I've seen a picture of magnetic jelly that bends, contracts, etc. when an electrical current is put through it. The Spartan suit is TOTALLY possible, and if mankind got together and tried hard enough I don't think we need 500 years, but of course things are complicated... so it just might have to happen later... 400-500 years later.
Every time I look at the 7th image of the reference picture collection above us, I can imagine and almost see it's possible construction and system but I only know so little so it basically comes down to my day dreaming
Still, imagine being able to jump your height, take multiple rounds of high speed projectiles, run for virtually forever, and Promethian Vision. aaaarrgghghg