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Pre-Whiplash SSTO Spaceplanes: Possible? [Yes!] Tips?


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Hi!  One thing I've always tried to do, and most always failed at, is "SSTO" spaceplanes.  In probably 1.0x, or even 1.2x, I achieved it using a design from a Scott Manley vid.  It was pretty close resource-wise, the fuel left over once orbit was achieved made the whole thing fun, but rather pointless...  I've got the KSP bug again and got back into a new career game.  I've unlocked the afterburning "Panther", and I seem to remember it being possible to reach orbit using two of those, with two LV45s (or 30s... not sure).  The plane had ~1800 liquid fuel total.

 

So since then I've tried again, with less fuel, to see if that's a change in 1.4.4, total vessel weight is 29 tonnes.  I ought to post my design, will do later on.

 

But, it just doesn't seem remotely possible, at least for me :P  anymore.  With trying to minimise wing drag, it barely has enough lift.  Forward canards helps that, but all my planes have an annoying pitch-bounce with that.  Thrust drops so much, at such a shallow ascent angle (5-15 degrees), I can barely get to 10,000m, much less ~300m/s at such an altitude in preparation for going higher and faster.

 

It's kinda dumb, I'd really like to spaceplane :(  How do you do it these days, in an early-ish career?

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Keep it simple - really simple. Ruthlessly strip away anything that's not necessary in order to minimise drag and mass. For example, do you need that rudder? A fixed stabiliser can suffice. Here's a primitive SSTO:

dCJQFRg.png

 

Some specific tips:

  • Add some incidence (1 to 2°) to your main wings. This will help generate lift while reducing drag by keeping your body more prograde.
  • Experiment with different ascent profiles to get the most out of your design.

 

Some threads that might help:

Caveman Tech SSTO Challenge

Tech level 7 SSTO to Minmus surface and back

 

 

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As you can see in the caveman tech SSTO link given by ManEatingApe, LVT-45 and LVT-30 can both singlehadledy  launch a crewed capsule in a single stage rocket.

I remember once trying to do a spaceplan SSTO using a single LVT-30. It had no wings, only two pairs of winglets.It was heavier than its rocket counter part, much harder to fly and land, very long to design, and not more useful. So if you go rocket engine only, save probably for the aero spike, you're better off with a rocket SSTO than with a spaceplan SSTO.

 

If you want to use the basic jet engines (juno ad wheasle), I think they changed a lot. You used to be able to go up to 10 km and still have decent performance. I think they start to flame out at 10km now. Now with them you want to accelerate as most as you can barely above sea level before pitching up (going fast also increase air intake and make them flameout later).

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It's possible to make an SSTO with 3 junos and 3 spark engines: 

There are a lot of tricks to making an SSTO. But a panther engine should always be able to get you to 800m/s at 15km altitude. If your design can't reach that minimum, then you have a drag problem. If you have a drag problem, it's most likely because you haven't looked closely at the drag values of all the parts you are using, or you haven't realized a few small but important details about the KSP drag model.

To know the precise nature of your drag problem, we'd need pictures. And we'd need to know which rocket engines you have available.

 

 

Edited by bewing
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Thanks a lot for the replies, all.  This is my prototype design.  I have Supersonic Flight researched, but not Advanced Aerodynamics.

The basics of what I've intended for it to do, is to get to orbit with a "pretty small" payload, and a 3 Kerbal capacity.  I guess 3 because I've had a tough time flying with any but a Pilot, a Scientist to operate the experiments that need restoring, and an Engineer to let me play around with KAS and I'm anticipating working on a station of sorts.

In my career I recently upgraded to Level 3 SPH, and also have Level 2 VAB and R&D.  So I guess really, funds aren't too much of a "concern" going forward, though I use the setting where I have to buy my parts once researched.  But I just like the concept of the efficient, reusable spaceplane to LKO and beyond, so that's what I'm trying to do.

AIqpLHd.png

 

It's interesting the different designs in the Caveman and Tech level 7 threads.  Seems fairly common for engines and some of the fuel to be on the wing tips, for example.

A definite observation I have is that I don't know a lot about the drag model, the lift values of the parts (other than the "Relative Lifting Area" in the hangar view), what sort of TWR and Delta-V values I should be looking for.  So, I'll go to further tutorial and how-do-even-KSP threads ;)

I looked through Basic Mk2 Spaceplane Guide and it was very interesting.

