Why is the rocket launched vertically? In fact, there are also rockets launched sideways.

1June 16, the Long March II F- 13 carrier rocket carrying the Shenzhou XIII manned spacecraft was successfully launched at Jiuquan Satellite Launch Center. Whether it is a satellite or a space station, when they fly around the earth in space, the direction of motion is parallel to the surface. In other words, they all fly sideways along the ground in space. But when we watch the rocket launch, the rockets are all launched vertically, and then adjusted to fly sideways in space. Why can't the rocket be launched horizontally in the first place?

newton cannon

Launching rockets sideways is not without theoretical basis. Newton, a famous physicist, once imagined that if a cannon was set up on a mountain and then a cannonball was fired parallel to the surface of the earth, as long as the speed of the cannonball was high enough, the cannonball could always fly around the earth like a satellite and never fall. Newton also calculated the minimum speed of satellite flight, which is the so-called first cosmic speed. But in fact, the rocket can not be launched horizontally, which is mainly limited by two problems, one is air resistance, and the other is rocket structure.

air resistance

How big is the air resistance? Many people know that air resistance is directly proportional to the square of speed. When we are driving at the speed of 120 yards on the expressway, 80% of the oil in our car is used to overcome the air resistance. If the speed reaches 160 yards, the proportion can reach 95%.

The speed of a rocket is almost more than 200 times that of a car, so when the rocket flies in the atmosphere, the energy consumption of the rocket by air resistance is quite amazing. In order to reduce the energy consumption of rockets, we must reduce the flight time of rockets in the atmosphere. Obviously, a rocket flying vertically can fly out of the atmosphere faster.

Rocket structure

In addition to air resistance, the structure of rocket body is also a problem. We know that the longer something is, the easier it is to break. Rockets are very long and have great mass. If it is launched horizontally, gravity will act on the side of the rocket. Such a flight is extremely unstable, and the strength of the rocket may be unbearable.

A rocket launched sideways.

Smart readers may think: Since the air resistance in the atmosphere and the huge rocket volume prevent the rocket from launching horizontally, can it be launched horizontally if a small rocket is launched in a thin atmosphere?

The answer is yes. American Orbital Science Company invented a Pegasus rocket. It is very small, and can be sent to a place with thin atmosphere by plane, and then launched horizontally on the plane like a missile, and finally sent to space.

This kind of rocket has many advantages. The first is to launch in a thin atmosphere, so you don't have to worry about air resistance and consume less energy. Secondly, it can make use of the initial speed of the aircraft to make the launch more convenient; Third, it does not need a huge launch site, and can be transported and launched by plane at any time; Finally, this kind of rocket is safer because the plane can be transported and launched over the Pacific Ocean. Even if the launch fails, there is no need to worry that the rocket will hit people.

Of course, this kind of rocket also has shortcomings. First, launching a rocket on an airplane requires very high stability of the airplane and the rocket during the flight, which is very technically difficult. Second, this rocket is small in size and limited in carrying capacity, and can only launch small satellites.

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