tht would be the most awesome thing ever..but i dont think at the moment it's possible. if we try to make one right now, then it would be hell and cost billions of dollars and would probably be too slow for warfare. However, if we truly start investing in it now, but plan for it to be released some where for the WAY future, i think we can do it.
one other factor u must think about is: wht would it be used for? War fare? Giganto toy? Loading incredibly large items? so many things to consider..