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Initial impressions: Bad choice for cockpit. That one is heavy, and has very low heat tolerance -- it is likely to blow up on reentry. If you use the inline one, you can put an air intake on the front of it, and get rid of the two on your nacelles. (Replace them with NCS tanks.)

Is that 2 Swivels back there? That's one too many. Get rid of the bicoupler, and either taper down to a single engine, or just stick the one engine straight to the node on the back end.

You have no incidence on your wings. A few degrees makes a huge difference.

That little RCS tank in the back should probably go inside the cargo bay.

The tail is way too big.

The final version is going to need an antenna and a solar panel. (Again, inside the cargo bay would work.)

If you are willing to be non-traditional, a 1.25m fairing makes a much better cargo bay than those MK2 parts do.

 

Edited by bewing
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For the "cockpit", use a probe core inside a 1.25-meter service bay. It is highly resistant to pressure, temperature, and impacts. Mark 2 parts are...interesting in an aerodynamic sense. They generate lift, but a lot of drag. Try to use rocket-sized adapters and 2.5-meter cargo bays for your payload. That RCS tank is, indeed, an aerodynamic nightmare. Use a 1.25-meter or 0.625-meter rocket RCS tank built into your craft.  Try offsetting Communotron 16-S units into your wings for aerodynamic and activation-free communications and data uploads.

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Thanks again for the input.

 

I moved the two spherical RCS tanks from the top and bottom of the tail into the cargo bay (I don't have the stack mounted ones yet).  Dropped one of the LV-T45 Swivels and changed the bi-coupler to the 2-1.25 adapter like I have at the front.  Mk1 cockpit to the inline version, with a third intake on the nose.  I don't know if that's too many intakes and would be bad for drag?  I know as much that you don't need to "spam" intakes anymore and in fact too many is bad.  I'd simply forgotten solar panels, but there's a Communitron 16 snug inside the cargo bay that's hard to see in the image.  I don't quite know the degree, but I've added a little incidence to the back wings.  I think I'll need to add a bit to the front-most strakes.  Not sure if I have a replacement for the tail wing, other than a smaller, but non-control winglet, then I figure I'd have no (effective) yaw control?

 

With adjustments based on the replies, and looking more at the thread by AeroGrav that I linked above (may be a little old, but it seems pretty good info), I think this craft certainly can do it.  At least, I've got it to space altitude with a fairly long sub-orbital trajectory.  I'll perhaps need a bit more fuel and/or a better-executed flight profile.  I also found the Aero GUI, and so many things make so much more sense now, haha!

 

It's pretty cool to see the impact a small change can have.  I was just getting frustrated ;)  That said, aren't spaceplane SSTOs one of the harder things to do and get right?

Edited by Doslidnyk
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5 minutes ago, Doslidnyk said:

That said, aren't spaceplane SSTOs one of the harder things to do and get right? 

Yes, but. You're starting small and are content if you can get to orbit and back. Which already is a bit of work:  Be honest, designing your plane was a lot more effort than coming up with a rocket to serve the same purpose. Flying it also is more difficult than a rocket & ballistic return vehicle.

A lot of people only get into spaceplanes once they have a need to regularly ship large and heavy payloads and/or want to get to faraway destinations right away, which exposes them to a lot of problems, many of which you're not having yet, all at the same time. That is indeed a steep hill to climb.

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I would also caution @Doslidnyk to watch out for his CoM/CoL balance, as it looks like that will become unstable with low fuel? As for the question about needing yaw input - you will be surprised but actually you can get away with a fixed vertical stabilizer in a lot of cases. Yaw control makes spin recovery easier, but to turn a plane you should bank and use the elevators to bring the nose around (and if you have yaw control you use the yaw to keep the nose up while turning) so it is not essential. 

If you're still having issues with this, post a kerbalX link to the plane, and I would gladly take it for a spin and see if I can come up with some design revisions for you. (Also maybe post the save file, or at least an image of your tech tree so I don't use parts you don't have yet) 

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It can be more effective to ditch the jet engines for early tech spaceplanes. Use the mass saved by leaving out the jet engine and intakes and throw in more rocket fuel. The amount of speed and altitude you get from early jet engines is often not worth the mass penalty.

