For the first time, the European Space Agency mission will use the air brake method to approach and study the planet in the challenging conditions of Venus.
The feasibility of the European Space Agency's planned mission to Venus, a challenging aerobraking procedure to reduce orbital altitude that will test the spacecraft's thermal resistance limits.
The expected EnVision mission To be launched in the early 2030s, it will study the geological structure and atmosphere of the hellish planet Venus, which was once quite similar to Earth but has turned into a very burning world due to the greenhouse effect.
According to the European Space Agency. (ESA) To get EnVision into its target orbit 500 km above the surface of Venus, where even lead melts, thousands of passes through the planet's thick atmosphere will be made over two years.
"Thomas Vorin" ( Thomas Voirin, the mission's director of studies, said: "Invision, as it is now thought, cannot be left behind. The van-sized spacecraft, which will be launched on Europe's future Ariane 6 rocket, will have the ability to carry enough fuel to decelerate using It does not have its own propulsion and uses the air brake method instead, and by following a very elliptical orbit, it periodically reaches 130 km from the surface of Venus at the closest point and about 250,000 km at the farthest point.
The European Space Agency has already used the air brake method to slow down the gas orbiter "ExoMars" before entering its scientific orbit around Mars, but the atmosphere of Mars is much thinner than that of Venus and its gravity is much less, which affects the speed of the spacecraft. Orbiting affects it.
Vorin added: "Airbraking around Venus will be much more challenging than the ExoMars mission. The gravity of Venus is about 10 times greater than the gravity of Mars, and thus the spacecraft experiences speeds about twice as high as ExoMars when passing through the atmosphere, and heat is produced with the ratio of the second power of the speed.
European Space Agency. It briefly tested the airbrake around Venus during the final months of the Venus Express mission, which eventually drifted toward the planet and burned up in its atmosphere in 2014. But because the spacecraft was at the end of its mission, experts weren't worried about heat damage. Meanwhile, InVision is expected to explore Venus for at least four years.
Engineers are currently working on suitable materials that can withstand the extreme conditions of InVision's mission. In addition to the heat experienced during the air braking process, the spacecraft will also be exposed to a very high concentration of reactive atomic oxygen.
Atomic oxygen is a form of oxygen found in the upper layers of the Earth's atmosphere that consists of one oxygen atom. has been This atom is the enemy of all low-Earth orbit spacecraft and burned the heat shield on several NASA space shuttle missions in the 1980s.
Observations from previous Venus missions have shown that atomic oxygen in the upper layers of the Venusian atmosphere is in similar concentrations. There are concentrations around Earth.
According to the director of spacecraft studies, "the concentration is very high. "It doesn't matter much for one pass, but over thousands of passes, it starts to build up and lead to a level of atomic oxygen flux that we have to consider similar to what we experience in low Earth orbit, but at a higher temperature."
The European Space Agency hopes to have candidates for materials completely resistant to heat and concentration by the end of this year. atomic oxygen expected during Invision air braking.
According to experts, these materials must be resistant to erosion and also retain their optical properties, meaning they do not degrade or darken, and in Their thermal behavior should not be disturbed.
For the correct functioning of the delicate scientific instruments used in this mission, the regulated temperature must be maintained well, and also the scaling or gas escape that leads to local contamination should be prevented.
Focusing on Mars, which is potentially more habitable, Venus, sometimes called Earth's twin because of its similar size, has been largely dismissed by solar system explorers, but a Elah, which detected phosphine molecules in the planet's atmosphere in 2020, sparked a new wave of interest in Venus.
In addition to Europe, NASA also plans to send orbiters to this hot planet: the "Da Vinci" missions. +" (+DAVINCI) and "VERITAS" which are expected to be launched between 2028 and 2030.
Currently, only one Japanese spacecraft named "Akatsuki" is in orbit. It is orbiting Venus and studying the density of the atmosphere in an attempt to uncover the secrets of its harsh weather.
Photos: A graphic design of Europe's InVision mission to