Re: Shameful
The AGC was a cool bit of kit, and probably could have landed the LEM by itself, on a good day and with flat terrain. As it was, every single lunar landing was hand piloted.
What the AGC couldn't do, was land accurately enough to hit (for example) a 50x100m barge in the middle of an ocean.
The other advantage the LEM had was that the descent engine could be throttled a lot (most rocket engines can only throttle between 80-100% of max thrust), all the way down to 10% thrust. The Space X Merlin, while it can throttle down to 70% , that's still a thrust to weight ration of more than 1, ie, it's incapable of hovering. This means that to land, not only does it have to deal with all the problems of being pretty much the wrong shape to land (like balancing a pole vertically), an inconsistent atmosphere with wind to push it around, much smaller landing areas, it also has to time it's 'suicide burn' so that the rate of de-acceleration is perfectly calculated to have it moving at 0m/s exactly at altitude = 0m.
If it is still going too fast it crashes (obviously), but if it's going too slow then it will start going back upwards (and would presumably have to then cut engines and try again somehow).
Finally it has to do all of this whilst being cost-effective enough that they can make money by re-flying that stage again and again.
So yes, the LEM and the AGC were massive triumphs, but modern rocketry has come on leaps and bounds, and while automated landings might look the same from the outside, the level of difficulty is an order of magnitude higher.
Biting the hand that feeds IT
