VENUS FEELERS
Winner of NASA’s “Exploring Hell: Avoiding Obstacles on a Clockwork Rover” challenge.
July 2020
Sponsors: NASA Tournament Lab / NASA JPL / HeroX
As part of NASA’s “Exploring Hell” challenge, the design was selected as the 1st place winner from 572 entries from over 80 countries. The competition launched by NASA’s JPL through HeroX, challenged designers, innovators and inventors to design a mechanical obstacle avoidance sensor for a future Venus rover. The sensor had to be designed to withstand the extreme environment of Venus; the furnace-like heat and the crushing atmospheric pressure, while performing its role effectively in detecting a range of obstacles that might threaten the rover in its long lasting journey.
YouTube link of the design:
https://youtu.be/lHNq7KklkB4
https://youtu.be/lHNq7KklkB4
NASA’s official link to the announcement:
https://www.nasa.gov/…/nasas-venus-rover-challenge-winners-…
https://www.nasa.gov/…/nasas-venus-rover-challenge-winners-…
HeroX link for more info about the challenge and the other winners:
https://www.herox.com/VenusRover/128-meet-the-winners
https://www.herox.com/VenusRover/128-meet-the-winners
Background:
Imagine a world hot enough to turn lead into a puddle, where the atmospheric pressure can crush a nuclear-powered submarine. Now imagine sending a rover to explore that world.
Venus, ancient sister of Earth with a planetary environment just this side of hellish, has been visited by a handful of probes since the early days of space flight. Of the many missions to our celestial neighbor, only about a dozen have made contact with the surface of the planet. The longest-lived landers only managed to function for a couple of hours before succumbing to the relentlessly oppressive heat and pressure.
Despite the punishing conditions, previous missions to Venus have nevertheless delivered important information, such as:
Surface temperature: in excess of 450°C
Surface pressure: 92 times that of Earth
Wind speeds: 0.3 – 1.3 meters per second
Due to the extreme pressure, this low wind speed feels almost like gale-force winds here on Earth NASA’s Jet Propulsion Laboratory (JPL), under a grant from the NASA Innovative Advanced Concepts (NIAC) program, is studying a mission concept to return to the surface of Venus, known as the Automaton Rover for Extreme Environments (AREE), something not accomplished since the Soviet Vega 2 landed in 1985.
Current, state-of-the-art, military-grade electronics fail at approximately 125°C, so mission scientists at JPL have taken their design cues from a different source: automatons and clockwork operations. Powered by wind, the AREE mission concept is intended to spend months, not minutes, exploring the landscape of our sister world. Built of advanced alloys, AREE will be able to collect valuable long-term longitudinal scientific data utilizing both indirect and direct sensors.
As the rover explores the surface of Venus, collecting and relaying data to an orbiter overhead, it must also detect obstacles in its path like rocks, crevices, and steep terrain. To assist AREE on its groundbreaking mission concept, JPL needed an equally groundbreaking obstacle avoidance sensor, one that does not rely on vulnerable electronic systems. For that reason, JPL turned to the global community of innovators and inventors to design this novel avoidance sensor for AREE.
This sensor would be the primary mechanism by which the potential rover would detect and navigates through dangerous situations during its operational life. By sensing obstacles such as rocks, crevices, and inclines, the rover would then navigate around the obstruction, enabling the rover to continue to explore the surface of Venus and collect more observational data.
JPL has issued this Challenge to the global community because the rover must have the ability to successfully navigate in such a demanding environment in order to qualify for additional developmental funding. While the mission to the surface of Venus may be years off, the development of a suitably robust rover sensor will strengthen the case for returning to Venus with a rover, something that has never been attempted before.
How does it work?
The sensor is designed to detect cliffs and holes deeper than 35cm, rocks higher than 35cm, slopes steeper than 30º in any direction and combinations of these circumstances that would cause the rover to tilt exceeding a 30º angle limitation. All this while limited to strict dimensions, mass and, of course, materials.
The design breaks down the solution into three separate systems:
1- Holes detection system.
2- Rocks detection system.
3- Slopes detection system.
The 3 systems work independently of each other but they all actuate one main lever that presses a stop/reverse pin at the center of the rover whenever a threat is detected, triggering the rover to back off and change path..
The holes detection system depends on sets of tri-star wheels (fidget spinners like wheels) connected to the rover by hinged arms. In every set, two wheels are always in contact with the ground, reacting with the typology and scanning the terrain. When a fairly large obstacle is encountered, the whole set rolls and climbs over it then rests on two wheels again. When a set of wheels falls in a recess deeper than 35cm it extends the connected arms drawing Bowden cables with enough displacement to actuate the stop lever.
The rocks detection system consist of a bumper structure that presses against the main lever and trigger stop/reverse pin when it hits an obstacle more than 35 cm high.
The slopes detection system works by means of mechanical inclinometers; two tilt detection devices, one for pitch (forward-backward slopes) and the other for roll (side slopes). In each device a bob weight tracks the direction of gravity, once the inclination reaches 30º (+ve or –ve) it releases the energy stored in a compression spring and actuate a Bowden cable connected to the stop/reverse pin.
