I think the languages is the least of the necessary requirements to fill that position. You could learn Fortran in a weekend, and assembly you just have to get a head for but it isn’t hard. (How to accurately apply those tools is just experience over time, as many of us know.) What NASA likely needs is efficiency in a lot of different uses of that term, reliability in ways most of us don’t have to worry about, and the ability to work with some serious stress that isn’t so much as your boss yelling at you because he’s a jerk, but your boss yelling at you because your code is failing and it might kill someone and cost millions of dollars and a PR nightmare.
Which do you think is harder & why? Stupid Question?