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Squadcast confirms SABRES for 0.23!


Whirligig Girl

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The biggest balance problem they would face is the intake spam. Thanks to way-less-than-ideal airflow logic, you can put an intake on the tail to feed an engine at the front of the craft, which obviously wouldn't work anywhere but on KSP. As soon as they fix this, balance will be much easier to do, because you blocked one way of cheating or abuse and now the balance depends entirely on the stats of the part and not on possible exploits.

For the guy that said "intake ratios on real planes", there's no such thing as intake ratios to begin with. Even if an aircraft has 200 air intakes, the combustion chamber where air meets fuel is still a single one. The reason you need "more intakes" is because you need more air for combustion, not because you want your jet to reach higher altitudes. even so, planes with more than 2 intakes are really weird. Note that with intake I refer to "OPEN TUBE THAT LOOKS LIKE IT GETS AIR INTO THE ENGINE"

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Can someone tell me why these engines would be so useful? If they're less efficient than other rockets (like the LV-N), then wouldn't be better to just use turbojets and rockets more efficient than the SABRE? Even with the extra weight of having more engines?

Because you only need one type of engine; It can burn liquid fuel only while in an oxygen atmosphere, so you get the benefits of a jet - but then the *same* engine can be switched over to burn Fuel+Oxydizer like other liquid fuel rocket engines. This means you're not carrying the dead weight of an unusable rocket for half the trip and an unusable jet for the other half.

Less mass (and less fuel as a result), fewer parts, smaller craft.

=Smidge=

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Can someone tell me why these engines would be so useful? If they're less efficient than other rockets (like the LV-N), then wouldn't be better to just use turbojets and rockets more efficient than the SABRE? Even with the extra weight of having more engines?

Having 2 different kinds of engines doesn't add weight just because there are more engines.You will need to put the extra engines somewhere, you are going to need extra slots for them.That means extra weight added, more parasite drag, you will also experience changes in the aerodynamics, you might need extra lift to compensate and so on.

I might have exaggerated a bit, though.

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When I heard Sabre, I thought it would be something like an aerospike you tweaked yourself to except intake air and/or Oxidizer. If it was a dedicated part, then what would be the point of tweaking air intake? I think the game would be fine if a sabre was an intake on a rocket tank attached to an aerospike tweaked to accept intake air/oxidizer.

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Can someone tell me why these engines would be so useful? If they're less efficient than other rockets (like the LV-N), then wouldn't be better to just use turbojets and rockets more efficient than the SABRE? Even with the extra weight of having more engines?

A real SABRE can basically fill up fuel while flying. It separates O² from the breathing air and compresses it in its own tanks. So in theory, you launch with just a full fuel tank, and while you accelerate in the atmosphere you fill up your gas tanks. Once you have built up enough speed you can switch to "rocket engine mode", and gain the missing momentum you need for space.

For several reasons this is incredibly fuel-efficient. The most fuel is always burned in the lower atmosphere. Air breathing engines so far are insanely fuel-efficient, because most of the weight is carried by the wings, and not by thrust, and most of the fuel is gained directly from the atmosphere, but they are dead weight once you scratch the stratosphere. Vice versa, rocket engines are only really efficient once you leave the atmosphere, and until then are dead weight. This is why you usually need multiple stages to achieve orbit.

Even the Aeris IV is insanely fuel efficient. You can reach orbit, and land everywhere on Kerbin with just a single stage and some fuel tanks. And this is without SABRE.

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A real SABRE can basically fill up fuel while flying. It separates O² from the breathing air and compresses it in its own tanks. So in theory, you launch with just a full fuel tank, and while you accelerate in the atmosphere you fill up your gas tanks. Once you have built up enough speed you can switch to "rocket engine mode", and gain the missing momentum you need for space.

For several reasons this is incredibly fuel-efficient. The most fuel is always burned in the lower atmosphere. Air breathing engines so far are insanely fuel-efficient, because most of the weight is carried by the wings, and not by thrust, and most of the fuel is gained directly from the atmosphere, but they are dead weight once you scratch the stratosphere. Vice versa, rocket engines are only really efficient once you leave the atmosphere, and until then are dead weight. This is why you usually need multiple stages to achieve orbit.

Even the Aeris IV is insanely fuel efficient. You can reach orbit, and land everywhere on Kerbin with just a single stage and some fuel tanks. And this is without SABRE.

A more succinct post could not be written!

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If I'm reading the Wikipedia page right in the ~34.8 seconds I spent on it, this is an air-breathing rocket engine (workalike of KSP's jet engines) that can shut off the air intake and burn fuel+oxidizer just like a "normal" liquid-fueled rocket, yes?

That would be so cool! They giving any details on how it'll work, or do I have to be impatient for yet another update? Again.

Edit: Ninja'd by two people! I suck! :( C7's update exactly confirms what Wikipedia lead me to believe -- that's awesome and I might finally build my first SSTO! (Yeah, right! :P )

Yep, and I'm proud to say it's a British project... until we sell it to the Americans for two dollars and a Hershey bar like we did with the jet engine.

