Skylon. Welcome 0.25!

[Rune]

Yup, Spaceplane Plus totally made this possible. And THIS is what the MkII cargo bay was made for:

I've got to say, the guys at Reaction Engines do know how to design a bird. I had to cheat a bit because KSP aerodynamics, but only a TINY bit (two clipped control surfaces on the back to bring CL backwards). Other than that, no hidden magic: two intakes, two fuel lines, no other clipping at all anywhere and just a couple of struts to keep it firm. And it draws fuel perfectly fine! CoM doesn't move at all during all the flight, and cares not about the payload you put in there since it's right in the middle of the bay. The 5.1mT test payload means that for very little fuel, you can lift a considerable fraction of your takeoff weight to orbit (>25% of GLOW as cargo!). The only difficult thing about the design was actually lifting off: rotation speed might be ~70m/s, but actual liftoff with the clearance it has takes about 105m/s, the clearance to get enough angle of attack is a couple millimeters (if the tail wasn't raised, you wouldn't be able to take off before the lip of the runway), and I was insisting on doing it by hand.

Very true to the original of course, which also has an insane wing loading when full, and taking off at similar speed! Which might be great for the replica part, but the number of tailstrikes before I convinced myself I just wasn't a good enough pilot was horrifying. In the end I added an extra wheel on the tail to make it impossible to leave parts on the runway... fortunately for my test pilots it's unmanned!!

Having said that, I did it mostly because the new parts were screaming at me to do it. I just had to. Now I only need to find an excuse to incorporate it in my space program. Hope you guys like it! Here, have some more pics:

The test flight was priceless (check the end of the album!): I didn't have to load once, and even though I undershot KSC by about the whole KSC continent (I was dropping short of the mountains), the remaining ~40l of fuel lasted me to within a couple kms of KSC at a couple hundred meters, so I could also test another thing: it can be landed with a full load and no engine power at all if you run the tanks dry. And I was so close, with the remaining momentum I made it to the runway. Yay me!

IMGUR ALBUM:

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DOWNLOAD:

http://www./download/c6fviz31h5aha5w/Skylon+C1.craft

Rune. One would think I planned it! One would be wrong, though...

Edited October 8, 2014 by Rune

[Majorjim!]

Hi Rune,

I was thinking about a SP+ Skylon, you ninja'd me! (busy with something)

Looks cool and now that the pods have lifting bodies its much easier to make something like this.

MJ

[Rune]

Hi Rune,

I was thinking about a SP+ Skylon, you ninja'd me! (busy with something)

Looks cool and now that the pods have lifting bodies its much easier to make something like this.

MJ

I was actually surprised nobody nija'ed me! The new adapters are just the same aspect ratio, and the aerodynamics work almost perfectly to give you a "if it looks like the thing, it'll fly like the thing". I was very surprised when I worked out the takeoff speed in km/h and got RL Skylon's 300 and something! And doubly surprised when it didn't land hard enough to break anything unpowered and without the best flare (considering I wasn't expecting to run out of gas 50m from the ground, you can see why it was a big surprise, I panicked, pulled back, climbed, lost all speed, then dropped with the highest angle of attack I dared and expected explosions... it didn't even bounce appreciably!).

Rune. Now that I think about it, the version flying in the pics is slightly different from the one I uploaded, because I refined things a bit further looks-wise. Check the album for profiles!

Edited October 8, 2014 by Rune

[Majorjim!]

Phew sounds like an exciting landing.

How do the lifting body pods handle? Do you need to flair a lot on landing?

[Frozen_Heart]

You must spread some Reputation around before giving it to Rune again.

This text has become a familiar sight over the last few years.

Really nice looking replica. I'm really surprised it can take off with such tiny wings!

[EladDv]

what a beautiful craft. amazing

[Rune]

This text has become a familiar sight over the last few years.

Really nice looking replica. I'm really surprised it can take off with such tiny wings!

Thanks, but it's true what the message reads, spread the love! Newbies need encouraging, and half my ability is practice As to wings, read the next comment!

Phew sounds like an exciting landing.

How do the lifting body pods handle? Do you need to flair a lot on landing?

Actually, the plane parts have a lot more lift than I expected, about a bit more than half of what a single of the old structural wings had (0.6 lift rating). That means that empty cargo bays and, especially, empty fuel tanks, are almost like wings themselves. 100% lifting bodies will have trouble offsetting crew cabin weight, but a couple canards and I expect to have survivable landings on, basically, a MkII crew cabin... now that I think about it, hold on a bit, I have KSP open...

Rune. You had to do that.

[Rune]

Phew sounds like an exciting landing.

How do the lifting body pods handle? Do you need to flair a lot on landing?

Yup, totally doable. With a bit of a flare, I managed to get a drop rate of about 15m/s at touchdown, which the wheels survived, on this:

Rune. 45º on the lifting surfaces, so technically they aren't wings.

[Majorjim!]

Yup, totally doable. With a bit of a flare, I managed to get a drop rate of about 15m/s at touchdown, which the wheels survived, on this:

http://i.imgur.com/HWAXXzo.png

Rune. 45º on the lifting surfaces, so technically they aren't wings.

