> I wonder if you bothered to check who wrote that article,

I don't think the appeal to authority fallacy will fly here. We are all too smart for that.

You arguments should be evaluated for their coherence and, in the end, it really doesn't matter who you are or what you did if you are wrong.

To use your example, it doesn't matter if you are Von Braun himself. If you don't bring enough propellant for your descent engine, you'll still crash on the Moon.