It's hard to think of a more hostile environment than the surface of Venus. Temperatures reach 860 degrees, the air pressure is enough to crush you, the clouds are made of sulfuric acid, which deposit rain that, because of the extreme heat, evaporates back into a never ending toxic cloud, and the atmosphere is so thick, it feels like you are moving in gelatin.
Back in 1984, the Soviet Union sent a lander to Venus to explore the surface. It melted in two hours. With all those challenges, how do you launch a mission to Venus that can withstand the conditions and conduct scientific investigation worthy of the effort?
[image-62] [image-78] Testing the components that make up landers and rovers is key. NASA Glenn Research Center has just installed a new Extreme Environments Rig, which can create the high-temperature, high-pressure, toxic conditions found on Venus as well as other extreme environments. It can create atmospheres with accurate mixing down to the parts per billion.
"Any mission you do requires functioning electronics, communications and power," says Rodger Dyson, principal investigator. "Just a few years ago, we didn't have the technology that could survive on the surface very long. We've made advancements in the last three years, but it all needs to be tested."
The Extreme Environments Rig is the largest test chamber of its kind in the country. It can cook anything inside up to 1,000 degrees Fahrenheit and crush it under pressures 100 times that on Earth. The rig can simulate altitude conditions above Venus from the upper atmosphere to the surface. Simulated conditions include all the most corrosive chemicals such as hydrogen fluoride and hydrogen chloride, which can destroy materials used on landers as they approach the planet.
"Many missions have been lost just trying to get down to the surface of Venus," explains Dyson. "But by simulating the conditions in the rig, we can watch the effects and make changes."
The goal is to develop mission-ready components with the ability to last for at least five days and if possible, up to one year. Components include electronics, communications systems, motors, insulation, balloons, sails, radiators, heat pipes, pressure vessels, drills power systems, batteries and cooling systems.
The equipment built from these components will look at a variety of questions. For example, here at Glenn, engineers are designing a seismometer to examine volcanic activity and to see why there are no plate tectonics on Venus. In addition, the rig can test the materials needed to explore remote areas of Earth such as volcanoes and deep ocean locations, which have the challenges of heat and pressure.
And while the Extreme Environments Rig was originally designed to test components, many other uses have evolved. NASA already has customers who want to use the chamber to test simulated Venusian soil, how the speed of sound moves through the atmosphere for weather forecasting and how lasers project light so a lander can see where it is going. "The rig will be used immediately to answer basic science questions since we've only spent a couple of hours on the surface all those years ago," says Dyson. "We will be looking at the basic properties of the planet and how our diagnostic tools work to understand the physics and chemistry of Venus."
According to Dyson, if you can develop technologies that can survive on Venus, you can explore anywhere else in the solar system with the exception of Jupiter, which has the added challenge of radiation. "One of the coolest things about our rig is what it can be used for outside our solar system," explains Dyson. "People have been looking at these extrasolar planets (exoplanets) which are 20 light years away and would take 100 years to reach with probes. The only way to answer some of the questions about these planets, besides using telescopes, is with our rig. We know how to set up the rig by making calculations about their atmospheres and some of them are approximately the same size and temperature as Earth."
One of the ultimate goals of the exploration of Venus is to determine why this planet, which was thought to have had the same temperatures and water as Earth, went hot and toxic. The Extreme Environments Rig is poised to help prepare missions that will eventually answer those mysteries.
For more information:
Nancy Smith Kilkenny, SGT Inc.
NASA’s Glenn Research Center