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SSTO spaceplanes are possible using very crude tech, but I don't consider them to be truly practical until you've unlocked the Panther. The tricks to it:
-Don't rely on raw thrust, rely on clean aerodynamics. Don't take more engines than you actually need. Same goes for intakes.
-Don't design your spaceplane to do any more than to deliver passengers and supplies to LKO. The high efficiency engines and additional fuel just reduce your payload fraction, and airplanes make lousy spaceships.

Best,
-Slashy

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At one point I figured Mark Thrimm was the pinnacle for low tech space planes. Shows what I knew... these days I can follow Andetch's example and build an orbital trainer out of Tier 5 parts.

Keep in mind I'm taking advantage of Ferram Aerospace Research to reduce the wing mass and get a little more liquid fuel for those Wheesley turbofans.

With some pruning I could fit in a service bay and two science instruments.

More realistically, I can take four to five tonnes to LKO in this:

This was also a better example of re-entry than I previously did with this particular craft.

So, definitely, pre-Whiplash SSTO craft are possible, and even practical once you have access to Mk2 cargo bays.

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https://kerbalx.com/AeroGav/Basic-Tourist-SSTO

Panther Terrier 30 part ship - 3 seats to LKO.

On a technicality , this also counts as a "pre whiplash SSTO".   Liquid fuel only panther/nerv thingy that can go a bit beyond LKO actually.   Beyond the NERV motors, the rest of it is pretty much caveman.

https://kerbalx.com/AeroGav/Stretch-Ray

sOK1Q7w.jpg

BTW,  I like plenty of wing, especially when you have TWR < 0.5 in upper atmosphere thanks to NERV engines.  Hypersonic motor glider, that is what you are building.

4 Star Euro NCAP Rating too,  protect your most experienced Kerbals !

 

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Hah those are some cool planes, and showing how it's done!!  After following suggestions, moving components around, there were definite improvements.  Not quite there; but much closer.  I am starting to think, this is becoming as much about stubbornly "solving" it than any major in-game gains this will achieve ;)  Test runs have either ended with fuel out at an impressive, but decidedly sub-orbital trajectory; or orbit was not quite there, but possibly within reach - yet resources were so low I thought nah.

 

BUT.  I went and installed Editor Extensions Redux (props to @linuxgurugamer for the flag-carrying and @AeroGav for the suggestion in your Mk2 guide thread).  I snapped my main rear-most wings and front canards to 2 degrees.  I don't know what the wings had before, but it was fine-rotation guess work, and I'd not applied it to the canards either.  When I replaced the wings I'd left off the two 4-way wing-tip RCS thrusters, so that was a test a few less drag-inducing parts I suppose.  But the little docking port's still there.

 

@Andetch You were right about the balance, all previous test runs were very much threatening to backflip.  I think that's improved now.

 

Here's what I ended up with - for the moment, at least.  That graph though....

vG91M37l.png

tAUcskgl.png

WBcglm4l.png

Nice graphical anomaly at launch.

It still has very high drag values, and AoA is often >4.5ish at the lowest, but I can't help but think that little bit of more-precisely-controlled incidence to both canards and wings made a huge difference.  Before AoA was quickly >6 at the lowest, and more when faster and higher.  I watched control surface authority limits too, and that seemed to also have a fairly large impact.

ZO7IAVFl.png

N1cXxwAl.png

VeQZBLkl.png

And I Jeb made it :D  to an orbit, at least.  He says thanks, I think.  I don't speak his language, but he looks rather chuffed.

I say many thanks, too, for the tips here and other threads, mods, tools, videos.  Now to uh, take it back down and see how it handles that..  Assuming it doesn't end with fire, I'll put RCS back and beyond that look at modifying payloads.  It's exciting.

Edited by Doslidnyk
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1 hour ago, Doslidnyk said:

- SNIP - 

Well done for making orbit! Still looks like the Com/CoL might be a bit flippy.... CoL should be behind CoM. Where you have it will be very maneuverable but unstable. No sure how it will end up on re-entry....

About lack of resources in LKO - you will see from my Cavetech Spaceplane that it get's into LKO with around 10 units of fuel left - so really as long as you made LKO it doesn't matter :) You can always have a tug up there to RV and move the plane around after! 

Edited by Andetch
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On 6/24/2018 at 11:09 AM, Doslidnyk said:

I think this craft certainly can do it.

