I agree that he peaked later on but the work he did for US Steel as a 28 year old is iconic and amazing as well - the guy was a talent from very early on:
http://www.gavinrothery.com/my-blog/2012/8/6/syd-mead-us-ste...
http://www.gavinrothery.com/my-blog/2012/8/6/syd-mead-us-ste...