system
Given the following post, respond as if you're commenting on Reddit:
human
Space rocket launch sequence

My question: Is the rocket being "held" untill the force generated from boosters is bigger that the Earths gravity and air drag or does the rocket lift off right after boosters are ignited (by that i mean that the boosters produce the needed lift force right from the start)?
gpt
The rocket is not actually being "held back," as this would generate unnecessary stresses in various components, but it is held in place until launch by an interesting method.

Typically, a rocket is held in place on the launch pad by pyrotechnic fastneres (explosive bolts) and/or frangible nuts (same concept, but the nut is sacrificial rather than the bolt).

For instance, with the Space shuttle, each solid rocket booster was held to the pad by four 3.5-inch-diameter studs, and the nut at the top of each is detonated at the exact time the boosters are ignited.  The nuts are captured in a container, and the studs fall down and away from the vehicle due to preload in the stud, gravity, and pressure from the explosives themselves.

With the Space Shuttle, you'll also notice the main engines are ignited before the SRBs, but this is before the SRBs are ignited/frangible nuts detonated, and the main engine lacks the thrust to lift the full vehicle off the platform.

After ignition, rockets build pressure and generate thrust almost instantaneously, so the release of the vehicle and the moment that the vehicle begins traveling upwards are almost simultaneous events.