Ever since the first rovers sent to Mars “disappointed” government officials by not accomplishing their goal of finding life.

Nowadays, NASA has to be much more lamesauce conservative about their goals in order to secure and maintain funding by making politicians happy.

Every estimate was probably made as pessimistically as possible so that anything that was better than “exactly according to these pessimistic plans” was a positive surprise, incentivizing politicians to give them further funding to do what they really want, which is really cool stuff. The quiet part they can’t say out loud…