Europe’s planned Venus exploration mission will rely on difficult atmospheric braking to lower its orbit, which will test the spacecraft’s materials’ thermal elasticity to its limits.
EnVision missionexpected to be launched in early 2030, will study the geology and atmosphere VenusThe infernal planet that might one day be Just like the earth But he turned into a burning hostile world because of a fugitive Global Warming.
To get EnVision into its target orbit, 310 miles (500 km) above Venus’ surface (which is so hot that lead melts), it would take thousands of passes across The dense atmosphere of the planet Over two years, the European Space Agency (ESA) said in a statement (Opens in a new tab).
“Vision as it is currently envisioned cannot take place without this long phase of atmospheric braking,” Thomas Voeren, director of the EnVision study at the European Space Agency, said in the statement.
Related: How did Venus turn into hell, and how did the Earth become after that
The truck-sized spacecraft, which will launch the future of Europe Ariane 6 The rocket, however, would not be able to carry enough fuel to slow itself into the orbit of Venus using onboard thrust. Instead, it would use the atmospheric braking procedure and follow a highly elliptical orbit that periodically takes it to within 80 miles (130 km) of the surface of Venus at its closest point and about 155,000 miles (250,000 km) from the planet at its farthest point.
The European Space Agency (ESA) has previously used air braking to slow down ExoMars Track the orbital gas before it enters its scientific orbit around it Mars. But the atmosphere of Mars is much thinner than that of Venus gravity Much lower, which affects the speed of the orbiting spacecraft.
“Atmospheric braking around Venus will be more challenging than the Trace Gas Orbiter system,” Voeren said. “The gravity of Venus is about 10 times higher than that of Mars. This means that velocities are twice as fast as the speeds of the TGO the spacecraft will experience as it passes through the atmosphere, and heat is generated as a cube of velocity.”
The European Space Agency (ESA) briefly tested atmospheric braking around Venus during the last months of Venus Express The mission, which eventually spiraled toward the planet and burned up in the atmosphere in 2014. Since the Venus Express was already at the end of its mission, spacecraft controllers didn’t worry about heat damage to the spacecraft. On the other hand, EnVision is expected to explore Venus for at least four years.
The engineers are already busy preparing the right materials that will enable EnVision to withstand the harsh conditions. In addition to the heat exposed during air braking, the spacecraft will also be exposed to very high concentrations of highly reactive atomic oxygen. Atomic oxygen is a form of oxygen found in the upper layers of Earth’s atmosphere, which consists of one oxygen atom. Atomic oxygen is the enemy of all low ground Orbital spacecraft, thermal blankets burned on several NASA Space ship Missions in the eighties.
Observations made by previous Venus missions have shown that atomic oxygen is present in the upper layers of Venus’s atmosphere in concentrations similar to those around Earth.
“The concentration is very high. With one pass, it doesn’t matter much, but over thousands of times it starts accumulating and ends up with a level of atomic oxygen flux that we have to take into account, which is equivalent to what we experience in low Earth orbit, but at degrees,” said Fueren. higher temperature.
The European Space Agency is currently testing the materials for their ability to withstand both heat and the expected atomic oxygen concentration during EnVision’s atmospheric braking and hopes to have some candidate materials selected by the end of this year.
“We want to verify that these parts are resistant to corrosion, and also maintain their optical properties — meaning that they do not degrade or darken, which could have indirect effects in terms of their thermal behavior, because we have precise scientific instruments that must maintain a temperature of Specific.” “We also need to avoid precipitation or outgassing, which leads to pollution.”
Venus, sometimes considered Earth’s twin due to its similar sizes, has been somewhat marginalized recently. Solar System Explorers are becoming favored with potentially more habitable Mars (and which is more likely to harbor traces of life). But the 2020 study revealed Molecules that can be traces of living organisms Sulfur-rich clouds on the planet have sparked a new wave of interest in Venus.
In addition to Europe, NASA plans to send orbiters to the super-hot planet: The DAVINCI + AND VERITAS MISSIONSwhich is expected to be launched between 2028 and 2030. Currently, the only Japanese spacecraft Akatsukiorbiting the planet Venus, studying its dense atmosphere in an attempt to unravel the secrets of its harsh climate.