From the first screenshot you posted, I thought so too. It looked very close to being capable of meaningful LKO operation. Since a lot of the (generally good) advice given suggest rather hefty changes to your craft, I decided to see how close I could stay to your own design and still make it work. Whether I succeeded in keeping to your original concept will be debatable, but I think it at least showcases a few basic tweaks for spaceplane construction.

A cave at: I rebuilt your craft in 1.3.1 from the first screenshot you provided, since you didn't share the craft file. Some things can't be seen well enough (cargo bay content) or at all (main gear placement/configuration) so I had to free-form those parts.

Tl;dr: the Prototype 2B (note: link updated) carries a 2.3t cargo to a 100km orbit with full (extra) mono tanks for rendezvous and docking operations, spare LFO for orbital maneuvering and reentry burn, and a bit of extra LF for powered flight time on the return. It's also easy to keep stable, even with empty tanks - with all other tanks empty, using the last 50-ish units of mono does shift the CoM a tiny bit behind the CoL, but it can still be controlled well, and in normal operation this should hardly ever happen).

Spoiler
On 6/24/2018 at 1:39 AM, Doslidnyk said:

AIqpLHd.png

O1znz8i.png

Original and rebuild. Did it keep the lines sufficiently?

3XDAD5G.png

Gets to LKO with ease with a 2.3t payload and still plenty of mono/LFO to spare.

FhtUmRH.png

And makes it back safely (with payload too!).

I first rebuilt it as closely as I could to yours, to keep track of what I ended up changing. A list of the changes, more or less in order of positive effect:

  • Your craft was sorely lacking lift, even with added AoI - so I replaced all six (visible?) wing sections by bigger ones: delta wings in the rear and structural wing type A for the two forward sections. With double the trailing wing edge, I also replaced the single elevon-1 by an elevon-2 (roll) and elevon-3 (pitch), for separate roll/pitch control and more control authority.
  • Angle of incidence on the wings. A very simple yet very effective improvement. For a spaceplane, you can simply start (and often suffice) with giving the rotate gizmo one fine 'click' (5 degrees) of positive incidence. I did this to all the fixed surfaces, then shifted them a few fine offset 'clicks' up/down as needed to get them more blended again. Note that all the gizmo adjustments I did were with snap on - a lot of fine-tuning is possible, but this demonstrates that some very basic rule-of-thumb changes can already make a huge difference.
  • I also added a bit of camber to the wings (outer edge of the wing rotated one fine click, 5 degrees, up) - this helps with stability during flight and reentry.
  • The two circular intakes on the side stacks are relatively draggy and are not very heat resistant. I replaced them by a NCS + small nose cone.
  • With full tanks, there is way too much liquid fuel for a basic roundtrip to LKO and back. Jets use a fraction of the fuel units that rocket engines do - it pays to watch during a trial run how much your set of engines need to get to their maximum speed/altitude, and then keep your LF as close to that amount as possible, with a bit to spare for safety margin. All that LF is basically dead weight costing dV if it stays unused. So I replaced the engine nacelles by FL-T400 LFO tank. To restore air intake, I added an XM-G50 radial intake on top.
  • I added nose cones to the back of the Swivels and offset them forward. Besides making a cleaner visual for a spaceplane, it also plugs the open stack nodes and removes some more drag (a 'KSP physics' quirk).
  • I replaced all RCS thruster blocks by two 6-way balls of linear ports, one on the nose and one between the Swivels. This gives full RCS translation, and leaves roll to the reaction wheel. Additionally, the front ball affords the cockpit enough heat protection for LKO roundtrips.
  • The single rudder wasn't able to control sideslip, so I doubled the delta winglet, moving them back, down, and to the sides. I added deployment to the brake action group, so they function as airbrakes too.
  • After a few test flights I decided there was too much LFO for the swivels, so I replaced the Mk2 LFO fuselage by a second short cargo bay (assuming that you don't yet have the larger cargo bay unlocked). Without that surplus LFO, the plane now has a larger more useful cargo space, and it can carry more payload mass to orbit.
  • I could not see well enough into your cargo bay to replicate it, so I added a 1.25m reaction wheel (more efficient than the two small ones I can see), a 1.25m mono tank, and a 1.25m docking port to the front node of the bay. Radially attached to those I added batteries, solar panels, antenna, and lights. There was also room for some small radiators (attached to the crew cabin then offset into the bay) to help cool the cabin and cockpit a bit faster once in space. On the back node of the bay I added a Jr docking port and another light.
  • The cargo space was now large enough for an FL-T400 LFO tank with ports, so I added one and fully fueled it as test payload (2.3t).

