The scientific principle that allows a space shuttle to achieve lift off is Newton's Third Law of Motion, which states that for every action, there is an equal and opposite reaction.

Here's how it works:

* Action: The space shuttle's engines burn fuel, expelling hot gases downward.

* Reaction: The expelled gases push back on the shuttle, propelling it upward.

This principle is also known as the principle of jet propulsion. The enormous force of the hot gas pushing down creates an equally large force pushing the shuttle up, overcoming the force of gravity and allowing it to lift off.

Other important factors that contribute to lift off:

* Aerodynamic lift: The shape of the space shuttle's wings and body creates aerodynamic lift, helping it to gain altitude as it accelerates.

* Thrust-to-weight ratio: The shuttle's engines must produce enough thrust (force) to overcome its weight and accelerate it upward.

* Fuel and oxidizer: The space shuttle uses a combination of liquid hydrogen and oxygen as fuel, which when combined create a powerful combustion reaction that generates the thrust needed for liftoff.

The combination of these factors working together allows the space shuttle to achieve liftoff and escape Earth's gravity.