Musk tells jokes about rockets.

At 5: 45 am on February 10, Beijing time, Musk's space exploration technology company launched another large starship prototype spacecraft in southern Texas.

The circular spacecraft launched this time is numbered SN8, which is the eighth spacecraft in this series. The whole flight lasted about six and a half minutes, and finally exploded when landing, turning into a wreck.

Although SN8 exploded, Musk was still very happy and sent a tweet saying "Mars, here we come!"

Some bad friends may have to talk about it. Why is your rocket happy when it explodes this musk? Now rocket technology seems so developed, why did it fail?

In fact, the ultimate goal of SN series prototype is to build a manned starship, which is very different from ordinary launch vehicles.

Because it must be able to carry 100 people at the same time and successfully land on Mars.

At present, the only planet that humans have landed on is the moon, which is only over 380,000 kilometers away from the moon, and Mars is 55 million kilometers away from the earth.

Moreover, due to the different atmospheric environment, gravity and other conditions, different planets are naturally different in spacecraft design, including how to fly long distances and how to land.

For example, about half of the probes launched by humans to Mars will be damaged during the landing phase. For manned spacecraft with more complicated design, the difficulty of landing is even more imaginable.

Although the fuel supply was insufficient during the landing phase of this test flight, which led to the engine flameout, deceleration during landing, and the explosion ended, the team had obtained all the required data in the previous flight.

He even used cheers such as "hell yeah", which is almost equivalent to the Russian shouting "Ula" after drinking vodka, which shows that he is very excited.

In his eyes, the test flight was absolutely successful and worthwhile.

What's special about this test flight compared with before?

First of all, the preset flying altitude of SN8 is 12.5km, which is much higher than the previous SN5 jump 150m, and SN8 has successfully reached this altitude.

Secondly, this is the first time that the Raptor engine, the most powerful commercial rocket engine on the ground, has carried out three flight tests at the same time, and it works normally all the time.

As the core power of the real starship in the future, the successful parallel test flight of several Raptor engines is of great significance to the starship.

Finally, this time SN8 completed a "juggling" during the flight: it changed from a vertical ascending state to a horizontal gliding state in a few seconds.

And after gliding to the designated place, it quickly becomes vertical and lands.

SN8 only relies on its three engines and four pneumatic control wings to accomplish these flexible movements.

These actions are called "belly flop" by space exploration technology company, which may seem normal in many people's eyes and seem to be seen in many movies.

However, we should know one thing: Before SN8 was successful, all similar scenes were realized by CG animation, which means it only existed in theory.

However, SN8 proves that it is enough to switch between the horizontal gliding attitude and the vertical landing attitude and complete the landing with the current design of the starship.

The reason why it became the most important harvest of this test flight is because this landing method is necessary for the starship to land on Mars.

Although there is an atmosphere on the surface of Mars, its atmospheric density is only about 1% of that of the earth.

The existence of an atmosphere with sufficient density means that aerodynamic drag will be generated, but due to the low density, it is not enough to generate enough drag to support Starship to slow down with a parachute in order to land at a safe speed.

Therefore, if a starship wants to land on Mars successfully, it must have the ability of pneumatic gliding, and at the same time, it must have a deceleration mode other than parachute.

Therefore, although the launch of SN8 failed to land and explode in the final stage, it has basically completed all the original test targets, which is an important milestone in the development of starship.

Looking at the SN series prototype spacecraft of Space Exploration Technology Company, so far only SN 1 and SN5 are considered "alive", and the rest of the launches have exploded. Later brothers and sisters didn't know how many boats were left.

However, the cost of SN series is well controlled. To put it bluntly, the workmanship is very rough, each of which is about one million dollars.

Look at this stainless steel shell, rough welding marks, and the manufacturing process of green leather train is much better than this. It can be said that the only valuable thing in SN series is the engine.

Therefore, as one of the richest people in the world, Musk can fully afford it.

These explosions are not completely meaningless. Every explosion can help to eliminate some possible dangers on the future star ship, and finally it will be foolproof when it is actually manned.

What's more, under the smoke of repeated explosions, what is hidden is the great progress of space exploration technology companies, which has made countless people see that the dream of immigrating to Mars is no longer so far away.

Perhaps, as Musk said, we are really not far from Mars.