Ryan Gibbons
This is cool, SpaceX should incorporate this areospike tech in there rockets.
Ryan, While it is possible this idea is not patented I wouldn't bet on it. SpaceX could do something similar or license this tech, possibly even if it is patented.
Mel Tisdale
There has to be a limit regarding the number of small satellites that we can put into orbit if we are going to guarantee that they will not collide with each other and in doing so, increase the danger to all satellites. As it is, the poles are extremely congested.
I have never got around the question, "How is fire pressing against air going too provide the containment too accelerate the reaction mass to the rear enough to matter?" It looks to me like putting a muzzle brake on a rocket. I think putting a thrust augmenter around the whole engine grouping would do more good.
Bob Stuart
I eventually stopped visualizing a horizontal cut in the bell, but I still don't get the "stretch" and "plug" at all. What is the function of the central vent? Do the rockets aim out, and then in? Did an illustration or a paragraph go missing?
@katgod - This version of the aerospike might be. The Aerospike itself has too much prior art to issue a blanket patent that would stick. SpaceX could freely design its own variant and then put it to production so long as their design is clearly not based on the design firefly uses. @Slowburn - This is one of those cases where physics does not follow common sense. Aero spikes have been successfully tested many times. NASA even tested their version that was to go into the space plane successfully accross the intended operational range. It wasn't the aerospike that killed the project, it was the fuel tanks. The new lighter composites could not withstand lift-off vibrations while containing cryogenic fuels. So they were going to have to drop back to heavier aluminum, which reduced the cargo fraction to a point where its viability was in question. Since it was over budget they killed the space plane rather than redesign the entire vehicle.
Firefly and SpaceX are aiming at very different markets. The aerospike engine sounds great at first, but it has been tried and failed many times since the 1960's. It has two major problems: 1) The engine is very heavy, and 2) additional cooling is required for the engine. Both of these come at a cost of "throw-weight" or "throw distance." That is why Firefly is targeting Very Low Earth Orbit, low weight satellites. In the long run, aerospike does not look to be scalable much beyond what Firefly is doing. SpaceX on the other hand is scalable and has several unique features: A) The SpaceX first stages will eventually be reusable. They will return to Earth and a soft landing. B) The second stage is restartable, something that no other production rocket can currently do. This allows efficient missions that can drop off satellites at various orbits and altitudes. C) The SpaceX first stage is seminal technology for future Lunar and Mars manned landers. D) As soon as the Air Force quits impeding it, the SpaceX capsule will be man-rated and able to replace both the Space Shuttle and Soyuz with something bpoth cheaper and more reliable. There are niches for lots of innovation in space.
O.K. then, how about explaining for us dummies out here: "How's a methane rocket going to not add greenhouse gasses to the atmosphere??? I know there's someone out there whose smarter than me!!!
Because if the methane were in the atmosphere, it would be a much more powerful greenhouse gas than the carbon dioxide and water vapor to which it would be oxidized? I guess that would be a net loss of greenhous-ery. (Yes, I know that the methane almost certainly wasn't in the atmosphere to begin with, but you did ask how.)
SpaceX announced in 2012 development of methane/LOX Raptor engine