Ok then I suggest you look into "light gas guns". Perhaps that is what you seek? Sorry I'm an engineer I can only go just so hypothetical before I see some proof. Perhaps I did misunderstand that is entirely possible. The only other method I can think of that makes sense to me is project Pluto where a nuclear reactor heats the air for propulsion. I believe if just compressed air in a tank could provide propulsion for a rocket we would have done that long ago :) Air breathing rockets are based on high pressure air and there are some hybrids that use both Air and chemical propulsion. Monroe > -------- Original Message -------- > Subject: [AR] Re: Way OT question: degerate matter thrusters? > From: "Galejs, Robert - 1007 - MITLL" <galejs@xxxxxxxxxx> > Date: Wed, February 18, 2015 1:30 pm > To: "arocket@xxxxxxxxxxxxx" <arocket@xxxxxxxxxxxxx> > > > I believe that that's a bad example. If I understand things properly, I > believe that the ISP of the air alone is higher, but the mass flow with water > is much better. > > But you missed my point entirely... I wasn't trying to optimize anything, I > was just trying to see if using hyper-compressed air at some arbitrarily high > pressure could be used to get something into orbit theoretically, ignoring > obvious engineering issues like tank weight. > > - Robert > > -----Original Message----- > From: arocket-bounce@xxxxxxxxxxxxx [mailto:arocket-bounce@xxxxxxxxxxxxx] On > Behalf Of Monroe L. King Jr. > Sent: Wednesday, February 18, 2015 3:20 PM > To: arocket@xxxxxxxxxxxxx > Subject: [AR] Re: Way OT question: degerate matter thrusters? > > Here's a simple experiment to show you. Go down to the toy store and buy > yourself one of the old pump up water rockets. Pump it up with air and let > her > rip. Then fill it with water and try again at the same pressure. > > Monroe > > > -------- Original Message -------- > > Subject: [AR] Re: Way OT question: degerate matter thrusters? > > From: "Galejs, Robert - 1007 - MITLL" <galejs@xxxxxxxxxx> > > Date: Wed, February 18, 2015 1:10 pm > > To: "arocket@xxxxxxxxxxxxx" <arocket@xxxxxxxxxxxxx> > > > > > > So why is supercritical steam "better" than air? > > > > -----Original Message----- > > From: arocket-bounce@xxxxxxxxxxxxx > > [mailto:arocket-bounce@xxxxxxxxxxxxx] On Behalf Of Monroe L. King Jr. > > Sent: Wednesday, February 18, 2015 3:01 PM > > To: arocket@xxxxxxxxxxxxx > > Subject: [AR] Re: Way OT question: degerate matter thrusters? > > > > Well so does HP air. Unless your using just a plain ol jet engine like > > a ramjet. That would be HP air also. > > > > > -------- Original Message -------- > > > Subject: [AR] Re: Way OT question: degerate matter thrusters? > > > From: "Galejs, Robert - 1007 - MITLL" <galejs@xxxxxxxxxx> > > > Date: Wed, February 18, 2015 12:55 pm > > > To: "arocket@xxxxxxxxxxxxx" <arocket@xxxxxxxxxxxxx> > > > > > > > > > Supercritical steam does not require heavy tankage? > > > > > > -----Original Message----- > > > From: arocket-bounce@xxxxxxxxxxxxx > > > [mailto:arocket-bounce@xxxxxxxxxxxxx] On Behalf Of Monroe L. King Jr. > > > Sent: Wednesday, February 18, 2015 2:47 PM > > > To: arocket@xxxxxxxxxxxxx > > > Subject: [AR] Re: Way OT question: degerate matter thrusters? > > > > > > I think Supercritical steam would be better than air. High > > > pressures require heavy tankage. > > > > > > Monroe > > > > > > > -------- Original Message -------- > > > > Subject: [AR] Way OT question: degerate matter thrusters? > > > > From: "Galejs, Robert - 1007 - MITLL" <galejs@xxxxxxxxxx> > > > > Date: Wed, February 18, 2015 12:35 pm > > > > To: "arocket@xxxxxxxxxxxxx" <arocket@xxxxxxxxxxxxx> > > > > > > > > > > > > I know this is way off-topic, but it has always had me wondering > > > > and it seems like Arocket has the appropriate knowledge base to > > > > address this (or, at least wildly speculate). > > > > > > > > > > > > > > > > In some of Larry Niven's sci-fi stories, he imagines rocket > > > > thrusters (between the ground and orbit) based on super-compressed > > > > air (supposedly "nearly degenerate matter"). Would such thrusters > > > > theoretically work, or are there some thermodynamic (or other > > > > physics) limitations that come into play? > > > > > > > > > > > > > > > > Thanks, > > > > > > > > > > > > > > > > Robert