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Yep, and I'm proud to say it's a British project... until we sell it to the Americans for two dollars and a Hershey bar like we did with the jet engine.

Probably the Chinese. Like hell is any real British cash going into it ( other than the govt stake, looks good for the elections ), when was the last time that happened? if there's no immediate return, there's no interest...

I used to use B9 sabres for everything, but more recently I went back to seperate jets & rockets - our advantage is nuclear rocket engines, which is never going to be a real world thing. For really large spaceplanes I tend to use the B9 Sabres as jets - I've not seen a high speed jet remotely that big anywhere else - & maybe a few secs at a time in rocket mode as kick boosters, but I think the only reasonably recent design I've got with them as all engines is a smaller shuttle family with one of the large ones.

Happiest design family currently. Note one intake per jet.

9975467403_4a9ebdcb22_z.jpg

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Yep, and I'm proud to say it's a British project... until we sell it to the Americans for two dollars and a Hershey bar like we did with the jet engine.

And then we'll run away with it and make 150% better than you could have imagined it as well as integrating it into our culture, economy, and infrastructure almost seamlessly. Just like we did with the steam locomotive.

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A real SABRE can basically fill up fuel while flying. It separates O² from the breathing air and compresses it in its own tanks. So in theory, you launch with just a full fuel tank, and while you accelerate in the atmosphere you fill up your gas tanks. Once you have built up enough speed you can switch to "rocket engine mode", and gain the missing momentum you need for space.

For several reasons this is incredibly fuel-efficient. The most fuel is always burned in the lower atmosphere. Air breathing engines so far are insanely fuel-efficient, because most of the weight is carried by the wings, and not by thrust, and most of the fuel is gained directly from the atmosphere, but they are dead weight once you scratch the stratosphere. Vice versa, rocket engines are only really efficient once you leave the atmosphere, and until then are dead weight. This is why you usually need multiple stages to achieve orbit.

Even the Aeris IV is insanely fuel efficient. You can reach orbit, and land everywhere on Kerbin with just a single stage and some fuel tanks. And this is without SABRE.

Err, my question was that I was wondering if the SABREs would provide more Delta-V on an SSTO space-plane. How would a SABRE provide more Delta-V than a turbo jet and atomic engine (The delta-v after the plane has gotten to LKO)? Sure, a SABRE is really useful for huge planes and rockets, but I can't see how it will increase the range of an already long range SSTO.

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What do you mean never a real world thing?

The original plans for Kennedy also included the NAB (Nuclear Assembly Building). If memory serves, it was to be NE of the VAB, just north of the main crawlerway.

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I was wondering if the SABREs would provide more Delta-V on an SSTO space-plane.

Spaceplane has less engines so it's less complicated.

That pretty much doesn't change anything, but simple is better than complicated, right?

It will be probably lighter than 2 engines while providing (hopefully) same thrust.

That means more dV and better payload capability for small not huge spaceplanes.

I think specific impulse will be set at 360s while in vacuum, that's not really that different to 370s provided by LV-T45 (T30 and Aerospike 'cannot gimbal').

Rapier engines will not incrase range of long range SSTOs because they are not supposed to.

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Err, my question was that I was wondering if the SABREs would provide more Delta-V on an SSTO space-plane. How would a SABRE provide more Delta-V than a turbo jet and atomic engine (The delta-v after the plane has gotten to LKO)?

As long as Squad hasn't released any SABRE engine, no one can answer that. In reality the SABRE is an insanely powerful jet engine, especially in big heights. Or at least would be, up to now it was never tested on a real plane.

But that is not the reason why it is so efficient. Because it can basically fuel up in the atmosphere, it's almost like you would launch your rocket with full tanks from the outer rim of the atmosphere. Considering how much effort you need to leave the atmosphere behind, this is just amazing.

Sure, a SABRE is really useful for huge planes and rockets, but I can't see how it will increase the range of an already long range SSTO.

I disagree. I think, smaller SSTOs profit much more from SABRE than bigger ones. With a really big plane you can afford to mount multiple engine types without risking your balance or payload efficiency. But for a small ship a single engine that works as well in space as within the atmosphere sounds quite perfect.

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Regarding balance - should Squad now be focussing on balance for sandbox or career? For career, it'd be fine to have a highly-efficient & lightweight SABRE, if it was also very late in the tech tree & cost a tonne of cash. But for sandbox it would be overpowered, much like the aerospike was in older versions.

Everything will be changed at some point I suppose.

Career. You can't balance a sandbox mode that has all parts available, when the same parts are also used for career.

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And then we'll run away with it and make 150% better than you could have imagined it as well as integrating it into our culture, economy, and infrastructure almost seamlessly. Just like we did with the steam locomotive.

Woah woah woah, A4 Pacific http://upload.wikimedia.org/wikipedia/commons/5/5a/Number_4468_Mallard_in_York.jpg and full wiki page http://en.wikipedia.org/wiki/LNER_Class_A4 I strongly disagree with any statement that American steam locomotives are any percentage better than those of Britain.

On topic: Yay RAPIERs! I've been following the development of SABRE for some time, am very glad to see it getting some stock love in KSP :)

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