NASA has never sent a rover to Venus–for good reason. The planet’s surface temperature is so hot, computers, cameras, and sensors can’t function. Since no digital device could survive long enough to gather significant amounts of data on Venus (much less transmit it back to Earth), scientists know little about our neighboring planet.
How do you design an entirely mechanical rover that could survive Venus’s computer-melting conditions? The engineers behind a new Venus rover concept at NASA called the Automation Rover for Extreme Environments, or AREE, looked to an unlikely source: the legendary Dutch artist Theo Jansen.
Now, after AREE was chosen to be developed through NASA’s annual Innovative Advanced Concepts competition, the researchers behind it are in the midst of a two-year feasibility study to see if the rover could really work.
Instead, Jansen shared the designs of a caterpillar Strandbeest he was working on. This new beast’s ability to crawl along a sandy beach inspired the team to implement a track system–similar to how a bulldozer has a track around its wheels to help it traverse different types of terrain. The current concept now has a moving track on all four sides of the boxy design so that if it were to tumble down a cliff, it would still be able to keep moving afterward.
Sauder believes that these types of mechanical computers could be key to building a rover that can survive on Venus and collect data without digital sensors or cameras. He says the prototype will be structured around a clock because it provides a slow release of energy, which makes it a good base around which to build more components. One such component could be a device that tracks temperature over time. The clock could also serve as a timer around which to base different actions–like stopping every 30 minutes to collect a geological sample.
Yet the high temperatures on Venus provide an entirely new set of engineering constraints. Right now, the team is trying to build a clock that will work at 450 degrees Celsius–or about 842 degrees Fahrenheit–which is more difficult than it seems. Materials can completely transform under that amount of heat. Aluminum, a common rover material, becomes “Silly Putty,” Sauder says. Springs, a vital component of mechanical computers, have different yield strengths at high temperatures. Materials expand as they get hotter. Even grease–which is used for lubrication for most mechanical systems on Earth–burns or melts. To test their prototypes, Sauder and his team throw them in an oven. He says their first tries “failed miserably.” But once they have completed the clock, they’ll be able to apply the lessons they learned from it to building the rest of the prototype.
The concept is in the very earliest stages of development–the team has a lot of work to do before getting funding and becoming an official NASA mission. Only one concept coming out of the Innovative Advanced Concepts competition has ever made it to mission status. But Sauder feels confident that the technology they’re developing will be useful to any future mission to Venus, even if AREE doesn’t make it that far.
Studying Venus is important, Sauder explains: It’s very similar to Earth in its size and its distance from the sun, and yet the differences between the two planets are striking–and puzzling. Understanding the difference will have implications in the search for life in other solar systems. Both Earth and Venus fit the bill for the type of potentially life-sustaining planets that scientists look for around other stars, yet only one is hospitable to life. Discovering how they came to be so different could help scientists better identify planets that might host life. “Why is Venus a hellacious planet, where Earth is a great friendly place to live?” he asks.
Only a rover that can survive for longer than two hours on the surface of the planet would be able to help scientists answer that question. Sauder hopes his concept will bring more attention to the planet and inspire scientists to study it. After all, Mars isn’t our only neighboring planet with secrets.
The team working on AREE also includes Evan Hilgemann, Michael Johnson, Aaron Parness, Bernie Bienstock, Jeffery Hall, Jessie Kawata, and Kathryn Stack.