In the early 2030s, the European Space Agency intends to place a probe deep into the crushing atmosphere of Venus, a brutal planet that constantly burns at an incredible 864 degrees Fahrenheit (462 degrees Celsius), contains almost zero water vapor and radiates a gravitational pull of 90 % stronger than that of Earth.
Or as NASA puts it, “Venus today is a hell of a world.”
This raises a bit of a dilemma: How do you get a human-made spacecraft to not only withstand the incomprehensible dangers of Venus, but also surf its lower atmosphere and gather valuable information while remaining unharmed? Well, according to the agency’s newly released plan for its mission, called EnVision, the key is “air suspension.”
“Flying on [Ariane 6 rocket]we cannot afford all the extra fuel needed to lower our orbit,” EnVision research director Thomas Voarin said in a statement on Friday.
Here’s what will drop instead.
First, the spacecraft will be injected into Venus’ orbit at a very high altitude, approximately 155,343 miles (250,000 km), Voiron explained. Then, to get that craft to its final destination of just 81 miles (130 km) from the planet’s surface, the craft will steadily decelerate over about two years with thousands of repeated passes through the upper atmosphere of Venus.
Eventually, the EnVision probe will be deployed to its final orbit, where it will image and map this toxic world with unprecedented precision. Plus, ESA says it will take science measurements gradually as it descends — like around a polar orbit about 500 km high.
An artist’s impression of ESA’s EnVision spacecraft.
ESA/VR2Planets/Damia Buick
ESA’s airdrop concept has been tested before, such as with the agency’s ExoMars Trace Gas Orbiter mission. Near the red planet was a success.
However, “airstop around Venus will be much more challenging,” Voirin said. “The gravity of Venus is about 10 times that of Mars. This means that velocities about twice those for TGO will be experienced by the spacecraft as it passes through the atmosphere.”
Beyond that, there will also be the obstacle of contending with Venus’s gigantic concentration of highly reactive atmospheric atomic oxygen, which could damage the craft, as well as the immense amount of heat consuming the probe, as heat is generated exponentially with speed.
“We want to check that these parts are resistant to erosion and also retain their optical properties – meaning they don’t deteriorate or darken – which can have side effects in terms of their thermal behavior because we have delicate scientific instruments that have to to maintain a set temperature,” Voirin said. “We also have to avoid flaking or off-gassing, which leads to contamination.” Where EnVision is going, even lead becomes liquid.
EnVision candidate materials exposed to atomic oxygen in the laboratory.
ESA
It should be noted that ESA also tried an airstop with its previous mission to Venus, called Venus Express – but used the mechanism towards the spacecraft’s end-of-life sequence. It just burned and died.
This cannot happen with EnVision.
What will ESA’s Envision be looking for?
With the proposed mission, ESA’s hope is to keep a spacecraft in deep orbit around Venus so that it can help address long-standing questions surrounding the pale yellow realm. This includes things like whether Venus once had an ocean or perhaps supported life.
In truth, over many years a host of other space probes have attempted to solve these mysteries – ESA’s own Venus Express, of course, but also many of NASA’s missions that have made stopovers near Venus en route to their main destinations.
In the coming years, NASA also has two Venus-specific missions planned, called Davinci and Veritas. With some successful airstop, EnVision will complete this modern trio of Venus explorers.
There’s also a super striking question raised by Venus that EnVision can help answer. It is a timely concern whether this abandoned world offers us a glimpse into the future doom of Earth.
Venus is so similar to Earth, but so, so different.
NASA/JAXA/ISAS/DARTS/Damia Buick/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,” Michael Way, a researcher at the Goddard Institute for Space Studies, said in a statement of NASA. “These results show that ancient Venus may have been a very different place than it is today.”
Although Venus is now thought to be absolutely miserable—with a carbon dioxide-dominated, suffocatingly thick atmosphere and shockingly high temperatures—many experts believe that it formed from Earth-like ingredients when our solar system came together. Venus may have had a thin atmosphere and several bodies of water, and overall appears to be a cosmic twin of our planet.
But due to what is called the “inevitable greenhouse effect” on the planet, things have changed.
Simply put, the greenhouse effect refers to the idea that Venus’ oceans have evaporated over time, dumping water vapor into an atmosphere that has trapped too much heat. All that heat led to more ocean evaporation, which trapped more atmospheric heat… and…
Yes
Could this one day happen to Earth too? Especially given the fact that climate change is being exacerbated by human activities such as burning coal and releasing 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, this is not a good example of what will happen to Earth due to human activity. Life on Earth will disappear due to extreme temperatures long before it reaches even half the carbon dioxide concentrations on Venus!”
But hopefully we won’t even come close to 30% of Venus’ scary levels.
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