NASA have just published a NASAfacts sheet for the Green Propellant Infusion Mission Project. Probably doesn't offer much new, but I did notice the following:"The Green Propellant Infusion Mission is scheduled to launch aboard a SpaceX Falcon Heavy rocket in late 2015."http://www.nasa.gov/sites/default/files/files/Green-Propellant-Infusion-Mission-Project_-Fact-Sheet.pdf
I am curious if it's possible to modify older thruster designs to use this safer and higher energy density propellant? Let's say SpaceX's Draco/Super Draco. Also, would this propellant be well suited to a propellant depot architecture?
By way of comparison:http://www.eads.com/eads/int/en/news/press.20130618_astrium_ecaps_green_propulsion.html"Astrium and ECAPS develops a new ‘green’ propulsion system"18 June 2013The Europeans seem to like ADN (Ammonium Dinitramide). ATK tested that propellant in the U.S. How did GRC decide to go with HAN?And then: are both of these sort of like NOFBx, i.e. are they blends of fuel and oxidizer that somehow stay safe and usable even when mixed together?
I'm not a satellite guy, but I don't think propellant is usually the life-limiting factor.
Quote from: strangequark on 07/12/2013 09:27 pmI'm not a satellite guy, but I don't think propellant is usually the life-limiting factor.For a conventional GEO sat, most of its propellant is used in the GTO -> GEO circularization burn, and the attitude control slowly works through the remainder. So, if you're going to replace hydrazine, you really need to be able to do both.
I guess most people is interested in the RCS role. Of course that for the GTO it would need to be able to do the kick (about 400N thrust). Unless the set is SEP in which place there's no point on using this.One part that I find interesting is about processing facilities and cost. Could it be fueled on current facilities? Could new facilities significantly lower the processing cost vis-a-vis an hypergolic?It would seem, though, that the best candidate for this would be human rated systems. Specially returning ones.
Anybody know the density of the propellant being used? Wikipedia says it's "extremely dense" but doesn't give a number...