Jim, if you're interested in rocketry,
Quote from: R7 on 03/07/2013 12:37 pm... wasn't recently test-fired Blue Origin's BE-3 hydrolox thrust chamber pressurefed?their chamber pressure is between 30 and 100b, which precludes pressure-feeding hydrogen in a rocket.Both the vessel and the remaining gaseous hydrogen are too heavy to make efficient hydrogen stages if pressure-fed.
... wasn't recently test-fired Blue Origin's BE-3 hydrolox thrust chamber pressurefed?
I think you'll find most satellites that use hypergolic AKM's do so because their station keeping thrusters are also hypergolic. So if you want to introduce LO2/LH2 to comm sats you'll need to replace hypergolics for both uses.