This is how black technology should be used

Chapter 100 Solid Fuel Rockets and Something Wrong
In fact, there are still many advantages of solid rockets.

First of all, it has a lot of thrust, huge!
The current liquid rocket engine with the highest thrust is a product of history. It was born decades ago, and it is long gone now.

One is the single-chamber liquid rocket engine F1 with the largest thrust ever produced by mankind, and its thrust at sea level is as high as 680 tons.

The other is the RD-170, the largest thrust rocket engine ever manufactured by mankind. Its sea level thrust has reached 806 tons, and even later derivative models can reach 846 tons.

It is said that there is also a model with a thrust of 1000 tons, but this is "under research".

But even with this liquid rocket engine under development, their stand-alone thrust still cannot beat the solid rocket engine.

Because whether it is a single solid rocket motor with a maximum thrust of 1379 tons of the space shuttle in history, or a solid rocket motor with a single thrust of 1600 tons of the "ready to take off" King Pigeon rocket SLS, their thrust far exceeds 1000 tons. !
Therefore, solid rockets are very suitable for use as boosters, which can provide powerful take-off thrust for the rocket.

Two such solid rockets plus some liquid rockets can easily increase the thrust by three to four thousand tons, enough to send more than one hundred tons of cargo into space.

The second is the convenience of launching solid rockets.

The fuel is poured after the solid rocket is produced, and there is no need to refill the fuel before launch. Therefore, compared with the liquid engine, the solid rocket needs to do less preparation work when it is launched. It can be said that it can be launched when it is set up.

Because of this convenience, the time to prepare for launch is relatively short, and it can be launched in a short time, which is suitable for emergency launch of satellites and...immediate launch of missiles.

In addition, it does not choose a launch site very much, does not need to go to a special launch site for launch, and does not need additional measures such as launch towers, diversion tanks, cooling spray systems, fuel filling systems, etc., and can be launched on-board and at sea.

Solid rockets are especially suitable for concealed and ambush missiles, with good maneuverability and concealment, strong battlefield survivability, and strong deterrence.

At the same time, solid rockets can also work underwater and are suitable for making submarine-launched missiles.

Cough, after all, rockets and missiles are similar in shape, and they are even more similar when solid fuel is used.

The third advantage of solid rockets is that they are simple in structure and do not require complicated internal structures. They only need to have a heat-insulating layer inside the solid shell and then pour fuel.

After the fuel is solidified, a channel is dug in the center of the fuel along the rocket axis, and then a certain shape is carved into the inner channel of the drug column, so that the rocket can burn quickly and stably in a large area to form a powerful jet after ignition.

The tail of the rocket is not a heavy and complicated engine, but a high-temperature-resistant nozzle.

In other words, the entire rocket is an engine.

This simple structure is much simpler to develop than liquid engines, so the development cost of solid rockets is much lower than that of liquid rocket engines.

Of course, the solid rocket motor does not only have advantages, otherwise it would not be used as a booster for super rockets, so it also has many disadvantages.

The first is that it burns for a short time and has a small specific impulse.

Although the thrust of the solid engine is large, the burning time is extremely short. The longest working time of a single-stage solid rocket is just over 2 minutes, which is far from enough for launching satellites.

For example, it took more than 8 minutes for the Long March 30B rocket to launch the low-Earth orbit spacecraft, while it took more than [-] minutes for the Long March [-] to launch the satellite in geosynchronous orbit.

Therefore, launching satellites with solid rockets often requires multiple stages in series, starting with three stages, launching to a higher orbit requires four stages, and a relay of one stage and one stage can succeed. However, many liquid engines now have two stages, and most of them are only three stages.

In addition, the thrust of the solid rocket is not adjustable, and the combustion is not very stable.

Once a general solid engine is ignited, it cannot be turned off in the middle, and it is difficult to adjust the thrust, which is not good for precisely controlled space launches.

The solid engine used by the missile has achieved a certain degree of thrust adjustment, but it is far less flexible than the liquid engine, but it is enough for the missile.

In addition, the combustion process of solid rockets is uneven and unstable, and the thrust is very small in the later stage. These are uncontrollable factors.

Finally, there is the issue of price. Although the research and development costs and difficulty of solid rockets are low, their manufacturing costs and difficulty are not low.

Because it is combined with the fuel when it leaves the factory, and senior technicians are required to manually carve the powder column.

The solid grain column is machine-processed in the early stage, but just like the metal casting blank parts need finishing, the solid rocket propellant also needs it, and the requirements are higher.

Engineers must use ultrasonic flaw detectors and magnifying glasses to carefully inspect every square millimeter of the grain, and must not miss any tiny cracks and tiny bubbles, otherwise it is very likely that the rocket will fail due to uneven engine fuel during launch.

However, it is very difficult to carve solid rocket propellant, and it is an irreversible process that cannot be repaired. If it is cut across the board, a little carelessness will cause too deep scratches, so that the entire powder column will be completely scrapped.

What's more dangerous is that solid rocket propellants are also roughly equivalent to "dynamite", their chemical molecular structure is extremely active, and the operator is like lying on a pack of explosives when shaping and engraving.

Once the tool accidentally touches the shell or the friction force is too large, electrostatic discharge occurs, which will instantly cause combustion or even explosion.

And this kind of thing happened, the master exchanged his life for extremely strict operating rules.

But... this is the shortcoming of conventional solid rockets in the past, and now the "future black technology" is here.

In terms of specific impulse, the specific impulse of conventional solid rocket fuel is below 300s, that of liquid oxygen kerosene and liquid oxygen methane is above 300s, that of liquid hydrogen and liquid oxygen is above 400s, and that of solid metal hydrogen is against the sky. 1700s.

Small specific impulse and low efficiency?
nonexistent.

As for how to reverse the attribute of burning out the solid fuel rocket once it is ignited, Li Future also has a way.

At present, some missiles using solid fuel can already be activated twice, that is, the kind that separates the grain column in advance, and then stops naturally after burning for a period.

If necessary, ignite the second grain.

If you want to light a fire a few times, you can just go to a few paragraphs.

However, this kind of "secondary ignition" rigid batch needs to be set in advance, and it cannot be changed in case of emergencies.

Later, there was a way to separate the combustion accelerant from the fuel. When the accelerant was cut off, the flame was turned off, and when the accelerant was opened, it would burn again.

It's just that in this case, the structure of the solid rocket becomes more complicated, and the structural complexity is on par with that of the liquid rocket, but the controllability is still not as accurate as others.

On the contrary, the Freedom Federation is vigorously researching the "electronically controlled solid propellant" technology, which is very promising.

The technical core of electronically controlled solid propellants is not "electric control", but "fuel". The Freedom Federation wants to develop a "high-performance electric propellant".

This kind of propellant is very sensitive to electric arc, and the ignition or extinguishment of fuel can be controlled through electrodes, and at the same time, the combustion speed of propellant can be adjusted through the change of voltage to control the energy output.

Once this technology is successful, the new solid-fuel rocket can take into account the original convenience properties of solid-fuel rockets and the precise control properties of liquid-fuel rockets.

Coincidentally, Li Future has very mature technology here.

Just when Li Future kept his ears to the outside world and engaged in scientific and technological research, people outside noticed something was wrong.

　Thank you Yehuxu for your reward~~Chapter 212 points

　　
　
(End of this chapter)