 

The resulting build makes it to LKO with a respectable payload (refuel pod? station module? orbital telescope?), almost without need of manual inputs, and is fully operational once in orbit. It holds its angle of attack very well during reentry, transitions gracefully into a glide, and is easy to land softly. The landing gear springs may need a bit of tweaking - it does like to bounce up from the runway a bit.

Aside from the clearly larger wings and the side stack tops, I think this still retains most of your design/concept - let me know what you think. There's still some gains to be had from further tweaking, but as it is, I think it's already a very functional tech tier-6 spaceplane.

(P.S.: if you prefer I don't share the craft, just let me know and I will remove the KerbalX page. It's your concept, no hard feelings.)

Edited by swjr-swis
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9 hours ago, Doslidnyk said:

Hah those are some cool planes, and showing how it's done!!  After following suggestions, moving components around, there were definite improvements.  Not quite there; but much closer.  I am starting to think, this is becoming as much about stubbornly "solving" it than any major in-game gains this will achieve ;)  Test runs have either ended with fuel out at an impressive, but decidedly sub-orbital trajectory; or orbit was not quite there, but possibly within reach - yet resources were so low I thought nah.

 

BUT.  I went and installed Editor Extensions Redux (props to @linuxgurugamer for the flag-carrying and @AeroGav for the suggestion in your Mk2 guide thread).  I snapped my main rear-most wings and front canards to 2 degrees.  I don't know what the wings had before, but it was fine-rotation guess work, and I'd not applied it to the canards either.  When I replaced the wings I'd left off the two 4-way wing-tip RCS thrusters, so that was a test a few less drag-inducing parts I suppose.  But the little docking port's still there.

 

@Andetch You were right about the balance, all previous test runs were very much threatening to backflip.  I think that's improved now.

 

Here's what I ended up with - for the moment, at least.  That graph though....

vG91M37l.png

tAUcskgl.png

WBcglm4l.png

Nice graphical anomaly at launch.

It still has very high drag values, and AoA is often >4.5ish at the lowest, but I can't help but think that little bit of more-precisely-controlled incidence to both canards and wings made a huge difference.  Before AoA was quickly >6 at the lowest, and more when faster and higher.  I watched control surface authority limits too, and that seemed to also have a fairly large impact.

ZO7IAVFl.png

N1cXxwAl.png

VeQZBLkl.png

And I Jeb made it :D  to an orbit, at least.  He says thanks, I think.  I don't speak his language, but he looks rather chuffed.

I say many thanks, too, for the tips here and other threads, mods, tools, videos.  Now to uh, take it back down and see how it handles that..  Assuming it doesn't end with fire, I'll put RCS back and beyond that look at modifying payloads.  It's exciting.

Glad to see you're making progress.    

For incidence angle,  I'd go for 5 degrees rather than 2 -   5 is the optimum angle of attack for lift at supersonic & hypersonic speed, so that's what we care about.   Rather than fly the plane with SAS on Stability assist mode, you can then try flying with it set to Prograde Hold.   This will significantly reduce drag.  

Note, you've added incidence to main wing and the canards,  but not the strakes inbetween.   The strakes will therefore stall last, and being in front of CoM,  will keep making lift when everything else has quit,  and send you nosing up into a deep stall.     Remember kids,  stuff in front of CoM should have same or slightly more incidence than stuff behind it  .    If this makes her adopt too much of a nose up attitude in "hands off" flight,  move the wings back a bit !

What's your flight profile?    Top speed on the Panther will be in level flight at about 14km up.    You should be doing at least 750 before starting rocket,  though after 750m/s power falls away very fast.      If you can't keep your AoA down while doing that speed at that altitude, you deffo need more wing.  Ideally you should have enough wing to do that altitude on prograde , with only the lift from wing incidence.

Your screenshots are tiny but it looks like you were getting lift to drag ratio of about 1.6 to 1 in the middle picture.  That's horrible !     My "Stretch Ray" was getting  4.2 to 1 at 19km and 830m/s.   AoA is mostly to blame.

