SSTOs! Post your pictures here~

[Sufficient Anonymity]

Nice design. It looks like the CoM would shift backwards as the tanks empty though - was this a problem? Every time I try to design something similar, I have trouble aligning the wet and dry CoM on the payload while still keeping the CoL behind both - my only solution so far has been to put a lot of empty space at the front to offset engines and wings being closer to the back.

No, actually - whilst I use TAC fuel balancer for everything, I'm pretty sure CoM and CoL stay the right way round even when draining to empty under the default fuel flow model - there are slightly more fuel tanks at the front of the craft, and all the power/RCS/guidance/docking is there, which helps keep the CoM forwards. The wings/engine pods were really carefully positioned in the SPH to balance properly.

EDIT: oh, and @Rune, thanks for the rep - I know about the B9 2.5m SABREs - I've got them on my B9 install, though I built this on my stockalike install, hence the use of Nert's Mk4 system etc and the wish for stock 2.5m spaceplane engines (on which note, @Blowfish, how's that Mk2 SABRE of yours coming along?).

EDIT 2: Well, this is awkward - I've flown in back near empty before, but never totally drained it - assumed it'd be okay. It isn't quite right. Have therefore pushed the wings back a bit more.

EDIT 3: And now I've made it totally unflyable :/

EDIT 4: Fixed it, with better balance than before -

Edited February 24, 2015 by SufficientAnonymity

[PCanas]

Rule of thumb; the more time you can spend on air breathing engines, the better. Assuming you're using FAR (and if you aren't, just forget the whole idea of spaceplanes), you can use its simulation window to get stability calculations for how your plane will fly at a range of speeds and altitudes. I suggest aiming for stability at 25km and mach 3.5, as this is (relatively) easy to achieve cruising altitude. If you can be stable at 25km and mach 3 or less, you are a god of design. My flight checkpoints tend to be:

- mach 1 or more by 10km

- mach 2.2 or more by 20km

- mach 3.5 or more by 25km

- hold at 25km until mach 5

- turn the nose up as sharply as is safe

- edge the throttle down, try to max out the available air until you're on the verge of losing speed again

- kick to rockets, pull the nose up; watch for pitch/yaw/roll instability, as a lot of planes wobble at this altitude

- at 50km (very little drag left now), point prograde and coast. Your AP may already be over 100km, but if not, just keep gently burning the rockets and watching your PE rise to meet you.

For something with stock parts, check out Wanderfound's excellent little Kerbodyne Dolphin as an example of an SSTO that requires very little effort to get into orbit. With care, you can nurse the turbojet all the way up to ~35km, which gives the rockets a serious advantage.

For heavier things, aiming for 30km on air tends to be about the best you'll get. Here's a heavy lifter SSTO I've been putting together using B9, just squeaking across the 30km barrier at mach 5 and ~60% throttle, with sufficient intake air (listed in the flight engineer panel on the left) to avoid asymmetric thrust. If you've got 3+ engines, this is a great time to kick some of them over to rocket mode, as it'll buy another few km from those that are still on air.

http://i.imgur.com/m1ZKL6C.jpg

Also, thrust to weight. Higher TWR will make up for a multitude of design sins by powering you through zones of instability faster.

Kerbal Engineer Redux will help with this - comes with a nice handy intake usage %. Turbojets suffer quickly, but rapiers will self throttle and generally kick themselves to rocket mode at the same time

Coool! The only thing I don't like are the engines in the front, but only for an aestethic reason.

Most of the planes I've designed have stability problems when reaching 25km. Plus, probbaly because of lack of thrust, it starts fo fall back down, ie, the prograde slowly falls despite maintaining the nose pointing up. Any ideas about the reasons for these?

[Rune]

No, actually - whilst I use TAC fuel balancer for everything, I'm pretty sure CoM and CoL stay the right way round even when draining to empty under the default fuel flow model - there are slightly more fuel tanks at the front of the craft, and all the power/RCS/guidance/docking is there, which helps keep the CoM forwards. The wings/engine pods were really carefully positioned in the SPH to balance properly.

EDIT: oh, and @Rune, thanks for the rep - I know about the B9 2.5m SABREs - I've got them on my B9 install, though I built this on my stockalike install, hence the use of Nert's Mk4 system etc and the wish for stock 2.5m spaceplane engines (on which note, @Blowfish, how's that Mk2 SABRE of yours coming along?).

EDIT 2: Well, this is awkward - I've flown in back near empty before, but never totally drained it - assumed it'd be okay. It isn't quite right. Have therefore pushed the wings back a bit more.

