NASA Rovers Keep Getting Stuck, And We Finally Know Why

Although humanity is getting better at sending robotic probes out into the Solar System to explore the places no human can tread, we're still very much on a learning curve.

The first extraterrestrial robotic rover was launched from Earth in 1970. It's only now, more than half a century later, that scientists have figured out why these marvels of ingenuity and engineering keep getting stuck in the soils of alien worlds.

"In retrospect, the idea is simple: We need to consider not only the gravitational pull on the rover but also the effect of gravity on the sand to get a better picture of how the rover will perform on the Moon ," explains mechanical engineer Dan Negrut of the University of Wisconsin-Madison.

"Our findings underscore the value of using physics-based simulation to ana