How NASA's DAVINCI Mission Will Plunge Through Venus's Hellish Atmosphere
by EditorDavid from on (#601FD)
"NASA's DAVINCI mission to Venus is scheduled for launch in 2029," reports Gizmodo, adding that a new paper "details this upcoming journey, a daring mission that could shed new light on the scorching hot planet's mysterious, and potentially habitable, past."Upon its arrival at the second planet from the Sun, the probe will plunge through Venus' atmosphere, ingesting its gases for approximately one hour before landing on the planet's surface, according to the paper published in The Planetary Science Journal. DAVINCI is designed to act as a flying chemistry lab, and it will use its built-in instruments to analyze Venus's atmosphere, temperatures, pressure and wind speed, while taking a few photos of its trip through planetary hell... If it survives the atmospheric entry, the probe will - hopefully - land in the Alpha Regio mountains, which are roughly the size of Texas, according to the researchers behind the new paper. Under ideal conditions, the probe will operate for 17 to 18 minutes once it sticks the landing, but it isn't really required to operate on Venus since all the precious data will have already been collected during its atmospheric plunge. Digital Trends calls Venus "a frontier in planetary science about which very little is known" - then explains why that is.The biggest issue for any potential mission to Venus is the heat, as the surface temperatures can be as high as 900 degrees Fahrenheit (475 degrees Celsius). That's hot enough to melt lead, and it wreaks havoc with electronics... The pressure at the surface is around 95 bars, or nearly 100 times the atmospheric pressure on Earth's surface, so engineering a probe for this kind of environment is kind of like building a submarine... To keep the probe active for as long as possible, it is spherical and covered in a thick titanium shell to withstand the pressure and insulate against the heat. Then there's more insulation inside this shell, made of special materials including astroquartz, a type of fiber made from fused quartz... It's then filled with carbon dioxide gas to protect the high-voltage electronics from sparking and to stop any Earth gases from leaking in during launch.... The descent sphere will also have a camera that will be snapping high-contrast images of the surface, which can then be built up into 3D maps. For a camera to operate from inside a metal sphere, though, you need a window. And glass isn't a great material for dealing with intensely high-pressure environments. That's why DAVINCI's window will be made not of glass but sapphire... "Our final images will have 10-centimeter resolution," said the team's principal investigator, Jim Garvin. "That's the scale you'd see looking out across your living room...." Researchers know that the clouds of Venus have drops of sulfuric acid in them - and sulfuric acid eats through materials. It's a particular concern for the Kevlar lanyard that will attach the descent sphere to the parachute. So to test whether the lanyard can withstand the acidic environment, the engineers don't just suspend it in a few drops of acid - they coat the entire surface in acid, then test the lanyard's pull strength to make sure it can survive long enough to take the probe through the atmosphere even in the worst possible case. SciTechDaily notes DAVINCI "is the first mission to study Venus using both spacecraft flybys and a descent probe.... "It will also provide the first descent imaging of the mountainous highlands of Venus while mapping their rock composition and surface relief at scales not possible from orbit."
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