More than half an hour later, the test results of the experimental samples came out.

"Li Suo, there is no change."

"Continue to ramp up stress testing." Li Xiang was not discouraged, after all, scientific experiments cannot be achieved overnight.

The experiments in the laboratory continued, and Huang Haojie was thinking about some things on the side.

The sizzling sound filled the entire laboratory, and as the pressure increased, the noise generated became louder and louder, and the people in the laboratory had to wear earplugs.

More than three hours later.

"The good news of Li is that the solid-state maintenance temperature of submetallic oxygen has increased."

"How much has it improved?"

"Rise to minus 41 degrees Celsius."

"How long can it be stored beyond the temperature?" Huang Haojie asked another question.

"In the range of minus 41 degrees Celsius and below 22 degrees Celsius, it can be held for about 16 minutes." The researcher replied with a look of adoration.

They had no clue for several months in the research institute, and Huang Haojie broke the deadlock as soon as he came, and had to let them bow and worship.

"Adding more pressure, I have a hunch that success is beckoning us." Li Xiang commanded.

"Okay."

The lab is busy again.

Huang Haojie looked at their experiment, and there might be no way to complete it for a while, so he beckoned to Li Xiang.

He typed on the display screen of the holographic bracelet: [You guys are busy first, I'll go to other research institutes to take a look, and send me a panda number if there are results.] ］

Li Xiang gestured with an OK gesture.

……

Leaving the noisy materials research institute, Huang Haojie took an electric car to the hydrogen and oxygen engine research institute.

Looking out the car window, there were red maple and kapok trees, and before I knew it, another year had passed.

With the expansion of Galaxy Technology, the scale of various research institutes has also expanded, and now the whole of Shanmei is either a factory or a research institute of Galaxy Technology.

The hydrogen-oxygen engine research institute he is going to is near the town of Shalang in Red Bay, more than 20 kilometers away from the Institute of Materials.

Galaxy Technology's Hydrogen and Oxygen Engine Research Institute was established very late, and was only established in November last year.

Of course, in front of the wealthy Galaxy Technology, the scientific research strength of the Hydrogen and Oxygen Engine Research Institute is now very good, and a large number of researchers from Dongdao have been added to it.

They are now tackling issues related to hydrogen-oxygen engines.

Huang Haojie was looking at the situation of the Hydrogen and Oxygen Engine Research Institute.

In fact, at present, the aerospace agencies or enterprises in various countries have different engine routes.

The engines of space rockets can generally be divided into: solid fuel rockets, liquid oxygen kerosene engines, liquid hydrogen and liquid oxygen engines, liquid oxygen methane engines, and nitrogen tetroxide/hydrazine engines.

The advantage of solid fuel is that it is easy to store and launch; The disadvantage is that the fuel is expensive and the specific impulse is small (the specific impulse is small, the load is small).

The advantages of liquid oxygen kerosene engine are high cost performance and high specific impulse; The disadvantages are also very obvious, the combustion chamber is prone to sintering, which is not conducive to the reuse of rocket engines.

The advantages of liquid oxygen and liquid hydrogen engines are high thrust and high specific impulse; The disadvantage is that liquid hydrogen is difficult to store and the production cost is high.

In addition, liquid hydrogen has caused many engineering difficulties due to low temperature, and if liquid hydrogen encounters air in the pipeline, the air will directly freeze and block the pipeline.

The density of hydrogen is extremely low, the molecule is very small, and where the molecule is small and other gases cannot penetrate, hydrogen can, so the hydrogen pipeline valve has put forward extremely high requirements for design and manufacturing.

At the same time, the hydrogen tank is large, but it is very light, which is not very friendly to the overall design.

In addition, hydrogen can penetrate metal parts, causing hydrogen embrittlement.

And the nitrous tetroxide/hydrazine engine, which is similar to a solid-fuel rocket, is not only expensive for fuel, but also Nima's, it is toxic! It is called poison.

At present, the most promising is the liquid oxygen methane engine.

