G. Mark’s Answer
You should be aware that NASA is not simply the people who shoot rockets into space or build really fast aeronautical vehicles. NASA is involved in studies in a wide variety of sciences from chemistry to geophysics to advanced engineering methods and climate analysis. NASA represents scientists and other professionals in a similarly diverse set of disciplines. As the premiere space agency -- and a host of other areas of authority -- in the world, they not only work to help the US with related concerns and exploration, but also collaborate with other nations in their own efforts.
It's safe to say that if you decide to work as a scientist in NASA, you will make a difference. Be aware that whenever someone is dismissive of the value of "shooting rockets into space" that NASA not only has a major impact on many areas, not to mention our knowledge of "what's out there", but also has been responsible for the development and advancement of many of the technologies we take for granted that fuel the phenomenal scientific and commercial advancements we enjoy today. In fact, were it not for NASA, you wouldn't be reading this right now. And I wouldn't be able make it available to you at this moment.