When entering a planet's atmosphere, a spacecraft experiences thermal loads that its protective shell must withstand. Its parameters depend on the flight conditions and the properties of the celestial body's atmosphere. Scientists from the Moscow Aviation Institute (MAI) have developed algorithms for calculating thermal protection, taking these factors into account. Alexander Bon, head of the small spacecraft project at the MAI Center for Space Technologies, spoke about the development. The software complex takes into account atmospheric density, spacecraft speed, and the angle of entry into the gas envelope.
On Mars, the atmosphere is thin, so it slows down the lander less effectively, although the spacecraft still experiences significant heating upon entry. On Venus, the impact of sulfuric acid droplets in the cloud layer must also be considered. Titan, Saturn's moon, has a different atmosphere — predominantly nitrogen, with an admixture of methane and complex organic compounds. Due to these differences, one cannot simply take a single thermal protection calculation and use it unchanged for any planet, the expert explained.
New optimization methods help to quickly select thermal protection parameters, taking into account the conditions of entry into a planet's atmosphere. If an engineer changes the material or flight trajectory, the program first provides an approximate result based on previously accumulated data, and then refines it using a full physical model. According to Alexander Bon, this reduces repeated calculations and saves supercomputer resources.
The performance of algorithms for calculating spacecraft thermal protection was tested in the laboratory
Scientists manufactured samples of multilayer panels simulating the thermal protection of a spacecraft wing and tested them in a vacuum chamber. There, conditions encountered by re-entry vehicles entering the dense layers of the Earth's atmosphere were reproduced. The discrepancy between the experimental results and the calculations, as reported, did not exceed 1.5%.
In the future, the team plans to expand the capabilities of the complex. In particular, engineers want to add thermal protection calculations with active elements, such as forced heat removal systems or materials with variable properties.