5 mins read 31 Jul 2020

Brisbane Engineer Takes on NASA Venus Rover Challenge

Callum Heron from Brisbane has taken out third place in the NASA-run ‘Exploring Hell’ competition, which required teams from around the world to design a rover that could land and operate on the harsh Venusian surface.

A collage of the 15 finalists in the ‘Exploring Hell’ competition with NASA. Credit: NASA/HeroX.

What does it take to withstand the intense conditions on Venus? Competing teams from all over the globe contemplated this issue for a recent NASA challenge to design a mechanical obstacle-avoidance sensor to be part of a new Venus Rover, with an engineer from Brisbane taking out third place.

Spacecraft have proven notoriously difficult to run on the surface of Venus due to its extreme environmental conditions. Previously, the longest that any spacecraft has survived on the surface was roughly two hours, achieved by the Soviet Union’s Venera 13 probe in 1981. However, NASA’s Jet Propulsion Laboratory (JPL) is hoping to land a rover on Venus with a potential lifetime of months.

Battling Extreme Conditions

An image of Venus from NASA’s Mariner 10 spacecraft. Credit: NASA/JPL-Caltech.

The planet Venus has long captured society’s imagination. Dr. Alice Gorman, Associate Prof. at Flinders University and Space Heritage Archaeologist elaborated, “Before the Mariner 2 mission in 1962, it was thought that Venus might be a lush tropical waterworld teaming with life. The dense clouds hid the surface from view and allowed terrestrial imaginations to run wild.” 

Dr. Gorman went on further to comment, “Venus has always been my favourite planet. Even as a child I looked for it at dawn and dusk, and I was intrigued by the Babylonian astronomers who recorded its movements  more than 3000 years ago.”

Despite Venus being similar in size and structure to Earth, it is the hottest planet in our solar system. This is due to its thick atmosphere which traps heat in a runaway and uncontrolled greenhouse effect. The temperature on the surface of Venus, a scorching 462-degrees Celcsius, is considered hot enough to melt lead - and as such presents some issues when it comes to designing rovers and machinery to explore Venus. 

Dr. Helen Maynard-Casey, a Planetary scientist from ANSTO who specialises in off-Earth mineralogy, commented on the elusive planet. “Venus is our closest neighbour but is still a total enigma, and for me that makes it really interesting.  It is a terrestrial (rocky) planet with an atmosphere so thick it could actually be a supercritical fluid at the surface.  The surface is peppered by volcanoes, but we’re yet to conclusively catch one being active.  And exploring it is really hard - I always think - what is it trying to hide from us?” she said.

Dr. Maynard-Casey said, “you have three things that are a challenge compared to the surface of Earth. Firstly, the heat - average temperature on the surface of Venus is thought to be about 450°C. Though Aluminium (which is a nice light metal to build your rover of) melts at 660°C, there’s many other usual rover components (copper wiring for instance) that will have long since melted by those temperatures.”

“Next is the pressure - the surface of Venus has a surface pressure 90 times more than the Earth’s surface, which is about equivalent to a depth of 900m under the sea.  This means the rover would have to be much stronger than anything that’s been built before.”

“Lastly, there’s the chemistry - we don’t know for sure but the atmosphere at the surface of Venus is likely to be supercritical carbon dioxide mixed with sulfuric acid – very, very corrosive and likely to eat through metal very quickly.  Do we know enough about metallurgy to design a coating that can withstand this corrosion?  I’m not sure we do yet!” she said.

In order to survive these extreme conditions,  a new rover from JPL has been designed with a mechanical locomotion approach, using a small wind turbine and a system of springs to generate and store energy, like a wind-up watch. Named AREE (Automation Rover for Extreme Environments), this design allows sensitive electronics and delicate computers to be replaced with components made from advanced heat-resistant alloys and limited-capability high-temperature electronics, thereby extending the life of the rover. 

Exploring Hell

Callum Heron’s annotated obstacle-avoidance system design for the Venus rover. Credit: NASA/HeroX/Callum Heron.

To complement this new rover, JPL put out a world-wide call for concept designs for an obstacle-avoidance sensor that could be incorporated into the rover. The competition, called ‘Exploring Hell: Avoiding Obstacles on a Clockwork Rover’ was open to designers, the maker community, and citizen scientists, with prizes as much as $15,000, and was executed on the crowdsourcing platform, HeroX. There were a total of 572 entries submitted from 82 countries.

Senior mechatronics engineer at JPL, Jonathan Sauder, said, “The response from the community was incredible and better than I ever dreamed.”

Engineer Callum Heron from Brisbane, who works on designs for both the space and medical sectors, took out third place in the NASA competition, with his design ‘Direction Biased Obstacle Sensor (DBOS)’. 

On his HeroX profile, Callum states that he is inspired in his engineering design by “The feeling of finding an elegant, constructive solution to a complex problem.”

His design is one of 15 that were chosen finalists for this competition. Beyond the ‘Exploring Hell’ competition, the finalists are also being considered for inclusion in AREE’s design as the rover continues to be developed. 

Learn more about the Venus Rover competition