The propellant is primarily needed to get the spacecraft into orbit, not to stay in orbit. ... When about half the propellant is burned, the bottom half of the rocket is jettisoned.

How much fuel does a spacecraft need?

At liftoff, the two Solid Rocket Boosters consume 11,000 pounds of fuel per second. That's two million times the rate at which fuel is burned by the average family car.

What happens if a spaceship runs out of fuel?

In rocket flight, forces become balanced and unbalanced all the time. ... As the engines are ignited, the thrust from the rocket unbalances the forces, and the rocket travels upward. Later, when the rocket runs out of fuel, it slows down, stops at the highest point of its flight, then falls back to Earth.