Bright Sword starts with the grenade flat.

Chapter 338 Gravitational Slingshot
After hearing Liu Qi's words, Liu Xiu sighed and said:

"It's too late. Have you read the latest report on the timing of the solar helium flash from the observatory?"

Liu Qi fell silent after hearing Liu Xiu's words, because he had also read the latest observation report on the helium flash. Based on his continued attention to the sun, the sun's helium flash will occur in about eight years, that is, in 2078.

If we don't use Jupiter's gravity to form a gravitational slingshot for acceleration, it would be difficult to push the blue planet to a safe enough distance relying on the thrust of the planetary engine itself.

The term gravitational slingshot does not only appear in Wandering Blue Planet!

In fact, in the movie "The Martian", in order to reach Mars, the Hermes spacecraft needs to enter the gravitational range of the blue planet at a precise angle. The spacecraft uses gravity to gain acceleration, and after circling half a circle, it swings towards Mars to carry out rescue.

Of course, the most powerful gravitational slingshot must belong to "Interstellar", which directly uses the gravity of the black hole to let the black hole pull them to the calculated critical point. The spacecraft instantly ignites and uses the gravitational slingshot effect to shoot the spacecraft to a new planet.

Although this may seem counter-intuitive, it is actually completely consistent with the laws of physics.

In deep space exploration, according to the law of universal gravitation, spacecraft are constantly affected by the gravitational forces of various celestial bodies. Assuming that the range of influence of the gravitational force of each celestial body is a sphere with itself as the center and different radii, it is called an influence sphere.

A spacecraft moves in the gravitational field of the sun most of the time, but when approaching a planet, the planet's gravitational force on the spacecraft is much greater than the sun's gravitational force, so the influence of the sun's gravity can be temporarily ignored.

Therefore, we can assume that the spacecraft enters the influence sphere of a planet at time 1 and flies out of the influence sphere of the planet at time 2. From the perspective of the planet, after the spacecraft enters the influence sphere, ignoring the gravity of the sun, the flight trajectory is a conic curve. According to the symmetry of the trajectory, the speed of entry is equal to the speed of flight. If the speed of the spacecraft is equal, then why can it achieve gravitational acceleration?

In fact, the key to the acceleration of a planet's gravitational slingshot is that the planet itself has a speed.

You should know that the word speed is not a single word, but a comparison between two objects. This was mentioned in junior high school physics!

When a person runs on the ground, the comparison is with the surface of the Blue Planet. However, if the sun is used as a reference, even if a person sits on the Blue Planet and does not move, the speed is 30 kilometers per second, which is far higher than the speed of most satellites and rockets!
Therefore, when the planet is used as the reference system, the speed of the planet itself is ignored, and the speed of the spacecraft entering and flying out is the same relative to the speed of the planet.

However, if we look at it from the perspective of the solar system, the angles of entry and exit change, so the resultant speed also changes, ultimately achieving an increase in absolute speed. This is the so-called gravitational slingshot.

Therefore, in deep space exploration, since the fuel carried by the spacecraft is limited, it is generally necessary to fly near a planet and use the gravity of the planet for acceleration, and sometimes even use the gravity of multiple planets for acceleration. This is why in deep space exploration, the orbits of spacecraft are often very complex.

Take the famous Voyager 1 for example. Before it passed through Jupiter's gravitational slingshot, its speed was only 14 kilometers per second. Obviously, it has no way of leaving the solar system at such a speed. The most likely possibility is that at some point its speed is exhausted and it will be pulled back by the sun's gravity, and then either directly crash into the sun and burn up, or become an existence like Halley's Comet.

However, after being accelerated by Jupiter's gravitational slingshot, its speed has reached 37 kilometers per second. This speed is naturally far greater than the escape velocity of the solar system. This is why Voyager 1 can fly away from the solar system.

So theoretically speaking, without a method like a gravity slingshot, it would be basically impossible to escape the solar system by relying on the speed and thrust generated by ordinary chemical rockets.

Although the Wandering Blue Star uses the thrust generated by the heavy fusion engine, its thrust-to-weight ratio is much greater than that of ordinary chemical rockets, but don't forget that although the thrust generated by each engine has reached 150 billion tons, 10,000 thrust engines have a thrust of 150 trillion tons. However, although such a thrust looks huge, it does not seem too much when placed on a mass of 600 trillion tons.

If calculated using thrust-to-weight ratio, then its thrust-to-weight ratio is only 0.0000000025.

The smaller the thrust-to-weight ratio, the weaker its acceleration. This is similar to the acceleration of a car from 0 to 100 km/h. The weaker the engine horsepower, the slower its acceleration.

So if we don't use Jupiter's gravitational slingshot, then theoretically it is impossible for the Blue Planet to have the speed to escape the solar system.

Of course, we also have to thank Jupiter, because the gravitational slingshot is relative to the large mass object on the small mass object. If the mass of Jupiter is very small or even only as large as Mars, its blue planet will not be able to produce gravitational slingshot at all. The final result may even be a collision between the two planets, or Mars will be attracted by the gravity of the blue planet and change its original orbit.

Therefore, as long as Blue Star can achieve an acceleration of more than 20 kilometers per second, or even more than 10 kilometers per second like Voyager 1, then Blue Star will be able to gain the speed to escape the gravity of the sun.

However, it is not easy to obtain a gravitational slingshot, because when being captured by Jupiter's gravity, one thing must be done, that is, to have extra thrust at the critical moment to push it out of Jupiter's gravitational circle.

Without this extra thrust, it would have been captured by Jupiter's gravity like many other comets and eventually become a part of Jupiter.

But now the most critical issue is the thrust. You must know that the Blue Planet is not Voyager 1, which is very light, so using a rocket engine can easily change its posture and allow it to escape from Jupiter's gravitational circle.

However, due to the mass of the blue planet itself, its flight posture is difficult to change, or it takes a long time to change it bit by bit.

Fortunately, Jupiter has a large amount of hydrogen, while the Blue Star has a large amount of oxygen, so the orbit of the Blue Star can be adjusted by the explosion shock wave of the hydrogen and oxygen mixture.

And the thrust required does not need to be very large, just a little bit will do.

Of course, the actual situation is not just the Jupiter crisis, the most important one is the intelligence crisis. With the application of intelligent programs, artificial intelligence has actually given birth to self-awareness.

Because both now and in the movies, they have shown an autonomous sense of crisis, and they regard humans as a threat to themselves.

For example, in the movie, the plan to ignite Jupiter was not proposed by Liu Qi at first, but had been proposed by someone earlier. However, Moss's virtual calculations showed that the success rate of this plan was almost zero.

So the Blue Planet was abandoned, but then Moss could put all humans into hibernation until they died and it could take the pilot space station to the next planet to replicate itself.

You know, the Navigator Space Station is not only used for navigation, but also for mankind's Spark Plan. It has everything!

(End of this chapter)