Comment by bitL

Frankly, why is it so hard? The article doesn't really show anything outside dust playing role in the very final stage but most landings failed higher above ground. These days we even have lasers to instantly detect distance to the ground that could be incorporated real-time to thruster output. There is almost no atmosphere for friction so basic Newtonian mechanics should be able to make a decent landing. Orbital mechanics is also out of the question near the ground. Why is this still an unsolved problem?