The performance of polyimide can be said to be very excellent, in the range of minus 200-300 degrees, can work very well, and the mechanical properties are excellent, it is currently one of the organic polymer materials that can be used in light sails and has the best comprehensive performance.

At the same time, polyimide also has a very good property, that is, it is very light.

According to Newton's second law, the lighter the mass of an object with the same magnitude of force, the greater the acceleration and the easier it is to be accelerated.

Especially when everyone wants the spacecraft to reach close to the speed of light, it is also necessary to consider the possibility of mass increase due to relativistic effects.

So even if we reduce the mass of the solar sail even a little bit, the benefits we can get are very huge, which is why the researchers made the solar sail so thin.

Although there are a lot of cosmic engine technologies in Ye Fan's black technology system, whether it is a curvature engine or an engine that travels faster than the speed of light, it is not something that can be played with by the current level of science and technology of human beings.

Therefore, the solar sail, a non-working fluid engine, is currently an important means for human beings to fly out of the solar system, and even for long-distance interstellar navigation.

The sunlight is constantly radiating outward, so it is indeed a little difficult to get close to Mercury, and Ye Fan's initial plan is to install a solar sail on the mining spacecraft, so that it can reach a very high speed, and then let the mining spacecraft fly directly to Jupiter.

Jupiter's gravitational pull, also known as the "gravitational slingshot", is then used to throw the mining spacecraft directly towards Mercury's location.

Planets are not stationary, they carry huge angular momentum in both rotation and revolution, in the overall angular momentum of the solar system, the sun's own angular momentum accounts for only 2%, and the other 98% of the angular momentum is in the hands of the stars around the sun.

When the mining spacecraft cuts into the orbit of the planet, it also shares a part of the angular momentum of the planet, and the transferred angular momentum is reflected in the change in the velocity of the spacecraft as it flies into the gravitational field of the planet.

Using the Sun as a reference, the speed of the spacecraft flying through the stars at this time not only changes direction, but also increases in size.

Because according to the law of conservation of energy, the kinetic energy increased by the spacecraft is also the kinetic energy reduced by the planet, but the kinetic energy of the planet is too large, and the kinetic energy shared by a small spacecraft is only a drop in the bucket compared to it, and it will not affect the planet in any way.

It's like using wind power to generate energy from the flow of air without worrying about the wind stopping.

Therefore, the gravitational slingshot and the solar sail are feasible for both sailing within the solar system and interstellar voyages after leaving the solar system.

Although the electromagnetic propulsion engine can be propelled in a vacuum, the fatal disadvantage of this engine is that the power consumption is very terrifying.

The power consumption of this thing in a vacuum is more than fifty times greater than that of an ion engine.

Therefore, the electric propulsion engine needs a lot of electrical energy, but if the electric energy consumption of the electric propulsion engine is to be met, it is inevitable to make the battery bigger, and after the battery is bigger, the volume of the spacecraft will increase accordingly.

In this way, you will fall into the previous "paradox" again.

So this is also why Ye Fan is engaged in solar sails.

Unless Ye Fan can build a spaceship of the size that houses a heavy nuclear fusion reactor, and when sailing, he will constantly dig ore from the surrounding asteroids to replenish energy, and then drive the electric propulsion engine to sail in the interstellar.

However, before the formal integration of global resources, building such a large spaceship is tantamount to a dream. A small bookstore

The polyimide that makes up the solar sail, although it is already very light, shows from the technology of the system exchange that polyimide is not the best choice.

"Look, that's what makes our solar sails different from foreign ones, and we've found a new material, also known as a solar sail."

"Graphene."

Ye Fan's words fell, and the audience was in an uproar.

You must know that graphene is not unusual, but most people associate it with batteries, after all, graphene can indeed increase the capacity of batteries.

However, if graphene is simply used to increase power storage, it is inevitably too wasteful.

"This is our latest graphene, and its microstructure is that carbon atoms are connected to each other in a hexagonal shape, so its performance will be very amazing."

Subsequently, Ye Fan transmitted a research data to the holographic projection.

Su Ying also nodded at this time, although she is not a materials scientist, she is not unheard of graphene.

"This kind of material is really possible, after all, even if we have the corresponding technology, all materials can be compressed to the atomic level, but their strength will not be guaranteed.

But graphene does not seem to have such concerns, and its microstructure allows it to be very strong at the atomic scale.

When we were designing spacecraft, we also investigated graphene, so I also knew about graphene. Su Ying said.

"Well, about this kind of graphene, a foreign research team has created a miniature light sail with a diameter of only three millimeters, but a mass of less than a quarter of a gram.

They then placed the sail in microgravity and irradiated it with laser illuminators ranging from 0.1 watt to 1 watt to test its performance. ”

Later, Ye Fan uploaded another picture, which shows the latest graphene miniature light sail created by SCALE nanotechnology.

The final experimental results showed that the performance of this light sail was very good, and the expected effect was achieved.

"Of course, they are limited by the level of science and technology, and they can only do this at present, and it is difficult for them to make much breakthroughs in a short period of time, but we Datang Technology,

However, it is possible to make a solar sail with atomic thickness, which is much more advanced than that of foreigners, limited by production and practical application problems, it is still impossible to have a diameter of more than one kilometer long graphene solar sail board.

However, we are working on a solar sail with a diameter of 300 meters and a width of 200 meters, and its mass is not even a kilogram, but it is limited by the area, so even if it is folded, it will take up a lot of space. ”

Ye Fan projected a graphene solar sail on the table, and the elites present were surprised by Datang Technology's strong scientific research capabilities and strong industrial capabilities.

Not only has the lithography machine been developed, but also the atomic-level graphene has been made, if the latter can be realized, then for interstellar navigation, human beings really have the ability to take the first step.