E.g. nuclear pulse fission/fusion is literally 1960s tech. See the Orion project (or NERVA). There are other proposals, which haven't gotten much funding. The

E.g. nuclear pulse fission/fusion is literally 1960s tech. See the Orion project (or NERVA). There are other proposals, which haven't gotten much funding. The whole field of propulsion research has been underfunded since the 1970s, probably because NASA didn't want to risk creating competition for their big job program -- the Shuttle...