It's quite simple, it's two concentric shafts, one inside the other. As for steering, I haven't looked at the Mars copter, but helicopters have a device called a swashplate that lets you change the pitch of the blades selectively as the blades spin around 360 degrees. This gets you selective thrust in any direction.
An extreme example of a swashplate would be in 3D helicopter flying.
Re:Does anyone know how it steers? (Score:5, Informative)
It's quite simple, it's two concentric shafts, one inside the other. As for steering, I haven't looked at the Mars copter, but helicopters have a device called a swashplate that lets you change the pitch of the blades selectively as the blades spin around 360 degrees. This gets you selective thrust in any direction.
An extreme example of a swashplate would be in 3D helicopter flying.
https://www.youtube.com/watch?...
This is where the swashplate has extreme throws compared to a full-size one...
The Kamov Ka-50 is a full size coax helicopter.