I used to work at Jet Propulsion Laboratory, worked on MSL (the Mars rover mission that's grown to $2.5B), and did some R&D on a system that *could* end up on a Europa mission. The entire Jovian system is a radiation nightmare. If I remember correctly, it'll take years for the spacecraft to get there, we can orbit Jupiter relatively safely, but as soon as we orbit Europa or Ganymede, mission life is like another 45 days? The electronics will simply die of overdoses of radiation. Also, currently no FPGAs, can survive this radiation environment long enough to get any science done. Yes, there are *some* rad-hard FPGAs, but, again, they cannot take the total integrated dose (TID) of radiation that the Jovian environment is going to dish out in a short about of time. This means, the spacecraft would need about 30 ASICs between control avionics and instrument packages. That is no small (nor cheap) undertaking. I don't know what they mean by "cheap" missions. I think of earth orbit sats for like $300M, but you're not going to Jupiter for less than $1B. But even then, I think MSL was originally bid at $0.8B and look what happened. These systems are ridiculously complex and sometimes it's a situation of not knowing what you don't know. When you finally get a glimpse of what's really going on, well costs go up... a lot. Also, NASA doesn't just say, "hey let's go here". It's all about the science and you need scientists that want to study something there. The most recent decadal survey (http://www.universetoday.com/83813/where-to-next-decadal-survey-prioritizes-future-planetary-missions/) showed more scientists interested in Mars and what-not compared to outer planet missions.

If you spend the time, you can pick up almost anything technical on the job and with some studying on your own time. However, still in many companies, to move up into management or into positions that have more decision making power, they like to see an MBA. The thing is, as you get older, you need to move into management. The only technical people that are still doing the "grunt" level work are the ones that are the absolute best at it. Anyone that's >45 and just good or better than average will get pushed out or replaced by someone younger that can do the same job. This is because that older engineer still doing coding or modeling, etc has a huge salary compared to that fresh out. Simply put, fresh outs don't get management jobs.