Rocket fuel eating away at US, China nuclear weapons

Aging rocket fuel may be quietly crippling the world’s nuclear arsenals, according to a new report exposing the ticking time bomb inside both US and Chinese missiles.

This month, South China Morning Post (SCMP) reported that Chinese rocket scientists have discovered that the solid fuel used in intercontinental ballistic missiles (ICBMs) ages much faster than previously known, potentially rendering hundreds of missiles unusable.

Research conducted at China’s National Key Laboratory of Solid Rocket Propulsion in Xian revealed that significant changes in the fuel columns can occur within 30 years, making them unable to withstand the loads during flight. This finding could explain the frequent launch failures experienced by some nuclear powers in recent years.

The study, led by senior engineer Qin Pengju, found that while the aged propellant appeared stable during routine storage, it became significantly more brittle under high pressure. It mentions that the research focused on the solid fuel commonly used in ICBMs: ammonium perchlorate, aluminum powder and hydroxyl-terminated polybutadiene (HTPB) binder.

SCMP says the study’s findings suggest that the fuel’s ductility under pressure can be compromised after just 27 years, leading to possible rapid fractures during launch. It notes that the issue has raised concerns about the US’s declining nuclear deterrent capability, which relies on Minuteman III missiles manufactured in the 1970s and Trident II missiles that have been operational for nearly three decades.

Perhaps illustrating the unreliability of aging ICBMs, a failed Minuteman III ICBM test in November 2023 has heightened concerns about the US’s aging land-based nuclear arsenal. The unarmed missile was terminated during a launch from Vandenberg Space Force Base due to an anomaly.

While the Minuteman III as a whole is still considered a reliable weapons system, its subcomponents, such as the silo, electronics and warhead, are old and may have been neglected.

Asia Times has previously reported that the US faces mounting pressure to replace its aging Minuteman III ICBMs as delays and cost overruns plague its next-generation LGM-35A Sentinel program.

Budgeted initially at US$95.8 billion, the Sentinel’s cost has surged to an estimated $160 billion, forcing the Pentagon to justify the increase under the Nunn-McCurdy Amendment. Due to Covid-19 disruptions and inflation, production delays have postponed its deployment until 2029. As a result, the US Air Force must extend Minuteman III’s lifespan.

Aside from old delivery systems, Asia Times reported in January 2024 that the aging of plutonium pits in US nuclear weapons poses a significant challenge to the country’s strategic deterrent. Despite plutonium’s 24,000-year half-life, microscopic changes over time can affect the storage safety and explosive yield of nuclear weapons.

The US National Nuclear Security Administration (NNSA) has struggled to produce new plutonium pits, with current production capacity unlikely to meet the goal of 80 pits annually until 2030 or later. This shortfall is attributed to a post-Cold War culture of complacency, a lack of skilled workers and restrictive environmental regulations.

Existing pits, designed for older weapons, may not perform as required in newer systems, raising concerns about the reliability of the US nuclear arsenal.

Keeping the 1970s-era Minuteman III poses significant challenges. In a February 2014 RAND report, Lauren Caston and other writers mention that central to keeping the aging Minuteman III in service is the aging infrastructure and components that require continuous modernization to maintain operability.

Caston and others mention that while the Minuteman III Service Life Extension Program (SLEP) aims to incrementally modernize the system by replacing critical subsystems like guidance and propulsion, the incremental modernization approach is hampered by the obsolescence of original manufacturing processes and materials, forcing reliance on more expensive, modern substitutes.

Another significant operational constraint is the depletion of missile inventory due to annual test firings, which accelerated after 2017 when the rate increased from three to four tests annually. They say America’s missile stockpile could dip below required operational levels by 2030 without ramping up new production.

As the US struggles to keep the Minuteman III in service while justifying the Sentinel’s ballooning costs, Parth Satam mentions in a July 2024 article for The Aviationist that extending the Minuteman III’s life until 2050 is significantly cheaper, with past refurbishments costing only $7 billion for 450 missiles.

However, Satam points out that maintaining these vintage systems is technically challenging due to outdated documentation and a lack of knowledgeable technicians. He contrasts that to the Sentinel program, despite its $140 billion price tag and cost overruns, promising a modern, cyber-defendable command and control system.

Satam says the US Department of Defense’s (DOD) projected lifetime for the Sentinel, set up to 2075, is arbitrary and inflates costs. He says a more flexible timeline could make the Minuteman III extension more viable. However, he cautions about the risks of not modernizing, citing the need to address emerging threats from nuclear-armed competitors like China and Russia.

However, he notes the Sentinel’s development could also strain budgets, potentially impacting other key defense programs such as the Next-Generation Air Dominance (NGAD) fighter and B-21 Raider stealth bomber.

This situation raises concerns about reliability and deterrence amid growing threats from nuclear rivals. Unlike the US, China and Russia have aggressively modernized their nuclear arsenals, further exacerbating the US’s strategic dilemma as China is ramping up fissile material production and Russia showcasing nuclear brinkmanship in the Ukraine war.

While liquid-fuel systems may avoid problems associated with solid fuel, they bring challenges such as difficult-to-store propellants, design complexity, which opens up more points of possible failure, and the need to be fueled before launch, unlike solid-fuel missiles.

To illustrate these problems, Sidharth Kaushal mentions in an October 2024 Royal United Services Institute (RUSI) article that Russia’s efforts to replace the aging liquid-fuel R-36 Satan ICBM with the RS-28 Sarmat have faced significant challenges, highlighting issues within its missile production sector.

Kaushal says that the recent catastrophic failure of the Sarmat test in September 2024 underscores these difficulties. He notes that the failure, likely due to propulsion issues, caused extensive damage to the Plesetsk Cosmodrome.

He notes that the Sarmat, intended to replace the Soviet-era R-36, has experienced repeated delays and technical problems since its development began in 2013. The complexity of the new system’s propulsion and lighter structure have contributed to these setbacks.

Additionally, he mentions that the collapse of Russia’s cooperation with Ukrainian contractors, who previously maintained the R-36, has exacerbated the situation. He says Russia’s reliance on its Makeyev Rocket Design Bureau for the Sarmat’s development has not fully mitigated these issues.

Kaushal points out that the RS-28’s troubled history, including multiple failed tests and delays, raises concerns about the reliability of Russia’s silo-based ICBMs, which are crucial for its strategic deterrence. However, he says that despite these challenges, the Sarmat has been accepted into service, reflecting the urgency of replacing the R-36.