At the same time as Mars and Venus were exploring, another small spacecraft had reached the asteroid belt between Mars and Jupiter, but the small spacecraft that this spacecraft explored recently did not look very different from a distance in appearance, but in fact, the two spaceships have essential differences, and if you look closely, you will find that there is still a big gap between these two small spaceships.

Among them, the spacecraft that explores the economy looks very beautiful on the outside, the whole spacecraft is an assembly line, and the very appearance is also coated with a layer of super reflective heat-resistant materials, and these materials have ultra-low heat absorption, which is mainly due to the extreme high temperature of Venus, so this exploration spacecraft must have the performance of high temperature resistance and high pressure resistance.

But this spacecraft to explore the asteroid belt is different, this spacecraft is covered with a thick layer of armor, and these armor is the hardest alloy that human beings can make at present, its hardness is more than twice that of diamond, the hardest object in nature on earth, reaching an unprecedented hardness of 260, it can be said that the ship's ability to resist strikes, especially for physical defense, is super strong, and even stronger than the defense of the most powerful space warship of the Ming Empire.

Moreover, the radar system and weapon system on this spaceship are also very advanced, although due to the limitation of the size of the spaceship, the attack power is much smaller than that of the most powerful warship of the Ming Empire.

However, because this spaceship was built in a very short time, and the most advanced space battleship of the Ming Empire was also built five years ago, the scientific and technological content of this space battleship is definitely better than those space battleships built a few years ago.

After all, the asteroid belt where the spaceship is going is a very dangerous place, there are hundreds of thousands of asteroids of different sizes and shapes working around the sun in the asteroid belt between Mars and Jupiter, and these asteroids are fatal to the spacecraft sailing in it, and a little carelessness may lead to the destruction of the ship.

Therefore, at this time, the main thing for the spacecraft to deal with is the various asteroids in the asteroid belt that pose a deadly threat to the spacecraft, so after the spacecraft enters the asteroid belt, it immediately turns on all the probes on the spacecraft.

Although there are hundreds of thousands of asteroids of different sizes in the asteroid belt, the asteroids in the asteroid belt should be like sand in the desert, very dense and slightly moving may cause violent collisions between asteroids.

However, in fact, this is not the case, because the asteroid belt revolves around the sun, and the asteroid belt is also very wide, its width is more than one astronomical unit, everyone knows that an astronomical unit is the distance between the sun and the earth, and the asteroid belt is equivalent to the distance between the sun and the earth, in such a large and empty orbit, even if there are hundreds of thousands of asteroids in the asteroid belt, in fact, its density is not very large, and whether it is Zhu Lei's previous life or the Ming Empire of this world, Spacecraft and probes have passed through the asteroid belt many times, but it is not what we imagined.

But even so, in fact, the spaceship sailing in the asteroid belt is still very dangerous, although the Ming Empire of this world, probes and unmanned spacecraft have crossed the asteroid belt many times, but there are also several unmanned spacecraft and probes in the asteroid belt asteroid destroyed, you must know that the Ming Empire of this world is definitely much more advanced in the aerospace field than Zhu Lei's previous life.

Especially in the past ten years, due to the strong demand for the unification of the Ming Empire, the Ming Empire has set its sights on space, so in aerospace and other fields related to the future of mankind, the Ming Empire has invested a lot of money, time and personnel to carry out research, not to mention that the Ming Empire also has a plane merchant like Zhu Lei who holds a super plane mall.

Although it is said that the Ming Empire has surpassed the vast majority of the primary civilizations in the plane mall in the aerospace field, there is no technology in the primary civilization of the plane mall, Zhu Lei spent a lot of money to buy it, after all, the technology required by the Ming Empire to upgrade the intermediate civilization is a very critical technology for the primary civilization, so the value of these technologies is very high.

And in many aspects of science and technology, in fact, the Ming Empire has made initial progress, and even relatively mature products have appeared, and these technologies are often very expensive in the outer plane mall, even if Zhu Lei puts all his net worth into it, he may not be able to afford it, after all, these are no longer ordinary technical materials.

In fact, at the beginning of Zhu Lei's acquisition of the Plane Mall, he thought that selling grain in the Mall was the most worthwhile, and the price of the grain in it was okay, but now he found that he was wrong, and it was very wrong, in fact, in the Plane Mall, except that the primitive civilization could only rely on selling primitive minerals and grain in exchange for energy coins, there was no other way to do it.

Although there is not much difference between the primary and intermediate stages of primary civilization, there is not much difference between selling scientific and technological products and selling food, but after reaching the advanced stage, the price of many scientific and technological products is also very high, especially those technologies and materials and products that are very important for the promotion of civilization.

For example, anti-gravity technology, energy technology, weapon technology, and special alloy smelting technology, these technologies are very expensive.

And even if these technologies are sold in the plane mall, they are very few, and most of the time even if you have energy coins, you can't buy such a technology, after all, as the core technology of civilization promotion, no one will show it, even if the civilization is promoted to the intermediate civilization period, such technology will not be easily taken out.

After all, these technologies are the most basic technology of a civilization, and in fact the most core technology, on the road of civilization development, in fact, they are all stepping on the technology of these technologies to develop, if these technologies are leaked, then the consequences are very serious, especially in the period of war, it is easy for the enemy civilization to seize the weakness and burn the entire civilization.

Even in the plane mall, although it is said that crossing the universe to another universe to conduct a plane war, if there is no portal, the possibility is very small, especially those universes with a complete cosmic will, but in fact this is not impossible, especially in those planes where the cosmic will is incomplete and the cosmic rules are not perfect.

Such a cosmic plane is actually very vulnerable to invasion by other universes, so these materials will be sold so little in the plane mall, and even as soon as they appear, they will be snatched away, so after such a long time, Zhu Lei understands very well that only taking the road of scientific and technological development is the king, and for those core technologies, even if they are in the super plane mall, he is not ready to sell them in the future.