NASA’s ‘Hedgehog’ robots will hop and tumble through space

These rovers are cubes that can tumble across comets.


Selena Larson


Published Sep 8, 2015   Updated May 28, 2021, 12:38 am CDT

Rovers like Curiosity can roll around on planets, collect data and teach us about the worlds that surround us. But those rovers can’t operate on celestial bodies such as comets or asteroids because gravity is too low, and the rough terrain makes it impossible for rovers to navigate. 

That’s why scientists at NASA’s Jet Propulsion Laboratory, Stanford University, and the Massachusetts Institute of Technology have created cube robots that can hop, tumble, flip, and spin across the low-gravity, rocky terrain to explore the hazardous surfaces. 

Called Hedgehogs, the cubes contain spikes that help guide them over the dusty surfaces. Inside, three spinning flywheels control the robots’ motions and brakes are applied at different speeds to make the robot hop, tumble, or turn in a different direction. 

“The spikes could also house instruments such as thermal probes to take the temperature of the surface as the robot tumbles,” Issa Nesnas, leader of the JPL team, said in a statement. 

Hedgehog can turn in place and hop long distances across rocky and dusty surfaces using a couple spikes, or roll from one face to another to travel short distances. Scientists are working on making the Hedgehogs autonomous, giving them the ability to think for themselves and make decisions on where to travel next without instructions from Earth. The robots would also communicate with a mothership that could track their movements. 

The tumbling robots aren’t ready for space exploration quite yet. But scientists tested two Hedgehog prototypes in a zero-gravity environment and demonstrated they would be ready to operate on a comet or asteroid.

One of the challenges rovers would face on something like a comet would be the potential to fall into holes in the terrain, and not be able to roll itself out. Hedgehogs won’t have that problem—they have an escape maneuver that lets them spin quickly and vertically launch itself out of a sandpit. 


Eventually, multiple Hedgehogs could be deployed on comets and asteroids, and according to NASA, the mothership could place them at different locations to collect data simultaneously. And perhaps the next major discovery could be made my a Hedgehog hopping across a never-before-seen asteroid. 

Photo via NASA 

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*First Published: Sep 8, 2015, 2:35 pm CDT