Although the specific impulse of liquid oxygen methane is lower than that of the excellent hydrogen-oxygen combination, it is still higher than that of liquid oxygen kerosene, which makes this fuel oxidizer combination have practical value.

The boiling point of methane fuel tank is much higher than that of liquid hydrogen, close to liquid oxygen, and the molecule is larger.

Therefore, the fuel tank of the liquid oxygen methane rocket is about the same size as the oxygen tank, which saves a lot of trouble.

The vast majority of a rocket engine's design cost and most of its manufacturing cost is its turbo pump.

Because the density of hydrogen is too low, the number of revolutions required for the hydrogen pump is high, and the design is difficult, requiring a multi-stage pump to achieve the desired combustion chamber pressure.

Methane rockets, from fuel tanks, to pipelines, to turbine pumps, are all much less difficult. Its turbo pump is even one stage is sufficient.

Compared to kerosene rockets, the engine of the liquid oxygen methane combination is less prone to coking.

Not only is the gas generator temperature increased, but the pressure potential of the main combustion chamber is even greater. And when you use it again, you don't have to clean up.

Therefore, at present, aerospace agencies or enterprises in various countries are developing liquid oxygen methane engines. Blue Origin is engaged in liquid oxygen methane engines, Elon?? Musk's SpaceX next-generation heavy-lift rocket also chose a combination of liquid oxygen and methane.

Of course, hydrogen-oxygen engines are also very competitive.

Also, about the Saturn V.

Although it has the most powerful engine in history, its principle is not the most advanced.

THE COMBUSTION CHAMBER PRESSURE OF THE SATURN V F1 ENGINE IS LESS THAN 10 MEGAPASCALS (I.E., 100 STANDARD ATMOSPHERES), WHICH IS NOT GOOD FOR IMPROVING PERFORMANCE, AND THE ENGINE CHAMBER PRESSURE OF THE GAS GENERATOR CYCLE IS GENERALLY LOW, AND THE ENGINE CHAMBER PRESSURE OF SPACEX IS NOW LESS THAN 10 MEGAPASCALS.

The high room pressure should adopt more advanced principles, such as the staged combustion cycle engine used by Mao Xiong and Dongtang, and the ultimate room pressure has reached 25 megapascals (250 atmospheres).

At that time, due to the lack of thorough research on the principle of kerosene rocket engines, it was believed that the room pressure of kerosene engines could not be increased, so NASA abandoned the kerosene staged combustion cycle engine.

The real reason is that the crude oil they use is problematic, and the kerosene produced has too high sulfur content, which causes the engine to be damaged at high chamber pressure.

Due to the low sulfur content of the crude oil produced in the oilfield, Mao Xiong easily realized the high room pressure kerosene engine.

Therefore, when engaging in scientific research, the luck factor is very large, and the marine plankton hundreds of millions of years ago determined the development direction of rocket science later.

Later, in the 70s, NASA fully switched to recyclable spacecraft and multiplexing rocket engines, and in principle, hydrogen-oxygen engines were the most suitable for reuse.

As a result, there was a staged combustion cycle hydrogen-oxygen engine represented by the Space Shuttle SSME engine.

In order to develop multiplexed spacecraft, Mao Xiong also embarked on this road, and the RD0120 of the Energy rocket is a high-thrust hydrogen-oxygen engine of the same class as SSME.

As for why, NASA now does not use its own hydrogen-oxygen engines, but the ones of the Woolly Bear.

The main thing is that there is a problem with their technical route, in fact, in a strict sense, it cannot be said to be a problem.

But when they switched from kerosene liquid oxygen engine to hydrogen oxygen engine, this turn was too urgent, and it is impossible to get up and down now.

It is commonly known as the step is too big, and it hits the egg.

For Galaxy Technology, the storage and process is very simple due to the possession of submetallic hydrogen.

If the research and development of submetallic oxygen goes smoothly, it will be like a tiger for hydrogen and oxygen engines.

The problems facing the hydrogen-oxygen engine research institute are mainly the problem of turbocharged pumps.

Only by solving this problem can the recyclable hydrogen-oxygen engine be almost completed.