Lots of people who worked on it must spend lots of nights thinking, Oh God, did I tighten that screw
Ha-ha, so true!... I used to do failure analysis for the Mars rovers starting with MER, most for MSL, but I tried to stay away from M2020. It is so rewarding and unrewarding at the same time... When we solve a problem it's great, you get that satisfaction (like pissing a bit in a black suit - gives you a nice warm feeling when while no one else notices). But when Curiosity was landing and the whole world was watching, you start thinking "Did we really fix the parachute issue? (last moment adjustments were not tested)", "Would the radar work long enough? (metal shards kill it in 1 hour, we needed 6-8 min), "Would the Sky Crane work? (we can't even test as we fly), "Would the wheels break on hard landing? (they bent in test), "Would the rover be healthy after landing? (one of its FPGAs was zapped), and the list goes on and on... Honestly, I could not enjoy the landing.