[dylan604]

>There's no justification for designing something one bit "better" than the requirements dictate.

Are the Martian rovers outliers to this rule?

>I want to go up in a ship that's a little better than the absolute minimum.

This makes me think of the "this was built by the lowest bidding contractor" quote

[dclowd9901]

The rovers likely are completely on spec but simply because of all of their redundancies and tolerances designed as they are, they exceeded on-paper minimum expectations.

[beckingz]

The specs were decreased so that "success" was extremely likely, because failure is career ending.

[dylan604]

at this point though, if I was on a team that made a $newShinyToy for a space mission that did not "over perform" like this, I would personally feel shame and have a sense of failure if it only performed to the papers and end of mission came exactly when the paper said.

[tonyarkles]

I wouldn’t go quite that far. Generally speaking aerospace margins are there for two reasons:

- To try to compensate for the worst-case situations

- To try to compensate for the unknown-unknowns

If you made a Mars rover that experienced a worst-case re-entry burn, got blown off-course during landing by larger-than-ever-measured surface winds, had your solar panel etched by dust in said surface winds, and completed 89 of the 90 day mission, you should still very much feel like you’ve succeeded AND you’ve provided incredibly valuable input data for the next iteration. We then refine our mental model of the Martian atmospheric conditions and revise the worst-case scenario specs for next time.