Made the powered landing analytical solution problem yesterday into a simulink model:
A 1000 kg vehicle coming in at 100 m/s decelerates at 20 m/s^2 in 5 seconds and 250 meters. The impulse needed is 130 000 Ns. (The model becomes unrealistic after 5 seconds since the vehicle starts moving up but the drag still points up, but that was no interest to us in this simple model.)
More sophistication can be added: variable mass for better accuracy, and of course more refined landing methods as well as sensor limitations. Stay tuned to the blog!