If I understand the article, that would require either a new both radically strong and radically lightweight material for the non-propellant parts the rocket (a

If I understand the article, that would require either a new both radically strong and radically lightweight material for the non-propellant parts the rocket (assuming H/O propellant), or using non-chemical physics for propellant that exceeds the payment energy of H/O, and that is stable enough to be relatively safe. Or both.