I think the RAPIERs are a bit overpowered now...

[SkyRender]

Just a little. I launched this thing on a whim to see if it would be able to reach orbit, and the answer was "yes, embarrassingly easily and with much fuel to spare".

[Wanderfound]

Get yourself FAR. The most recent update nerfed the thrust of all the air-breathing engines by 50%.

If you're using stock aero, you're swimming rather than flying. Standard atmosphere is absurdly dense.

[Levelord]

I've noticed similar changes. This is coupled with the fact that their weight has been drastically reduced and weighs the same as a turbojet engine. Meaning it has the advantages of atmospheric ISP flight and thrust in vacuum without the weight disadvantage of using a jet engine/rocket combo.

The jet/rocket combo has been effectively made obsolete in the recent build of KSP and I have to refit all of my SSTOs with RAPIERs.

[FenrirWolf]

Rapier fuel consumption still feels really high to me once you actually do the switch to rocket mode. But maybe that's because I like having planes with LV-Ns if I'm doing a turbo/rocket combo

[Rithsom]

Yeah, the RAPIERs are waaay too overpowered now. By having a mass of only 1.2, having both jet and LFO engine functionality, and decent Isp, these should cost a lot more.

[Bean]

I haven't unlocked them yet in my career, but jets in general seem way OP now, I can get any payload to 150x 35km orbit on jets alone.

[ansaman]

Personally, I enjoyed being able to get a spaceplane to orbit and land it although it took a few tries to get a configuration that would land without skipping down the runway (too much lift).

[Cirocco]

wait, RAPIERS were updated? when did that happen? I seem to have missed this one.

Damn, with RAPIER updates, nacelle updates and all the other stuff I'm going to have to completely re-design just about all of my spaceplanes, half their parts got updated...

[SkyRender]

Personally, I enjoyed being able to get a spaceplane to orbit and land it although it took a few tries to get a configuration that would land without skipping down the runway (too much lift).

A tip for smoother overall spaceplane trips: have your fuel placed to the sides of the fuselage, as shown in my first post, and use tweakables to adjust fuel levels and see how it measures with the craft's center of mass. Get it as close to perfectly centered as possible (ie. fuel drain won't shift the CoM), and as long as your center of lift is correct, you won't have any problems. Related tip: do this BEFORE you add landing gear; despite what the CoM indicator claims, landing gear is currently physics-less and will not in fact adjust your CoM at all in-flight.

[Red Iron Crown]

It's still not as efficient as a well-designed turbojet/rocket hybrid is, the higher air-breathing Isp of the turbojet can easily offset the mass of a couple of 48-7Ss. I'm glad it got a bit of a bump, I basically never used it prior to 0.24 as it was totally outclassed by the turbojet/rocket combo, now they're more competitive.

Also, in before the inevitable "Think it's overpowered? DON'T USE IT" replies which seem to plague any thread about part balance.

[ansaman]

A tip for smoother overall spaceplane trips: have your fuel placed to the sides of the fuselage, as shown in my first post, and use tweakables to adjust fuel levels and see how it measures with the craft's center of mass. Get it as close to perfectly centered as possible (ie. fuel drain won't shift the CoM), and as long as your center of lift is correct, you won't have any problems. Related tip: do this BEFORE you add landing gear; despite what the CoM indicator claims, landing gear is currently physics-less and will not in fact adjust your CoM at all in-flight.

Thanks for the tip. The first successful landing, I had to move fuel around to get a proper CG. Actually, this is critical in many real-world flight situations. Bad Center of Gravity can get you killed.

[Renegrade]

Related tip: do this BEFORE you add landing gear; despite what the CoM indicator claims, landing gear is currently physics-less and will not in fact adjust your CoM at all in-flight.

Note that some mods correct the CoM for physicsless parts; I believe RCS Build Aid and FAR both have better CoM handling than stock.

[SkyRender]

Okay, I think I've topped the absurdity factor for now.

Thank you for flying with Airbus Kerbin, with service to low-Kerbin orbit. Please keep your arms and legs inside the cabin at all times, and keep your seatbelt fastened until the captain has turned off the seatbelt sign. In the event of an emergency, your seat may be used as an EVA jetpack, but it won't help you survive re-entry.

[TheScareCake!]

I still hate to use them! Aerospikes for the win! ^^ And you cant even use them on interplanetary voyages, lv-n are the thing!

[Laie]

Okay, I think I've topped the absurdity factor for now.

My Laythe Lander has an empty weight of 13t and needs two of the smallest Rockomax tanks. Yours is like two or three times as heavy and needs four times as much fuel. Not bad, for Rapiers. But not absurdly economical either.

[SkyRender]

My Laythe Lander has an empty weight of 13t and needs two of the smallest Rockomax tanks. Yours is like two or three times as heavy and needs four times as much fuel. Not bad, for Rapiers. But not absurdly economical either.

That spaceplane's 34.308T when empty, so it's around 2.6 times heavier than your Laythe craft. Of course, it's kind of irrelevant given that the goal here was to see how much I could do with 1 orange tank equivalent on Kerbin, not on Laythe. I'd say a payload fraction of 25.88% to LKO with RAPIERs alone is nothing to sneeze at.

[lammatt]

True, ferram nerfed the thrust of the jets a lot.

(but left the basic alone.. which is lame, it's still 175kN max when the turbo jet is 110kN max while the B9 jet is 115kN max... )

[Madrias]

I'm enjoying the use of the RAPIER as a dual-mode assistance engine. It pushes me to stupid altitudes on jet power alone. It kicks over to be a rocket and burns up the little bit of fuel I let it use. Then I kick the LV-N's in the butt and fly into a nice calm orbit.

[Renegrade]

True, ferram nerfed the thrust of the jets a lot.

(but left the basic alone.. which is lame, it's still 175kN max when the turbo jet is 110kN max while the B9 jet is 115kN max... )

Static thrust for a jet engine is largely meaningless. That's the number you see in the VAB. It's like say, taking your weight, and using that as your only meaningful stat. Not really accurate, eh?

The Basic's power curve drops it off to zero at around Mach 1, whereas the TurboJet's drops off in the hypersonic regime (around Mach 6+)

The TurboJet might be a little slow off the runway, but that means little when you're at Mach 5 above 23,000 meters...at which point it's only generating like 8% of it's static thrust, or two LV-1 "ants" worth.

It looks something like this (very approximate):

Which would you prefer on your spaceplane?

Trust me, Ferram knows what he's doing.

[lammatt]

No he doesn't.

[Renegrade]

No he doesn't.

Am I supposed to reply with "Yes he does" here.. ?

[prophet_01]

Isn't the whole point of rapiers to enable good looking and efficient small and medium sized ssto's? A combo of highly specialized engines will always win in terms of isp. But the craft needs to be big enough to get any advantage. I wouldnt even consider using rapiers on a bigger transport ssto.

The update update just shifted the level at which specialized engines are the better option a bit. I am ok with that

[FacialJack]

Blonde have Moar fun

My ship have Moar engines !!

Moar engines Moar brute power Moar good looking !!

[CaptRobau]

If anything turbojets are overpowered compared to their real-life counterparts. The TWR and high speed performance are more akin to a ramjet, then a turbojet. It's difficult to fix though, since KSP badly models airbreathing engines (because it uses systems that only model rocket engines well). A real RAPIER (SABRE engine) is supposed to be worse than an individual airbreathing or rocket engine, but because you don't have the weight of three engines (two rockets/two airbreathing or vice versa) it is more efficient when you need both airbreathing and rocket modes.

[Raptor9]

FacialJack, what visual effect mod are you using for your engine exhausts? Those turbojets look sweet.