It's a combination of things. Many (most?) of the people want to be there and are passionate about what they're doing. Financially it's still a great job by n

It's a combination of things. Many (most?) of the people want to be there and are passionate about what they're doing. Financially it's still a great job by normal standards and once you have tenure (I think they may call it something else) it's an extremely secure job. I have a friend who works there - brilliant guy who went to school for physics but is also very talented at low level embedded systems type development. When he graduated with a physics masters he turned down a six figure offer to start at NASA at around $60k. From what he's told me though, he's essentially guaranteed to hit the six figure mark within 6-8 years. Last time we spoke he had just started his PhD (paid by NASA) and was working on the Mars 2020 rover.