40-year-old engineer looking to switch to a new career path. What “new” field should I transition to?

I’ve been an engineer for 15 years, currently in my 40s, and very disappointed in my field. We’ve gone from designing the next generation of stuff to just maintaining what is out there. I’ve been very lucky and am very financially secure. I’m seriously looking to change career paths, mainly because my field isn’t exciting to me anymore. I have many things working against me, 40 years old, looking to start over, and very “fussy” about the field I’m looking to enter, and I’m not sure if I’m ready to go back to school for a full degree. I’ve been stuck in this field for 15 years and I want to get out before I burnout. <br><br>I’m looking for a field that is:<br><br>1. Either still in its infancy or a field that has a lot of “growth” left to it. Example: Solar engineering perhaps, but I’m very “fussy” about this. <br><br>2. The field pays well, I’m currently highly paid, perhaps 200k per year. I want to stay around this number, or close to it. I’m very “fussy” about jobs that pay around 100k or below. <br><br>3. Last 15 to 20 years or more. Example: if I enter a field at 45, I don’t want to see the industry dying on me in 10 years. (I’ll likely retire at 65). <br><br>4. Doesn’t require a full degree. I’m open to more education, but I’m under the belief that a full degree (Even if the school pays for it) is the most difficult path to take. I’m open to certifications but prefer to avoid it as well. <br><br>I’m currently an engineer for a large company in another field. I get to pick and choose the projects I work on and can essentially come and go as I please. My job is absolute cake and I should be excited about my career. The truth is, I’m not! I’m not sure what’s wrong with me, but I’ve been feeling this way for a long time. I’m satisfied with my job, but I’m not happy with my field. <br><br>I’ve done lots of research on “top 10” lists and the like, but “top 10” lists tend to be lists of what has recently been in the media or things that are hot, but also over-hyped. I’ve looked over Chambers, but the problem is that many people here are extremely excited, which is good, but also tends to make things over-hyped. I’m looking for a field or area that is still very young, but not so young that it will be 10 years before things are happening. I’m sure that there will be jobs in space engineering perhaps, but what’s the use of the field if I’m not allowed to get involved until I’m 60. I’m looking for something that is still in its infancy, but also has some things happening, currently in the world. <br><br>I’ve thought about medical device engineering, renewable engineering, software engineering, etc. The problem is that many of these fields are very “mature” and have been around for many years. I’m worried that I’m just jumping into another field that is just as boring as my current one. I’m looking for something that is more dynamic, lots of “growth” and things happening in this area. It’s very hard to find fields or careers that fit what I’m looking for. Example: Solar engineering may be new, but it’s still a relatively “mature” field. I’m looking for something that is new-ish, has exciting things happening, but still has many years before it “matures”. Example: Solar engineering is still young, but “mature” enough that I’m not sure if it’s the field for me. I’m still looking perhaps, but I think I can do better. <br><br>I’m not really sure what to do here. I’m highly paid, my job is easy, but I’m very unsatisfied. I’m extremely “fussy” about the career path I’m looking to enter, which isn’t helping. I want to get involved with this new field ASAP because I don’t have very much time to “play around” (I’m 40). Any recommendations of what field I should get involved in?