[CertainInalienableRights]

I'd hazard a guess that plenty of "rocket scientists" may have noticed the misspelling. But given that NASA is a government agency, and therefore presumably heavily unionized, any attempt to infringe on the work of the "sign hanging job classification" people would likely be met with more than a bit of backlash.

Just a guess, based on my two experiences in working at heavily-unionized organizations. Its one of the reasons why all my jobs since have been with smaller-sized, privately-held companies.

[cripplecreek]

I would look at it as a recognizable sign even if misspelled thus not worthy of the expense of replacement.