In the early 2030s, the European Space Agency intends to plant a probe deep into the overwhelming atmosphere of Venus, a brutal planet that constantly burns at 462 degrees Celsius (864 degrees Fahrenheit), contains essentially zero water vapor and emanates a gravitational force. 90% stronger than Earth’s.
Or as NASA puts it, “Venus today is a hellish world.”
This poses a bit of a dilemma: How do you get a man-made spacecraft to not only withstand the incomprehensible dangers of Venus, but also navigate its lower atmosphere and gather valuable information without getting damaged? Well, according to the agency’s recently released game plan for its mission, called EnVision, the key is “aerbraking.”
“Flying in one [Ariane 6 rocket]we cannot afford all the extra propellant that would be needed to lower our orbit,” EnVision director of studies Thomas Voirin said in a statement Friday.
Here’s what’s going down.
First, the spacecraft will be injected into the orbit of Venus at a very high altitude, approximately 250,000 km (155,343 miles), Voiron explained. Then, to bring this craft to its final destination just 130 km (81 miles) from the planet’s surface, the craft will steadily shrink over about two years with thousands of repeated passes through the Venusian upper atmosphere.
Finally, the EnVision probe will settle into its final orbit, where it will image and map this toxic world with unprecedented precision. In addition, ESA says, it will take incremental science measurements as it descends, such as a polar orbit at 500 km altitude.
Artist’s impression of the spacecraft from ESA’s EnVision mission.
ESA/VR2Planets/Damia Bouic
ESA’s aerobraking concept has been tested before, such as with the agency’s ExoMars Trace Gas Orbiter mission. Near the red planet, it was a success.
However, “aerobraking around Venus will be much more difficult,” Voirin said. “The gravity of Venus is about 10 times higher than that of Mars. This means that the spacecraft will experience velocities about twice that of TGO as it passes through the atmosphere.”
On top of that, there will also be the obstacle of battling Venus’ giant concentration of highly reactive atmospheric atomic oxygen, which can damage the craft, as well as an extreme amount of heat surrounding the probe, because the heat generates exponentially along with speed.
“We want to check that these parts are resistant to erosion, and also maintain their optical properties, that is, they do not degrade or darken, which can have side effects in terms of their thermal behavior, because we have delicate scientific instruments that must maintain a set temperature,” said Voirin. “We also need to avoid flaking or outgassing, which leads to contamination.” Where EnVision goes, even lead becomes liquid.
EnVision candidate materials exposed to atomic oxygen in the laboratory.
IS IN
Notably, ESA also tried aerobraking with its previous Venus mission, called Venus Express, but employed the mechanism toward the spacecraft’s end-of-life sequence. He just burned to death.
This cannot happen with EnVision.
What will ESA’s Envision look for?
With the proposed mission, ESA’s hope is to maintain a spacecraft in deep Venusian orbit, so that it can help address long-standing questions surrounding the pale yellow realm. This includes things like whether Venus could have hosted an ocean or perhaps sustained life.
In fact, over many years a host of other space probes have tried to solve these mysteries: ESA’s Venus Express, of course, but also many of NASA’s missions, which have made stops close to Venus in the way to their main destinations. .
In the coming years, NASA also plans two Venus-specific missions called Davinci and Veritas. With a successful aerobrake, EnVision will complete this modern trio of Venus explorers.
There is also a very surprising question posed by Venus that EnVision could help answer. It is the timely concern of whether this abandoned world offers us a glimpse of the future demise of the Earth.
Venus is very similar to Earth, but so different.
NASA/JAXA/ISAS/DARTS/Damia Bouic/VR2Planets
“Many of the same tools we use to model climate change on Earth can be adapted to study the climates of other planets, both past and present,” said Michael Way, a researcher at the Goddard Institute for Space Studies. from NASA, in a statement. “These results show that ancient Venus could have been a very different place than it is today.”
Although Venus is now considered absolutely miserable, with a suffocatingly thick, carbon dioxide-dominated atmosphere and shockingly high temperatures, many experts believe that it formed from ingredients similar to Earth’s when our system came together solar Venus may have had a thin atmosphere and a few bodies of water, and generally appears to be our planet’s cosmic twin.
But because of what is called the “runaway greenhouse effect” on the planet, things changed.
Simply put, the greenhouse effect refers to the idea that Venus’ oceans evaporated over time, dumping water vapor into the atmosphere, which trapped too much heat. All that heat led to more evaporation from the ocean, which trapped more atmospheric heat… and…
Yes.
Could this also be what will one day happen to Earth? Especially considering that climate change is intensifying due to human activities like burning coal and shoveling CO2 into the atmosphere?
“Venus will help us understand what happens when the greenhouse effect is really extreme,” Hakan Svedhem, project scientist for ESA’s Venus Express mission, said in a statement. “However, it is not a good example of what will happen to Earth due to human activities. Life on Earth would disappear due to extreme temperatures long before reaching even half the concentrations of carbon dioxide from Venus!”
But hopefully, we won’t even come close to 30% of Venus’ terrifying levels.