Within the next decade, NASA’s DAVINCI mission plans to send a descent sphere whistling through Venus’s atmosphere, collecting not only samples of its atmosphere but also high-resolution images of the planet’s surface. But Venus is a profoundly inhospitable place, with surface temperatures hotter than an oven and pressure so great it’s like being 3,000 feet under water. Now, NASA has shared more details about one of the DAVINCI mission instruments and how it will collect vital data in this very challenging environment.
DAVINCI’s VASI (Venus Atmospheric Structure Investigation) instrument will be responsible for taking readings of the atmosphere as the descent sphere falls through the atmosphere on its 63-minute fall to the surface, including data collection. about temperature, pressure, wind speed and direction. . This should help answer some long-standing questions about the planet’s atmosphere, particularly its lower atmosphere, which remains a mystery in many ways.
“There are actually some big puzzles about the deep atmosphere of Venus,” VASI instrument lead scientist Ralph Lorenz of the Johns Hopkins Applied Physics Laboratory said in a statement. “We don’t have all the pieces to that puzzle and DAVINCI will give us those pieces by measuring composition along with pressure and temperature as we get closer to the surface.”
The researchers want to know how the surface interacts with the atmosphere and whether volcanoes observed on Venus interacted with the atmosphere in the past. We know that there are many of these volcanoes on Venus, but we don’t know if they are active today or not. Understanding the history of volcanism is particularly important to understanding whether the planet could ever have been habitable.
“The long-term habitability of our planet, as we understand it, is based on the coupling of the interior and the atmosphere,” Lorenz said. “The long-term abundance of carbon dioxide in our atmosphere, which we really rely on to keep the Earth’s surface warm enough to be habitable through geologic time, depends on volcanoes.”
It’s no easy task to design something that can withstand not only the high temperatures and pressures of Venus, but also the corrosive sulfuric acid found in its atmosphere. VASI will collect data using a temperature sensor that is encased in a metal tube like a straw to protect it from the atmosphere, and its atmospheric sensor uses a silicone membrane stretched over a vacuum to detect distortions caused by pressure. Other sensors in VASI include accelerometers and gyroscopes used to measure wind that will be held securely within the thick descending titanium sphere.
“Venus is difficult. The conditions, especially low in the atmosphere, make it very difficult to design the instrumentation and the systems to support the instrumentation,” Lorenz said. “All of that has to be protected from the environment or built in some way to tolerate it.”