One big technical challenge to solve if we ever want to live on Mars is how to make fuel. Sure, you can ship it from earth, but every pound of fuel requires 225 pound of fuel to deliver it - so that's not at all efficient.
But it turns out that Martian dirt can be turned into rocket fuel, which led to a different question: how do you dig in the low gravity of Mars?
Enter the space digger called RASSOR or Regolith Advanced Surface Systems Operations Robot.
Kurt W. Leucht wrote an article over at IEEE Spectrum to explain it all:
To dig, RASSOR uses two opposing bucket drums, each outfitted with several small and toothy digging scoops. When RASSOR’s bucket drums spin and the arms that hold them dip down, they scrape up just a small amount of regolith into each digging scoop as it drives slowly forward. This creates a shallow slot trench rather than a deep hole. These rotating and digging bucket drums are hollow inside, allowing them to collect and hold the excavated regolith. Another key feature of RASSOR is that, while digging, the bucket drums actually spin in opposite directions. This cancels out much of the digging forces and will allow RASSOR to excavate in low gravity.
See it in action in this video clip below: