Rocket Science for Earthlings 46
a continuing series for the gravitationally impaired
NASA says. NASA says that gas pressurized rocket systems are only for small motors, but the SNORT test track rocket was gas pressurized and big, and the Bomark A produced 35,750 pounds of thrust which is pretty big. The rocket engine tested by Beal Aerospace produced 816,000 pounds of thrust which is really big. Studies have shown that big pressure fed rockets work just fine.
NASA says that due to the requirements for tight tank pressurization specifications and a fear of overshoots and spikes that might burst those thin tanks, a lot of money has to be spent on the pressurization system almost twice what the engine costs to absolutely guarantee the safety of the tank - as part of their manned vehicle rating system.
Of course having painted themselves into a corner they can then justify spending huge amounts of money on turbo pumped engine systems.