True, I understand that. The problem is that plasma propulsion has been around for quite awhile now, however it is not as powerful as conventional rocketry. If you add fusion power to this, it would be the equivalent of blowing a nuke behind a space craft per "pulse". One of the major draw backs of fusion energy (compared to fission) is that we have very limited means of controlling the release of energy as it tends to (annoyingly so) catalyse itself and cause a wonderful chain-reaction like event. I would like to read the actual report from the scientists and engineers first as there are a few dubious elements in this article.