Vietnamese PhD seeks to reduce material temperature to protect spacecraft.

Dr. Le Thi Quynh Trang and scientists in Japan have discovered a method to reduce heat flow through materials, helping to protect the surfaces of spacecraft and satellites.

The study was published in Nature by Dr. Trang from the Institute for Advanced Technology Research and Development at Duy Tan University and professors from Japan. The researchers believe that reducing electron and ion thermal flux is one of the important issues contributing to the protection of satellite and spacecraft surfaces.

Speaking to VnExpress , Dr. Trang explained that when electrons and ions are at high temperatures, they easily move and collide with metal surfaces. As a result, the metal surface can be damaged. The research team used an external magnetic field, created by the current flowing through the heating wire. A plasma flow model, comprising electrons and ions in a small region, was established using two spatial dimensions and three coordinates for velocity to determine the effect of the heating wire on the particles and the thermal flux.

Plasma simulations are limited by a vacuum. Image: Research team

Dr. Trang explained that when simulating the motion of plasma particles at the edge of the tokamak, the team found that the magnetic field could change the direction and intensity of the heat flux because electrons and ions rotate around the magnetic field lines. In particular, a concentrated magnetic field (one with maximum magnitude in the center and rapidly decreasing away from the center) can form magnetic mirrors. These mirrors help retain most of the plasma particles as they move across them, only allowing particles with sufficient velocity to escape the mirror and move outwards. Therefore, the high-energy particle flux is reduced before impact with the metal surface.

Explaining the use of a heating wire in their research, the team stated that the magnetic field generated by a conductor is inversely proportional to the distance from the wire; the further away from the conductor, the smaller the magnetic field. In other words, the conductor can create a concentrated magnetic field. Using electrical discharges can alter the magnetic field structure of the system, affecting the direction of particle flow. After careful study, the team concluded that high heat flux is significantly reduced at the metal surface when using electrical discharges.

The Crew Dragon spacecraft uses advanced materials to protect its surface. Photo: SpaceX.

Dr. Trang believes the research results are important and could become a potential candidate for reducing the flow of high-energy particles to metal surfaces, thereby shielding the surfaces of satellites and spacecraft from high-energy ion and electron streams. She optimistically predicts that this research method could soon be applied in practice. "The team will further investigate the feasibility of our proposed method when putting it into experimentation," Dr. Trang said.

Research into new materials and surface protection solutions for spacecraft and satellites is being pursued by many scientists. For example, NASA once used a self-peeling carbon fiber-coated heat shield to prevent a spacecraft carrying humans to Mars from burning up upon its return to Earth.

In 2021, Chinese researchers developed a novel type of two-layer polyimide nanocomposite membrane that could be used to more effectively protect the outer surfaces of spacecraft.

vnexpress.net