Yes, it was possible but did not happen. Somebody(s) has to be the person/people that does it. Nuclear powered rocket engines existed in the 1960's, but little to no work has been done on that problem since then. If someone develops one in 2361, proclaiming, "not big deal, we could have done that four hundred years ago" is a bit silly.

Musk went to NASA's website back in 2000 or so looking for the man to Mars plans and found nothing so he started a rocket company to bring down launch costs by a factor of 100. Ten years later reuse of rockets is happening. Amazing isn't it. Let's see what the next twenty bring.