Max Q

Rocketry gets a lot easier once you make it into space. In the vacuum, there is nothing to displace, but sitting on the launch pad the rocket sees nearly $100 \, \textrm{km}$ of atmosphere to get through.

After the Falcon takes off, it compresses and pressurizes the air above it, creating an even thicker layer to push through. As the Falcon accelerates, this compression continues, putting even more stress on the rocket and engines until it reaches a maximum: a point called max-q.