ICBMs age faster, changes in missile fuel columns shorten their lifespan: China

A study by Chinese rocket scientists has uncovered a critical issue with the solid fuel used in intercontinental ballistic missiles (ICBMs). Tests conducted at the National Key Laboratory of Solid Rocket Propulsion in Xian revealed that significant changes can occur in missile fuel columns within just 30 years, rendering them unable to withstand flight stresses, even though missile fuel is typically considered stable for over 160 years under standard storage conditions.

Missile failures linked to solid fuel degradation

The project team, led by senior engineer Qin Pengju, identified this issue as a key factor behind the frequent ignition and test launch failures observed in recent years. The findings of the study were published in the Chinese peer-reviewed Journal of Propulsion Technology.

Qin and his team concentrated their research on the solid propellant commonly used in these missiles, composed primarily of ammonium perchlorate, aluminum powder, and an HTPB binder. By subjecting the fuel to accelerated aging treatments at high temperatures for up to a year, they discovered that, although the aged propellant appeared stable during routine storage, it became notably more brittle under high pressure compared to fresh fuel, the South China Morning Post reported.

Qin's team emphasized the importance of the propellant's ability to withstand pressure loads during engine operation to maintain the structural integrity of the fuel grain. Their research showed that the propellant's ductility under pressure could deteriorate significantly in as few as 27 years.

The structure of solid fuel is highly complex, with certain components needing to fit tightly with the missile body, requiring the fuel to remain ductile under stress. During a launch, the pressure generated—around six megapascals—could lead to rapid fracturing of aged propellant, posing a serious risk to missile performance.

Nuclear deterrent missiles face setbacks

In November 2023, a Minuteman III ICBM manufactured by Boeing experienced flight anomalies, resulting in its self-destruction. Two months later, a Trident II missile launched from a British Royal Navy submarine suffered a similar failure. Both missile types are critical components of the nuclear deterrent forces of the US and its allies. Over 400 Minuteman III missiles remain in service, despite being manufactured in the 1970s, while the Trident II has been operational for nearly 30 years.

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The Minuteman III has shown repeated failures during inspections and tests, while the Trident II, despite a strong track record of reliability, suffered back-to-back launch failures. These incidents underscore growing concerns about the long-term effectiveness of these critical deterrent systems.

Meanwhile, the US military is conducting rigorous inspections and assessments to ensure the reliability of its nuclear weapons, investing nearly $10 billion to extend the service life of its Minuteman III missiles.

In comparison, China’s nuclear arsenal is smaller than that of the US and Russia, but the nation has introduced new missile types, including hypersonic weapons. Many of these missiles are mobile-launched from platforms like trucks or trains, enhancing their survivability in comparison to silo-launched systems like the Minuteman III.