Hello All,
Tonight/this morning I watched the YouTube video of Rocket Lab's latest satellite launch (aboard their Electron vehicle:
http://www.youtube.com/watch?time_c...2&v=idKCy8LdyKo ), which occurred on Saturday. Although I was aware of their rocket's new kick stage, whose rocket engine is named Curie (see:
http://www.google.com/search?source...i67.VDmLwn7-ZQs ), I had never thought of its other possibilities until now, and:
The Curie engine, which is 3D printed, produces a thrust of just 120 N (27 lbf), with an unspecified specific impulse, burning an as-yet-undisclosed "green" monopropellant that is pressure-fed to the engine. There are some speculations--informed by a patent that Rocket Lab obtained (its link is on the below-linked webpage)--about what this "mystery propellant" is, though (see:
https://space.stackexchange.com/que...ayload-kickstag ). It is thought to be some kind of liquid (or perhaps even gel-consistency) organic nitrate. (The British Jetex [and later, Jet-X] motors' solid fuel pellets were guanidinium nitrate [more commonly--and incorrectly--called guanidine nitrate], which decomposed, giving off much heat and some smoke when ignited by burning Jetex/Jet-X wick.) Now:
Since the pressure-fed Curie rocket engine produces relatively little thrust when burning its "green" monopropellant (which has a low specific impulse), this type of propellant and engine could be ideal for liquid propellant model rockets. At last, just as the R/C jet modelers eventually got real gas turbine jet engines to power their scale models, we could build liquid propellant flying scale models of liquid propellant guided missiles, ballistic missiles, satellite launch vehicles, and sounding rockets. Even smaller rocket engines (smaller than the 27 lb thrust Curie) would be perfect for scale (and non-scale) liquid propellant model rockets that used the same--or a similar--"green" pressure-fed monopropellant, and lower tank pressure (produced using a hand pump) would also suit such models well. Like the old Cold Propellant (and Coldpower Convertible) model rockets, these monopropellant ones could lift off slowly, and be really perking along at burnout, increasing the scale realism.