On the 24th, North Korea launched a so-called 'monster ICBM', the Hwasong-17.

The day after launch, North Korea's KCNA reported that the Hwasong-17 type rose to a maximum peak altitude of 6,248.5 km, flew a distance of 1,090 km for 4,052 seconds, and landed precisely in the planned waters in the high seas of North Korea's East Sea.

That's pretty much what our military detected.

If the Hwasong-17 is launched at a normal angle, the maximum range is expected to exceed 15,000 km, so it is analyzed that it will be able to put not only the mainland of the United States, but also all major continents such as Africa and Oceania within range.

The maximum range of the existing Hwasong-15 was about 13,000 km.

Here is a question we hear often.

Contents such as 'Which is better, our Nuri or the North Korean Hwasong-17' or 'The North Korean Hwasong-17 climbed 6,248.5km, why did our Nuri only go up 700km?'

Then, let's answer your curiosity by focusing on the explanation of Professor Young-geun Jang, Department of Aerospace Mechanical Engineering, Korea Aerospace University.

Nuri vs. Hwasong-17, single-stage engine thrust

First of all, the first-stage engine thrust of our Nuri is 300 tons.

It is a combination of four 75-ton thrust engines, and it is designed to put a 1.5-ton practical satellite in low orbit of 600 to 800 km by combining the two-stage engine composed of one 75-ton engine and the third stage, which is one 7-ton engine.

The key here is the 75-ton engine that goes into the first stage.

The clustering technology that binds the four engines together and moves them as one is also important, but the 75-ton engine is the key as it requires a 75-ton engine.

The first stage engine of North Korea's Hwaseong-17 is estimated to have a thrust of 160 tons.

(Some experts believe it to be 320 tons, but according to Professor Young-geun Jang's explanation, it was estimated at 160 tons. Related details will be detailed later.) The Hwasong-17 type single-stage engine contains two pairs of so-called 'Baekdu engines'.

The Baekdu engine is known to have been made by reverse engineering the Russian RD-250 engine by North Korea, so you can estimate its performance based on the RD-250 engine.

The RD-250 is the so-called twin engine.

Two engines are tied into a pair, and each pair of engines contains two nozzles.

The output of a pair of engines is 90 tons, so the thrust per nozzle is about 45 tons.

However, the Baekdu engine has a slightly lower thrust than this, so it is estimated that a pair weighs 80 tons and each nozzle weighs about 40 tons.

(The view that the Hwasong-17 type single-stage engine has a thrust of 320 tons is that the thrust per nozzle is 80 tons, but since the twin engines have an output of 80, Professor Jang Young-geun’s explanation, who viewed the thrust per nozzle as 40 It was judged to be reasonable and summarized as above.)

To summarize, if we compare only the thrust of the main engine, which is the core of the rocket, the Nuri has 75 tons and the Hwasong-17 type is 40 tons, so it can be said that the engine performance of the Nuri is good.

Then why, Hwasong-17 type climbed more than 6,200km, but Nuri could only climb 700km?

Entering orbit vs Reaching Top Altitude

To start with, the Nuri is a launch vehicle to put a satellite into a target orbit, whereas the Hwasong-17 is an intercontinental ballistic missile (ICBM) designed to strike distant enemies.

Comparing the maximum altitudes of the two projectiles is meaningless, as the objectives of the two projectiles are different.

The Hwasong-17 is an ICBM as North Korea says.

Although it is a test launch, if it is fired at a normal angle towards the United States, it is considered an attack toward the United States, and the missile is intercepted and in some cases, military retaliatory measures must be taken.

Even if you try to shoot in the other direction, the same goes for geographical restrictions.

Therefore, in order to show off the performance of the Hwasong-17, North Korea has no choice but to launch an extremely high-angle launch, and the result is a maximum altitude of 6,248.5 km.

On the other hand, Nuri is a space launch vehicle for launching satellites.

It's not about how far you can fly, it's about being able to put it on the right trajectory.

Professor Jang Young-geun of Korea Aviation University explains that there is no reason why it cannot go higher if the satellite payload is reduced and it shoots like North Korea.

So, can our projectile technology be superior to North Korea and do it?

"Experience is important for projectile technology"

After the first launch of our Nuri, North Korea downplayed the Nuri as a failure through external propaganda media.

Of course, it is true that the 3-stage engine did not do its job, but seeing that North Korea showed a similar reaction to the successful launch of our submarine-launched ballistic missile and SLBM, it seems that we did not intend to properly evaluate our technology in the first place.

However, it is projectile technology that does not tolerate even the slightest mistake.

At the time of the first launch of the Nuri ship in October of last year, the final three-speed engine turned off 46 seconds earlier than planned, and the final success was unsuccessful.

Investigation revealed that the helium tank in the oxidizer tank broke out of the fixture and damaged the helium pipe, and the leaked helium cracked the oxidizer tank and the oxidizer was not supplied properly.

Projectile technology is a state secret, so no country can easily tell you about it.

Even if you refer to another country's technology by reverse engineering, you can't secure it without trying it yourself.

This is because 'experience' is essential in projectile technology.

In that respect, experts estimate that North Korea is one step ahead of us in overall projectile technology.

North Korea has been working hard to develop missile technology since the 1960s.

Korea is also planning to accumulate projectile technology through numerous challenges, from the Naro to the Nuri to the launch of the lunar probe in 2030.

In particular, solid fuel that could not be used, which was tied to the Korea-US missile memorandum of understanding, became available for use in the production of projectiles from May of last year.

It is a time when investments and efforts commensurate with the national status must follow, even if it is not North Korea.