Jess Riedel May 11 '18 at 20:35

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