University designs paper aeroplanes for Mars
The future of Martian exploration may rely on a distant relative among the most mundane items to be found on Earth: cardboard.
A group of engineers has created a tiny aircraft that is powered by light and weighs less than a fly, which they believe could help Nasa explore more of Mars. The aircraft would be made of ‘‘nanocardboard’’ and could be used to help collect samples and discover more of the red planet.
Nasa is just three months away from sending a robotic rover to Mars, in a mission called Perseverance, where the vehicle will seek signs of ancient life and collect rock and soil samples for possible return to Earth.
The rover comes with a drill to get into Martian rocks and soil and conduct geological assessments, as well as determine if the environment could be habitable for humans.
Nasa has designed a small helicopter to join the rover, which will provide a bird’s-eye view of the planet, allowing scientists to survey unexplored territory and plot new routes for the rover.
However, engineers from the University of Pennsylvania’s School of Engineering and Applied Science say they have come up with a more lightweight and cheaper alternative. ‘‘The Mars helicopter is very exciting, but it’s still a single, complicated machine,’’ Igor Bargatin, assistant professor of mechanical engineering, who led the research, said. ‘‘If anything goes wrong, your experiment is over, since there’s no way of fixing it.
We’re proposing an approach that doesn’t put all of your eggs in one basket.’’
Bargatin estimates that Nasa could pack more than 1 million of the tiny craft into a spaceship to equal the mass of the one helicopter, which weighs 1.8kg.
The tiny planes that his team have been working on since 2017 consist of hollow plates of aluminium oxide just a few nanometres thick that weigh less than a thousandth of a gram.
Shaped in the form of strips of cardboard, the planes rise from the ground when a bright light is shone on them. The engineers say this light could be provided by lasers from the Perseverance rover.
As one side of the flat panel aircraft heats up due to the energy of the light, the difference in temperature causes air to circulate through the aircraft’s hollow structure. The air then shoots out of corrugated channels in the aircraft’s sides, thrusting the device into the air.
The laser would also be able to guide the device, since the direction of the air flowing out of their channels depends on which parts of the plate are heated.
The team say that the thinner atmosphere on Mars would give the aircraft a further boost, enabling the planes to carry payloads ten times as heavy as they are, while the weaker gravity on Mars would also help.
The engineers, who have received a grant from Nasa to develop the idea, are now working to see if they can equip the planes with chemical sensors that would be able to detect sources of water or methane – key signs of life on Mars.