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:: ALBUM :: DOWNLOAD :: The age of RAPIER Clustering is near its end. SABRE Sterling brings power, functionality, efficiency and style that has not yet been seen in KSP concerning SSTOs, and brings your part count under control if you want visually accurate yet "stockalike" SABRE/RAPIER assemblies. This part pack when released will provide two families of parts for building out a SABRE: The "Advent" series (in 2.5m, based on the official thing which is marked for production, with testing expected to begin in 2020). The "Precedent" series (in 3.75m, the early concept, super-sized, curved engine with 4 bells for the Closed Cycle rocket mode. The 3 in "SABR3" comes from here). What the SABR3 can do for you: Offer the engine in both composite form and component forms (separate) for more fluidity of operation of Air-Breathing and Closed Cycle modes. The nacelle and intake will provide a velocity driven function for producing Oxidizer like the real thing will, featured in Thor Tech. Adjust its performance envelopes for effective use in upscaled systems. Currently, only the intercooler adjusts, and will even show it in its part description. Optimized for 2.5x. Aiming for real scale.

This is a stock 1:1 replica of the SABRE hypersonic precooled hybrid air-breathing rocket engine currently being developed by Reaction Engines Limited. This engine is slated for prospective use on a variety of hypersonic aircraft, although most famously for the Skylon launch vehicle. I would suggest throttling down slightly before switching over to rocket mode, this isn’t strictly neccessary but I found that the sudden burst of thrust from the Vectors occasionally caused the engine to explode. This engine is powered by 8 R.A.P.I.E.R.s and 4 KS-25 engines. SABRE Engine Information: Download Link: https://kerbalx.com/Kronus_Aerospace/SABRE-Engine Part Count: 110 Replica Thrust Rocket-Mode Vac: 2940 kN Replica Thrust Jet-Mode SL Mach-1: 1920 kN Replica Gimbal Rocket-Mode: 1.6° Replica Gimbal Jet-Mode: 3° Replica Mass: 38.9 tonnes Real SABRE Thrust Rocket-Mode Vac: 2940 kN Real SABRE Thrust Jet-Mode SL Mach-1: 1960 kN Real SABRE Gimbal Rocket-Mode: Unspecified Real SABRE Gimbal Jet-Mode: Unspecified Real SABRE Mass: Unspecified

There's quite a bit more info to be found on academic papers on the internet than is currently to be found on Reaction Engine's website. The problem is, a lot of it goes over my head To keep things simple, the SABRE engine is like a jet engine, except it uses the supercold hydrogen fuel to chill the incoming air before feeding it to the compressor. This keeps the compressor light and compact and allows it to work to higher mach numbers than conventional jet engines. The combustion chamber and nozzle look a lot more like that of a rocket engine than a jet, but ultimately have the same function. This engine can run a little over mach 5, a significant improvement over the pratt and whitney j-58's "a little bit" over mach 3. What's the limiting factor? Is intake drag reducing net thrust to the point it'd be more efficient to go "closed cycle"? Or is it the old enemy, heat? In conventional jets, the incoming air stream gets compressed in the intake as it gets accelerated to the speed of the aircraft. This happens before it meets the turbine's compressor stage, and since gases get hotter when compressed, there is a temperature limit. You can make the compressor out of the same heat resistant materials as the turbine, but that adds a lot of weight (over aluminium alloys that would otherwise be used). Also , since the air is hotter before fuel gets burned, it will be hotter still after combustion, and you could then run into turbine limits , which are already using the most heat resistant materials available. The only options then are to reduce fuel added in the main combustor and burn more in the afterburner, or lower the engine compression ratio, both of which hurt performance and fuel consumption. An SSTO engine needs high TWR or it's going to add too much dry mass to the orbiter. Would it be correct to say that in the intake, as the air is sped up to the speed of the airplane, kinetic energy is being converted to compression and heat gain in the air. Theoretically, that energy gets returned back to kinetic as the gas flow expands through the turbine stages and back out the nozzle. But in practice there will be losses, which set the limits for air breathing propulsion of any kind. Apparently, at mach 8, the kinetic energy of the intake air is equal to the chemical energy that can be released by burning fuel in it to use up all the available oxygen of that intake air charge. So unless your ram compression/expansion is perfectly efficient, you can see how hard it is even for scramjets to make max thrust. Speaking of Ramjets, the SABRE has "bypass ramjets" surrounding the four combustors/bell nozzles. Apparently, more liquid hydrogen is used needed to cool the incoming air , than the main engine can use. So the excess hydrogen is burned in the bypass ducts. They are sometimes known as "bypass ramjets" but apparently the goal was "negative drag" not thrust. Even so, do they provide more power at higher speeds? I'd be interested to know how the power characteristics of the proposed engine would look. Certainly the Kerbal RAPIER has a mad 8x thrust multiplier at high speed. The only info i could find on the SABRE, stated that the core mass flow rate was pretty constant over the Skylon's flight profile, varying only by a factor of 1.6 or so. However it's possible these bypass ducts change the overall picture. Even so, it cannot possibly replicate the crazy power rush of the RAPIER, since apparently the Skylon would need 2 hours to compete the air breathing phase of flight, reaching mach 5.2 or so at 22km. One other little fact slipped out during a discussion about nozzle design - apparently combustion chamber pressure doubles when switching to close cycle. I don't know enough about rocket engines, but i suspect power increases at least that much - sounds like a real kick in the pants...

A re-imagining of the stock R.A.P.I.E.R. engine, with brand new art to match the fantastic style @Porkjet has created. It's a separate part from the stock version, but it has the same stats and is the same size. Download from SpaceDock (1.2) Download from CurseForge (1.2) Download from Dropbox (1.2) 1.2 Changelog 1.1a Changelog 1.1 Changelog This work is licensed under a Creative Commons Attribution 4.0 International License.

http://www.bbc.com/news/science-environment-36773074 Many knew that it probably won't play out from the start, but this is a confirmation: apparently SABRE tech is now being pegged for an air-launch system. Which has its own unsolved challenges.

My first post on this forum. This is a replica of YSS-1000 Sabre from Halo: Reach. There're many difference from the one in the game because this is just stock and this is the best I can do. Roll and yaw are not very good but I never fly in atmosphere anyway Some specification Parts: 80 (158 w/ booster) Mass: 30t (130t w/ booster) Delta V: ~2000 m/s (closed cycle), ~4400 m/s (w/ booster), ~5000 m/s (air breathing RAPIER only) Engines: 2 CR-7 R.A.P.I.E.R. and 2 LV-T45 "Swivel" (Sabre) ----- 3 RE-M3 "Mainsail" (Booster) And a video. Nothing special, just the craft launching with Halo: Reach theme, this was before I do some modification to the Sabre and the booster.