Designing & Building Martian Rovers to Transport EVERYTHING! | Mars First Logistics 

Or even better setup, with way more convenient handling: make it not "x"-like, but rather "+" like, install 8 jets: 2 on each arm. Bind controls as follow: . . . . S . . . . . . . . * . . . . D * . . . . * A . . . . * . . . . . . . . W . . . (where * is any suitable key, space, shift or ctrl, or even random "h") note, wsad is inverted! This way by pressing "*" the craft will start propelling, and by pressing WSAD it will tilt forward, backward, leftward, rightward respectively. To turn, say right, it'll be sequence of tilting D-S-AW (latter is leveling the craft after two-axis tilting). Aslo easy strafing in any direction, staying afloat by mashing * at certain rate, and cool look as a bonus). Surely x-shape would be more effective, but i doubt you can effectively operate it _manualy_ by balancing between mashing four buttons at different rates)

bottom should be long enough rotation-type claws (like ones you've used to fix the ball from bottom and top, but quite a bit larger), to be able to grab literally anything. These will also serve as landing pads.