Ha! That's awesome news!

Flying by the seat of you're pants, just as I like it!

[emaier138]

Love it, I was looking forward to your first .25 SSTO after I fell in love with your white dart and Nodachi (which I still cant quite get to orbit).

I almost exclusively built in the VAB before discovering your SSTOs. But with .25 I'm only building SSTOs in the SPH, I got one perfect, but cant seem to get my payload lifter to get back after leaving the payload in orbit.

[Rune]

Love it, I was looking forward to your first .25 SSTO after I fell in love with your white dart and Nodachi (which I still cant quite get to orbit).

I almost exclusively built in the VAB before discovering your SSTOs. But with .25 I'm only building SSTOs in the SPH, I got one perfect, but cant seem to get my payload lifter to get back after leaving the payload in orbit.

Hey! I missed this. But then someone "graded" the thread (it's always funny when someone gives the single star to a thread that has given me over 30 rep so far ), and I saw it again, I guess we should thank him whoever he is.

Don't sweat it a lot about not getting the Nodachi to orbit! The full orange tank is right at the limit of its payload ability, so it requires a very good ascent profile to not fall short, and that takes a bit of practice (basically, you need to get it really fast, over 1,400m/s at around 30kms, before you get the first flameout and the RAPIERS switch, then build up vertical speed, and watch out because the second flameout can spin you). I suggest you try with smaller loads until you get the hang of it's airhogging altitude and profile (when I rebuild it of course, although it still kind of works, I just have to move wings around a bit to get the smooth lines back, and probably a bigger cargo bay if I mess with the engine pods). I might even put a cargo door on the Mk II...

And as to the White Dart, I am working on a new version that has little if anything to do with the original. It will look nothing like it, but it's almost as good if not better in every aspect. We'll see how you guys like it! Hint: it'll have an interchangeable "mission module" instead of several versions, and a 100% static CoM right in the middle of it.

Rune. I think I can say I have fuel flow rules mastered

Edited October 10, 2014 by Rune

[Guest]

Just to let you know, you can play around with the canards' angle of incidence (basically, tilt them forward or backward) in order to balance COL without clipping winglets in the back.

[SpaceXray]

Just to let you know, you can play around with the canards' angle of incidence (basically, tilt them forward or backward) in order to balance COL without clipping winglets in the back.

Agreed. I always clip these small control surfaces inside and then disable some controls on them to avoid weird control issues.

[Rune]

Just to let you know, you can play around with the canards' angle of incidence (basically, tilt them forward or backward) in order to balance COL without clipping winglets in the back.

Yup, that would be a thing to do. But my wing loading is already through the roof, and even though they have a (very) long lever arm, those canards don't provide that much torque (and are the only control surfaces visible with pitch control enabled). The rear winglets (which are no longer visible, BTW) not only bring the CoL right behind the center of the bay (where CoM is through the flight), they also increase pitch authority greatly so it can maintain 45º AoA's on SAS without sliding, AND bring up total lift, making it able to lift off before the lip of the runway. I already have a takeoff speed of over 300km/h...

As to the angle itself, yeah, theoretically that would make sense. As well as angling the engine and intakes, and the wing itself while we are at it. But not only would I kill the looks, those kind of tricks have to be tailored to a specific flight condition (low speed-low altitude or high speed-high altitude). Some are dominated by thrust, some by lift, and it is literally impossible to balance for both even in RL. Which is why I went with the totally doable, 100% symmetric KSP vibe that never gets you any unwanted torque. Not realistic, but then again KSP aerodynamic model. Nuff said.

Agreed. I always clip these small control surfaces inside and then disable some controls on them to avoid weird control issues.

No lifting surface in this build has more than one control axis enabled (I still get occasionally some very slight, very weird oscillations at high altitudes in yaw due to transient asymmetric thrust that can somewhat amplify under SAS if you don't intervene... what can I say, I went really light on yaw authority)

Rune. It looks deceptively simple, especially since the flight test pics are from the prototype. DL and take a proper look inside the hood!

Edited October 10, 2014 by Rune

[LaDouche]

Hey!

Really like this one, my favorite Skylon here so far.

I hope you don't mind, but I did some modifications on your craft, what do you think?

I might have gone a bit overboard on the intakes. Still not entire sure what I'm doing with SSTO's. Lots of trial and error...

Anyway, thanks again!

[Rune]

Hey!

Really like this one, my favorite Skylon here so far.

I hope you don't mind, but I did some modifications on your craft, what do you think?

I might have gone a bit overboard on the intakes. Still not entire sure what I'm doing with SSTO's. Lots of trial and error...

Anyway, thanks again!

http://i.imgur.com/tBU1elK.jpg?1

I think that's the best thing that can happen to one of my crafts once I release it, that someone takes it as a point of inspiration and makes it his own... and he comes back here to show it! So thanks for the screenie, and I hope you have fun with it! As to intakes, I actually have to engage in a bit of a test program myself... I have a hunch something changed with the last update, but I haven't had the time to check with a model I already know the performance of. Used to be the more intakes you had, the more performance you got.

Rune. More on that later!