Entry Profile for IFT4
Entry Profile for IFT4
Reddit User maxfagin created this charts from the telemetry data of the live stream
Interesting that there's nothing special about acceleration at max-Q, unlike during launch.
What is Max-Q?
It stands for "maximum dynamic pressure", and is a fluid dynamics concept. It's the moment when the spacecraft is under the most stress, and therfore where certain things are most likely to fall apart.
It's caused by a combination of atmospheric density and velocity. To avoid issues, there's a rough rule of "don't accelerate too much until you're high enough that the atmosphere thins out" during launch, and "don't hit the atmosphere too fast" during reentry.
Here's a chart for the IFT-3 launch. At one minute you can see that acceleration decreased for a few seconds, to minimize the strength of max-Q.