Altho I love the look on his face, shouldn't he be wearing a streamlined helmet?

Seriously, tho, these things are all about the energy density of the fuel. Peroxide catalyst rockets have been standard for these experiments, and improvements in nozzle design, catalyst chamber and control systems have made only a 50% increase in duration in 50 years. It will take huge breakthrus to make this useful for combatting the Radar Men from the Moon.