Chinese scientists found vulnerabilities in NASA's hypersonic weapons development software

According to the research team led by Professor Liu Jun (of the Hypersonic Technology Laboratory of the National University of Defense Technology of China), this small error between complex equations can lead to "inevitable results mistakes" when scientists simulate and analyze important problems, such as high-temperature wear. This information was published in the academic journal Acta Aerodynamica Sinica (China).

When an aircraft's speed exceeds Mach 5, intense friction with the air creates temperatures so high that they can ionize air molecules and cause chemical reactions. Mach 5 is a unit of speed, specifically 5 times the speed of sound.

These complex reactions can erode aircraft surfaces and change the temperature or density of the surrounding air. Inaccuracies in model data can have a profound impact on aircraft performance and safety.

The software Liu Jun mentioned is Vulcan-CFD, developed by NASA's Langley Research Center. Due to its potential use in the development of hypersonic weapons, Vulcan-CFD is subject to export controls with distribution limited to US borders.

Langley Research Center is one of NASA's oldest and largest research centers, located in Hampton, Virginia, USA.

The Langley Center focuses on research in the fields of aerodynamics, aeronautical engineering, materials, structures, control systems, information systems, Earth science, satellites, and space exploration.

Langley Center played an important role in many of NASA's achievements, including the Wright brothers' first flight, the Apollo program, the space shuttle, and the International Space Station.

Chinese researchers gathered information from an academic paper published in 2020, in which the NASA software development team introduced the operating principle of Vulcan-CFD and some of the key equations it uses .

Liu Jun and his colleagues said the software was 'famous' in the industry.

Having a laboratory in Hunan province, Liu Jun participated in research with scientists from the Chinese Army's Aerospace Engineering University in Beijing and the Aerodynamics Research and Development Center. learning force in Mianyang municipality in Sichuan province. These organizations have contributed to China's rapid development of hypersonic weapons technology over the past two decades.

The speed of US hypersonic weapons development lags behind that of China and Russia and is gradually being overtaken by a number of smaller countries. North Korea said it successfully tested the Mars 16B land-based hypersonic missile on April 3.

Meanwhile, the US Army's long-range hypersonic weapon (LRHW), similar to North Korea's missiles, failed consecutively in 2021 and 2022. The next three planned LRHW launches were all canceled or postpone.

These failures come at a high price. The US military has requested $1.28 billion in fiscal year 2025 alone from taxpayers "to deliver an experimental prototype with limited combat capability by 2024".

The US Congressional Budget Office blamed the slow progress on high temperatures.

'The fundamental challenge that remains involves managing the extremely high temperatures to which hypersonic missiles are exposed while traveling at high speeds through the atmosphere for much of their journey,' the Office wrote in a report after conducting a thorough investigation into US hypersonic weapons programs last year.

'Shielding hypersonic missiles' sensitive electronics, understanding how different materials behave, and predicting aerodynamics at sustained temperatures as high as 3,000 degrees Fahrenheit (about 1,649 degrees Celsius) requiring extensive flight testing. Tests are ongoing, but failures in recent years have slowed progress,' the US Congressional Budget Office said.

Liu Jun's team said it discovered a flaw in the equation used by NASA in Vulcan-CFD to describe the changes in concentration of various chemical components, such as oxygen and nitrogen, in the gas mixture at Vulcan-CFD. high temperature. This equation does not account for the mixing and transport of components due to small-scale turbulence that occurs when the temperature changes rapidly or fluctuates.

Due to the complexity of hypersonic aerodynamics, modelers may ignore some small-scale motions due to lack of understanding or calculations that are too complex to resolve.

Liu Jun's team said NASA's lack of attention to this detail led to the software's inability to accurately predict the chemical composition and temperature changes on the aircraft's surface, which could have a significant impact on software-based simulation, design, or analysis work.

NASA was one of the first organizations in the world to explore hypersonic technology.

The term 'hypersonic' was coined by Qian Xuesen, the 'father' of Chinese rocketry, when he was working at NASA as one of the three founding scientists of the Jet Propulsion Laboratory ( JPL) in 1946.

Scientists and engineers at NASA have conducted pioneering research and flight testing in this field, but in recent years, they have repeatedly suffered from budget cuts and brain drain.

JPL laid off 530 employees in February due to funding uncertainty.

Located in the city of Pasadena (California, USA), JPL is a non-profit research and development center funded by NASA. It is a center specializing in the field of jet propulsion.

JPL focuses on researching and developing spacecraft robots for scientific missions and space exploration.

In addition, JPL also participates in other projects such as developing robotics technology, Earth science and STEM education.

STEM is an acronym for a form of education aimed at a knowledge economy with a combination of four fields: Science, Technology, Engineering and Mathematics.

JPL has contributed to many important NASA achievements, including the Apollo program, the space shuttle, the International Space Station, and the probes to Mars, Jupiter, Saturn and other planets.