EDIT 3: And now I've made it totally unflyable :/

EDIT 4: Fixed it, with better balance than before -

http://i.imgur.com/8Qmdzh9.jpg

http://i.imgur.com/sVkwgwB.jpg

http://i.imgur.com/5t1KhhW.jpg

I caught this at work at around the third edit, and yeah, I was going to tell you the same thing you found out in the end: you probably had to move the engines forward, not backwards, to put the wet COL right where the dry CoM ends up. Thus Skylon's engines in the middle at the sides of the cargo bay, it's quite the elegant and simple solution. Heavy tail engines with a very light cockpit are the reason people have such a hard time balancing sleek-looking designs, they have to find out how to put the tankage and wing surfaces so it follows the same mass distribution as the empty airframe, or they will shift in flight. Even if they do that by trial and error xD. Also, it explains why canards are so much more effective than tailplanes for 90% of the designs in this forum, most of them are tail-heavy with CoMs quite a ways to the rear of the bird.

Rune. Still, deltas and chevrons look sleek indeed, and who am I to argue against their use?

[blowfish]

No, actually - whilst I use TAC fuel balancer for everything, I'm pretty sure CoM and CoL stay the right way round even when draining to empty under the default fuel flow model - there are slightly more fuel tanks at the front of the craft, and all the power/RCS/guidance/docking is there, which helps keep the CoM forwards. The wings/engine pods were really carefully positioned in the SPH to balance properly.

EDIT: oh, and @Rune, thanks for the rep - I know about the B9 2.5m SABREs - I've got them on my B9 install, though I built this on my stockalike install, hence the use of Nert's Mk4 system etc and the wish for stock 2.5m spaceplane engines (on which note, @Blowfish, how's that Mk2 SABRE of yours coming along?).

EDIT 2: Well, this is awkward - I've flown in back near empty before, but never totally drained it - assumed it'd be okay. It isn't quite right. Have therefore pushed the wings back a bit more.

EDIT 3: And now I've made it totally unflyable :/

EDIT 4: Fixed it, with better balance than before -

http://i.imgur.com/8Qmdzh9.jpg

http://i.imgur.com/sVkwgwB.jpg

http://i.imgur.com/5t1KhhW.jpg

Still looks like a lot of shifting to me. Do you have good pitch authority when the tanks are full and still have stability when the tanks are empty?

[Spartwo]

[Sufficient Anonymity]

Still looks like a lot of shifting to me. Do you have good pitch authority when the tanks are full and still have stability when the tanks are empty?

Pitch authority is alright, and it's a bit twitchy when empty, but if you're careful, it's flyable - I won't say it's easy to fly, but it's certainly not impossible (and hey, 104k for a 40 tonne lifter, most of which you recoup in recovery costs ain't bad).

[kopapaka]

[eddiew]

...

EDIT 4: Fixed it, with better balance than before -

...

http://i.imgur.com/5t1KhhW.jpg

What are the bits on thee front of the engine pods? That's a look I've definitely never seen before...

[NKL]

What are the bits on thee front of the engine pods? That's a look I've definitely never seen before...

It's from the OPT mod if you are interested. You can get it on KerbalStuff®, I suppose.

[hansen]

I finally managed to build two spaceplanes for heavy payloads. The first one is a drone capable of delivering an orange tank into a 100km orbit. The second plane can safely bring 36 kerbals into a 100km orbit.

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Edited February 27, 2015 by hansen

[micr0wave]

had one thing that flew right away on first rollout:

with nice cargo:

the dV readout isn't correct there are some fuelflow issues, maybe because the bays and cockpit are stock parts, i used it after this for a roundtrip to mün and minmus and back home without refueling, cargo was a bit less heavy but it actaully flies very well, re-entry you can just turn on SAS and let it fly alone for some time.

[Brownhair2]

B9 makes everything easier. That's my new motto.

Anyway, the Cancer (crab, not tumor) is a Mk 3 SSTO with a small cargo bay powered by 3 M SABREs (the plane, not the cargo bay. Although a detachable cargo bay sounds cool...). So far I've gotten it into an 85 km orbit, with plenty of spare fuel left. I'm guessing it could probably reach 100 km and still have enough fuel to get back. Stability-wise it's also pretty sound, although it seems to shake alot on takeoff. Next tests are with a payload.

Edited March 1, 2015 by Brownhair2

[Yakuzi]

As 1.0 will bring so many (craft-breaking) changes, I finally got around to finishing at least one of my SSTO's that have been under development since... 0.23 or something.

The Spectre spaceplane is quite a breeze to fly, can carry a decent payload to LKO (though haven't quite established just how many tons), has a custom designed cockpit and is fully stock. It still needs some final touches, but nothing major. For anyone interested, it gets to LKO using yer standard airhogger ascent profile.

Jeb and Bob were keen to take it for spin... so eager that they left before Bill could hop on. Poor Bill...

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[Vashts]

Falcon Class Trainer Space planes.

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craft files

Edited February 28, 2015 by Vashts
added link to craft files

[landfish2]

[fenya]

I performed a series of experiments and found out what engine has the best ratio of specific impulse and TWR

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Vashts, thank you

Edited March 1, 2015 by fenya

[Vashts]

[noparse]

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[/noparse]

is what you need. copy that into your post.

also new MK2 space plane im working on.

