Solid and Cryogenic Fuel Technology

Utilizing Solid and Cryogenic Fuel Technology, North Korea recently test-fired a new intermediate-range ballistic missile (IRBM), marking the first instance of such a missile powered by solid fuel with a hypersonic warhead, capable of launching with minimal preparation.

What are Solid Fuel Missiles?

• Solid-fuel missiles are rockets that use a solid propellant, which is a mixture of fuel and oxidizer, packed in a solid cylinder (combustion chamber).
• The fuel and oxidizer are mixed into a fine powder and pressed into a solid cake.
• Once lit, the solid fuel will continue to burn until it is used up.
• Solid rocket engines are used on air-to-air and air-to-ground missiles, on model rockets, and as boosters for satellite launchers.
• The combustion produces more exhaust gas at high temperatures and pressure.
• The amount of exhaust gas that is produced depends on the area of the flame front and a variety of hole shapes can control the change in thrust for a particular engine.
• The hot exhaust gas is passed through a nozzle which accelerates the flow, and thrust is produced according to Newton’s third law of motion.
• Advantages over liquid-fuel missiles:
  • There is no need for fueling immediately before launch.
  • Easier and safer to operate.
  • Require less logistical support.
  • They are harder to detect and more survivable.
  • It can be stored for an extended period without degrading or breaking down, unlike liquid fuel.

What is Cryogenic Fuel Technology?

• Cryogenic fuels are liquefied gases that are stored at very low temperatures.
• They are used in rocket engines that use cryogenic fuel and oxidizer.
• Cryogenic fuels have a high energy density, but they require advanced insulation for storage and transportation.
• Cryogenic propellants include Liquid nitrogen, Oxygen, Hydrogen, Liquid helium, etc.
• Some rocket engines use regenerative cooling, by circulating their cryogenic fuel around the nozzles before the fuel is pumped into the combustion chamber and ignited
• The Indian Agni and GSLV rockets use liquid oxygen (LOX) and liquid hydrogen (LH2) as cryogenic propellants.
• Advantages of Cryogenic fuels:
  • The rocket needs to carry a lesser amount of cryogenic propellants.
  • This translates into a higher weight of payload it can carry.
  • Liquid propellants provide greater propulsive thrust and power.

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