I wonder if STOIC is still an expansion-deflection nozzle? I assume so.
I seem to recall it being said that the addition of Expansion/Deflection nozzles to SABRE engines means that the required distance to reach takeoff speed, and so the maximum length of the runway allowing abort capability will be reduced to less than the max length of 5,500mtrs, which to my mind has always been a problem. Not a project-stopping problem but a significant PITA.Would anyone care to speculate, if we take it as read that Expansion/Deflection nozzles are used, what the standard takeoff/max runway length would be?
The SABRE engine requires a novel design of the rocket engine’s thrust chamber and nozzle to allow operation in both air-breathing and rocket modes, as well as a smooth transition between the two. The Advanced Nozzle project is demonstrating the feasibility of this concept and represents a significant technology development effort towards the SABRE demonstrator engine.
Will the test engine have a name? "SABRE demonstrator engine" seems a bit unwieldy, or is it so close to a flight model SABRE it's more like SABRE v0.9?
I suppose there is also the thought that Skylon doesn't have any kind of thrust vectoring and I'm not sure how much that affects the usefulness of a ramp.
I thought it was just the chambers/bells that were supposed to gimbal. And not by much; this isn't a Harrier here...
@t43562I think you'll find that Skylon's takeoff speed is around Mach 0.5. I'm not an engineer but I really wouldn't want to hit even a very modest ski jump at anything like that speed...
Given Reaction Engine's approach of having as few unconventional technologies as possible, I suspect launch ramps are something that may not be considered for the first wave.
The real killer for this idea is that a large proportion of the runway is for abort contingency, where Skylon cuts off the engines and slams on the (water cooled) brakes.Bang (crash, bang, wallop) goes the intact abort option when you fall off the end of the ramp while braking...
My very dodgy guess at Skylon's T/w is 0.26.