Missile fuel technology plays a crucial role in the propulsion systems of missiles, influencing their range, speed, and overall performance. Various types of missile fuels have been developed over the years, each with its unique characteristics and applications. Read here to learn more.
North Korea has test-fired a multiple solid-fuel intercontinental ballistic missile (ICBM), since 2023, enhancing its launch capabilities with quicker preparation.
Solid-fuel tech offers advantages like safer and swifter operation, evading detection, and surviving better than liquid-fueled missiles.
Historically, China and the US advanced solid fuel, while North Korea, China, and South Korea have developed smaller versions.
Missile Fuel Technology
Missile systems are generally based on Solid fuel, liquid fuel, or cryogenic fuel technology, with few other variants in the mix.
Liquid Rocket Propellants
Liquid rocket propellants are commonly used in missile systems and are characterized by liquid fuel and oxidizer components. They offer precise control over thrust and can be throttled or shut down if necessary.
- Hypergolic propellants ignite spontaneously upon contact with each other, simplifying the ignition process.
- Common hypergolic pairs include unsymmetrical dimethylhydrazine (UDMH) and nitrogen tetroxide (N2O4).
- Scud-B and Scud-C missiles use hypergolic propellants.
- Cryogenic fuels are stored at extremely low temperatures, providing high energy density.
- Requires advanced insulation for storage and transportation.
- The Indian Agni and GSLV rockets use liquid oxygen (LOX) and liquid hydrogen (LH2) as cryogenic propellants.
Storable Liquid Propellants:
- Storable liquid propellants, like UDMH and inhibited red-fuming nitric acid (IRFNA), offer simpler logistics than cryogenic options.
- Suitable for military applications due to ease of handling and storage.
- The Titan II, an intercontinental ballistic missile (ICBM), used storable liquid propellants.
Solid fuel technology
Solid rocket propellants consist of a mixture of fuel and oxidizer in a solid form. They are known for simplicity, reliability, and ease of storage.
- Composite propellants consist of powdered oxidizers and binders.
- Provide high energy density and simplicity in design.
- Space launch boosters like the Space Shuttle’s Solid Rocket Boosters (SRBs) used composite propellants.
- Consists of nitrocellulose (fuel) and nitroglycerin (oxidizer).
- Historically used in artillery and smaller missiles.
- Early tactical missiles like the German V-2 used double-base propellants.
Hybrid Rocket Propellants
Hybrid rocket systems combine features of liquid and solid propellants, with a liquid oxidizer and a solid fuel. They aim to merge the benefits of both propulsion systems.
Liquid Oxidizer and Solid Fuel:
- Combines the simplicity of solid fuel with the precise control of liquid oxidizers.
- Offers safety advantages over traditional liquid rocket systems.
- The SpaceShipOne suborbital spaceplane used a hybrid rocket motor with a liquid nitrous oxide oxidizer and a solid rubber-based fuel.
Some advanced missile concepts explore air-breathing propulsion, where the missile draws oxygen from the atmosphere during part of its flight.
- Operates efficiently at high speeds by compressing incoming air without the need to carry oxidizers.
- Requires initial acceleration before the ramjet can start functioning.
- The BrahMos cruise missile uses a ramjet propulsion system.
- Similar to ramjets but operate at even higher speeds.
- More efficient at hypersonic speeds.
- Hypersonic missiles like the X-51 Waverider utilize scramjet propulsion.
Fuel systems in Indian missiles
A few years ago, DRDO successfully tested the Solid Fuel Ducted Ramjet technology missile. In 2023, Astra Mark 3 with solid fuel ducted ramjet propulsion was put to test flight, enabling the missile to intercept airborne threats over a very long distance at supersonic speed.
- Agni ballistic missiles are Solid-fueled missiles.
- The Prahaar is a short-range, solid propellant, road-mobile ballistic missile.
- The BrahMos (PJ-10) is a short-range, ramjet-powered, single warhead, supersonic anti-ship/land attack cruise missile.
- The Prithvi missile family is liquid-fuelled.
Missile fuel technologies have evolved significantly, driven by the need for improved performance, range, and versatility in various military and space applications.
From liquid and solid rocket propellants to hybrid systems and air-breathing propulsion, each technology has its advantages and is tailored to specific mission requirements.
The continuous advancements in missile fuel technologies contribute to the development of more capable and sophisticated missile systems in the ongoing pursuit of enhancing defense capabilities and space exploration.
-Article by Swathi Satish