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Edited March 1, 2015 by Vashts

[Rezolution]

Ugliest SSTO I've ever made (whew, it's pretty bad), but it actually flies very well, stays balanced throughout the fuel burn envelope, and can make it to a 500K plus orbit with only four intakes. Calling it the "Slipstream." I thought it sounded better than "Pregnant Heifer."

Enjoy .

[LitaAlto]

The Trident SSTO Lifter, shown here in its "stock" configuration, is capable of lifting 8 tons to a 250 km orbit and then soft-landing back at the KSC.

(There is a SpaceY variant that uses landing legs better suited for the task, that cuts the overall weight by 6.4 tons.)

The .craft file is available at KerbalX:

http://kerbalx.com/LitaAlto/Trident%20SSTO%20Lifter%20Stock%20Edition

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[ScriptKitt3h]

The Excalibur, my first working (LV-N/TJ) SSTO in quite a while...

Also, I think I broke my all-time 'air breathing-flight-only' SSTO speed record...

[Rune]

I think it's been a long time since I posted one of mine here, so perhaps my latest will do. Can't let this thread lose it's awesome rhythm!

Ladies and gentlekerbs, feast your eyes in this marvel of engineering:

Looking sleek right? No point in doing awesome things if you don't look the part! Every detail has been polished, and every piece clipped with the smoothest finish, to hide all seams and struts and the like. And what kind of awesome things can you do with it? Well, this thing not only has a pretty face, it has legs. In atmosphere it is downright sporty, with low wing loading yet a high-ish TWR, while having a CoL close behind the CoM (that itself stays quite put, if anything it increases in stability as you go lighter to compensate for it) and ample control authority. Meaning it handles like a fighter, yet it will stabilize itself if you let go of the controls (if you have the time for it, of course). At high altitudes, the air routing solution will keep both engines lit as they spool down until one of them goes for good, and the nuke, while having lowish TWR, is more than enough to complete the push to orbit, and it makes the best out of the ample supply of fuel to give over 4km/s of delta-v from low orbit. With that kind of propulsion system (and I'll freely admit, some sorcery is involved), you can visit petty much any rock, if only to fly by it, and you can actually plant flags in a lot of places, including Laythe and Duna. Though I'm doubtful about safely landing on Duna without an additional VTOL system or some chutes, there is ample delta-v and TWR to try (note that the RCS system is placed where the CoM is, and it hardly moves).

And you do all that with ample crew space, at a ridiculous cost in fuel and with minimal part count! I actually use this obscene delta-v to perform what I call "rapid crew assembly" in my career save: train a lot of crews to lvl 3 really quick because I have launch windows to make and infrastructure to service. Goes like this, if you are interested: you take two standard crews (pilot, scientist, and engineer), zip off the runway, and if you burn the excess delta-v in a smart way (i.e: you do a fast-ish initial transfer to Minmus, but not too much into hyperbolic territory, and then you try to cut the travel time by flooring the pedal to the floor going outside kerbin's SOI and, especially, on the way back), have them put boots on Minmus, zip to outside kerbin's SOI, then turn around and scream back to base flying by Mun with all the m/s you can manage while timing it right so the Mun is in the right place when you cross its orbit. I've completed such a tour of the kerbin system in about two weeks, kerbal time, which is somewhere between three and four Earth days. Minimal delta-v Minmus missions are longer than that!

IMGUR ALBUM:

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DOWNLOAD:

http://www./download/k9htahbmbh7su5c/SSTO+Mk+XLIIIb+-+Spatha.craft

Rune. R-SUV needs more SSTOs!

[B.O.B.]

One of my career-save SSTOs.

I use this one for nearly all the interplanetary sat placement contracts while training my newest kerbal recruits at the same time...

47.5 t

up to 6 kerbals and nearly anything you can fit into the cargo bay^^

2 Turbojets

2 R.A.P.I.E.R.s (rocket mode used mainly for extra thrust while lifting heavier loads)

2 LV-Ns

~ 4.2k deltaV after reaching LKO (less if launching heavy cargos of course)

~ 5.2k deltaV if fully refueled in orbit

(~ 70 deltaV RCS)

Excursion to one of Laythe's beaches after delivering a satellite to Jool

Jeb and Bob returning from a test flight (it's a stable glider, so you only have to time your decceleration burn right to do a completely unpowered landing at the runway...)

- - - Updated - - -

And another one... Originally designed as a stylish way of transfering kerbals between planetary stations (and back down to Kerbin eventually), until i found the easiest way to get it into orbit was adding 2 turbojets ^^

in orbit (with atmospheric engines decoupled) - it reached LKO in one piece. so it's still a ssto, isn't it?

[pheeph]

I built this ship from the Duck Dodgers TV series.... It's based on the Protectorate ship Duck Dodgers and his space cadet fly in...

[Corscaria]

I've lost the craft file to this when a HD burned, as well as the full res screenshot. But here's my SSTO space train.

[Mr Tegu]

New VTOL SSTO, thinking about weaponising it: