How fast the missile needs to fly away from Earth?

The missile must fly very quickly to escape the earth because the Earth has gravity – the force that people experience everyday. Attractive forces dragged people towards the ground, keeping people standing on earth instead of drifting out of the space.

However, gravity also makes it difficult to leave the earth with space missiles. Gravity is not only strong but it has a large range, extending around the planet.

Basically, the missile must make the thrust by burning the push to produce hot air, then spray hot air out of the nozzle. This process is similar to an exaggeration of a ball and then releases his hand, causing the ball to fly away when the gas escapes.

The push of the missile includes both fuel and oxidants. Fuel is usually flammable like hydrogen, methane or kerosene oil. Oxidation is usually liquid oxygen, reacts with fuel and causes fire.

To get rid of the earth and launch into the space, the missile needs a lot of force, so they consume the pushing quality very quickly. It was a problem because the rocket could not bring enough push to create a thrust forever. The large amount of thrust will make the missile too heavy to take off. When the substance is pushed out, the pushing force disappears and the gravity slows down the missile until it gradually falls back to the Earth.

Fortunately, scientists can launch missiles with a bit of horizontal momentum so that when they return, it does not crash into the earth. They can even cause the missile to “constantly fall around the Earth”, which means entering the orbit and begins to turn around the planet.

Many means of deliberately not leaving the Earth completely. There are thousands of satellites rotating around the green planet, helping phones and TVs to work, displaying weather models for meteorologists, even allowing buyers to use credit cards to pay at the store. or gas station. Sometimes people can see these satellites, even the International Space Station (ISS), in the night sky.

But sometimes, the goal is to completely escape the gravity of the Earth and fly into a distant space. At that time, scientists use the method of separating the missile floor. Initially, a large missile launched, but when it reached the space of the missile floors was gradually removed. In this way, the journey can continue without the large weight of the initial missile, the pushing quality is also reduced.

Even with this method, the missile will finally run out of push. But if the rocket flew quickly, it could run out of the push but still drift away from the Earth, not pulled back by gravity. This is like cycling, if creating enough speed, the car can run without the driver without pedaling.

Like bicycles, missiles also have a minimum speed threshold to move by themselves. The minimum speed threshold that the missile needs to drift into the space is 40,000 km/h. Scientists call this the escape velocity. The missile needs to fly so fast so that the momentum pushes it out of Earth stronger than the gravity. If slower, the missile will enter the Earth’s orbit.

Larger mass objects will have stronger gravity. Therefore, missiles launched from a larger planet than the Earth will need a higher escape velocity. For example, Jupiter is the planet with the largest mass of the solar system, so large that it is possible to swallow 1,000 Earth. Therefore, this planet requires very high escape velocity: 214,000 km/h, more than 5 times more than the Earth’s escape speed.

But Jupiter is still very small compared to black holes – an extremely large mass object. The escape speed of the black hole is so high that even the light at a speed of more than 1 billion km/h is not fast enough to escape.