I would argue that we havent forgotten how to do spacecraft or even landers. We have the documentation and plenty of engineers in the workforce that have had su

I would argue that we havent forgotten how to do spacecraft or even landers. We have the documentation and plenty of engineers in the workforce that have had success in landings, its just that its really hard to do these things. And on top of that we are doing this in a totally new way with the rise of the 'New Space' approach.