North Korea says it successfully tested solid-fuelled rocket motor, why does it matter?

Pyongyang has conducted a successful test of a solid-fuelled rocket motor and Kim Jong Un observed the test whilst smoking a cigarette, reported North Korea's state run news agency called Korean Central News Agency (KCNA). Two questions arise now - one, what is a solid-fueled rocket motor and two, why is this development significant. Let's address the second question for starters. US' primary ICBM (Inter Continental Ballistic Missile) Minuteman III relies on the power of 3 solid-fueled rocket motors. A solid fuelled ICBM can be launched faster than a liquid fuelled one, as per experts quoted in a CNN report.

This is significant because it means that the target nation will have less time to react to the incoming ICBM. Leif-Eric Easley, a professor at Ewha University in Seoul, said to CNN that “if North Korea’s high-thrust solid-fuel motor ground test at Sohae is nearly as successful as they claim, it is a significant step for the country’s nuclear-capable missile development”. To put it simply, sold-fueled rockets are the state of the art in missile technology. Assuming North Korea's media is not exaggerating about the success of the missile test, the next challenge will be successfully integrating the solid-fueled engine with an ICBM.

Pyongyang's rationale 

“That, my friends, is the first stage of a solid propellant ICBM," Jeffrey Lewis, director of the East Asia Nonproliferation Program at the Center for Nonproliferation Studies said, according to the CNN report. At the macro level, what does this mean? Ankit Panda, a senior fellow in the nuclear policy program at the Carnegie Endowment for International Peace said that North Korea is turning into a "prominent operator of large scale missile forces". John Mearshiemer, the preeminent realist foreign policy thinker, believes that Kim Jong Un will continue to pursue advancements in its nuclear missile programme because Pyongyang believes Libyan dictator Muammar Muhammad Abu Minyar al-Gaddafi made a mistake when he ended his nation's nuclear weapons programme. 

The underlying assumption is that if Gaddafi didn't end his nation's nuclear weapons programme, his fate would have been different. Pyongyang believes nuclear weapons are the only deterrent it has to ensure security. North Korea enjoys the backing of China and support of the Chinese people. Back in 2008, when US Senator Mitt Romney visited Beijing for the Olympics, he remarked how surreal it was to see all the Chinese nationals in the stadium cheer loudly for North Korea. 

What is a solid-fueled rocket motor? 

Now, let's address the first question - what is a solid-fueled rocket motor? A solid-fueled rocket motor is a type of rocket propulsion system that uses solid fuel as a propellant. Solid rocket motors are used in a wide range of applications, including military missiles, space launch vehicles, and amateur rockets. Solid rocket motors are simpler and more reliable than liquid-fueled rocket motors, which require a complex system of pumps and valves to deliver the fuel and oxidizer to the combustion chamber. They can be stored for long periods of time without the need for maintenance or refueling, making them well-suited for military applications.

Solid rocket motors consist of a solid fuel grain, an oxidizer, and a casing. The fuel grain is typically made of a mixture of a fuel and a binder, which holds the mixture together and allows it to burn slowly and evenly. The oxidizer is a chemical compound that provides the oxygen necessary for the fuel to burn. The casing is the outer shell of the rocket motor, which contains the fuel and oxidizer and provides structural support.

When the rocket is ignited, the fuel and oxidizer are ignited, producing hot gases that expand rapidly and produce thrust. The hot gases are expelled through a nozzle at the back of the rocket, producing the thrust that propels the rocket forward. Solid rocket motors can be designed to burn at different rates and to produce different levels of thrust, depending on the specific requirements of the application. They are typically used in combination with other types of rocket propulsion systems, such as liquid-fueled rocket engines, to provide the necessary thrust and control for a spacecraft or missile.

Advantages of solid-fueled rockets in ICBMs

ICBMs use both solid-fuelled rocket motors and liquid-fuelled rocket motors. Solid-fuelled rocket motors are considered much more advanced. There are multiple reasons for this - 

Simplicity: Solid-fueled rocket motors are simpler and more reliable than liquid-fueled rocket motors, which require a complex system of pumps and valves to deliver the fuel and oxidizer to the combustion chamber. This makes solid-fueled rocket motors less prone to failure and easier to maintain.

Storage: Solid-fueled rocket motors can be stored for long periods of time without the need for maintenance or refueling, making them quite suited for military applications such as ICBMs. Liquid-fueled rocket motors, on the other hand, must be regularly refueled and maintained, which can be logistically challenging in a military setting.

Readiness: Solid-fueled rocket motors can be ignited quickly and easily, making them attractive for use in military situations where rapid response is necessary. Liquid-fueled rocket motors, on the other hand, require a longer startup process and are not as readily available for immediate use.

Weight: Solid-fueled rocket motors are generally lighter and more compact than liquid-fueled rocket motors, which can be an important consideration for missiles that must be launched from a mobile platform.

However, it is worth flagging that ICBMs powered by solid-fueled rocket motors have some downsides as well. They do not provide as much thrust, which can limit the range and payload capacity of the missile.