Can you put those solar panels in the cargo bay?   You're only going to need them once you're in space, keep em out of the wind till then.  Attach them to a cylindrical thingy within the bay, maybe your science junior.   Likewise, you could stick it on the side of the science junior within the bay.

Engine Nacelle intakes - minor thing, but it doesn't need that much intake area if you already got two circular intakes.   A single mk1 liquid fuel fuselage on the back of the main fuselage would hold just as much fuel for less drag.

MK1 rocket fuel fuselage short - behind the cargo bay.    Like i stressed in my space plane guide,  don't use mk2 parts unless you really need their unique capabilities.   An ft-400 tank holds the same amount of rocket fuel for about a third as much drag.

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On 6/24/2018 at 1:39 AM, Doslidnyk said:

I have Supersonic Flight researched, but not Advanced Aerodynamics.

I just now noticed I completely missed this part. This means you do not have the delta wing section unlocked yet, or the elevon-2/3. My apologies, that makes the rear section of the wings invalid.

Luckily, two small delta wings and a type C wing give us a composite delta wing too, and the elevon-1 can fulfill the task of the others. The Prototype 2B (link updated) should now only use parts from the tech nodes you have available.

It's a few more parts in total, and a tiny bit less efficient/rigid, but performance and handling is for all purposes identical to the 2A.

Spoiler

X1hPizi.png

2B: rear wing section remade with available parts.

 

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Hello again!  So, "Pre-Whiplash SSTO Spaceplanes: Possible?"  Yes, they are.  Possible for me?  Yes, now they are! :D

On 6/26/2018 at 11:19 AM, swjr-swis said:

I just now noticed I completely missed this part. This means you do not have the delta wing section unlocked yet, or the elevon-2/3. My apologies, that makes the rear section of the wings invalid.

Luckily, two small delta wings and a type C wing give us a composite delta wing too, and the elevon-1 can fulfill the task of the others. The Prototype 2B (link updated) should now only use parts from the tech nodes you have available.

It's a few more parts in total, and a tiny bit less efficient/rigid, but performance and handling is for all purposes identical to the 2A.

  Reveal hidden contents

X1hPizi.png

2B: rear wing section remade with available parts.

 

Very cool you tried to make the same plane - and you got it to work (albeit with the other aero parts) but points for trying! 

 

I've got something I can stop calling a prototype :)

It has more wing, yet I was able to keep the visual proportions and overall concept to what I was going for - though through a bit of a cheaty offset clipping which isn't quite so nice for the "achievement" factor - the second set of wings came after.  Maybe I'll try re-placing/re-ordering the parts and see if it still works.  I re-added forward strakes, and as well as the canards, with increased incidence compared to the main wings.  Swapped the nacelles for FL-T100s.  Swapped the nose cone/NCS adapter combo for a cone and a Mk1 fuel tank behind "economy".  I saw that the nacelles/ncs/cone did indeed weigh more, and carried less fuel than the cone/mk1!

It got to orbit far easier than every other iteration.  AoA was far more sensible.  Lift-drag ratio was better - though not as good as what you were talking about with your plane @AeroGav - so overall drag forces are still quite high.  But I've opted to leave some things on the exterior, so there's that.  I don't have to use afterburners to retain acceleration for the first ~5km altitude, if I keep a shallow pitch.  I got to ~750m/s without activating the Swivel, and didn't have a very hard time getting to ~15-16km (I'd let it go a bit before I noticed and lowered pitch to keep acceleration).  After I cut engines at around 75km apoapsis before circularising, I had 239 lf / 210 ox left, and after that seems a decent amount leftover, for that size craft, to do a bit more without a refuel operation.

I checked out KerbalX, and it's very cool.  Craft file here if anyone's interested to play around with it - interested to see what else could be done with it ;)

 

Whether it can carry much in the way of transferable cargo or fuel to something in orbit remains to be seen; at least whether it's more "efficient" than a pile of boosters.  But it seems more elegant and maybe more fun, though!  Also, I've learned kind of a lot of stuff.  Thanks a lot everyone who has given me tips and advice; it will probably help other people, too.

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Edited by Vegvisir
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@Vegvisir Not wanting to reinvent the wheel,  I took something based on your craft  to produce the next step - a Panther/NERV  SSTO.  

I kept the basic fuselage layout (small cargo bay, mk1 cockpit and crew cabin) , but added more wings since we need good lift/drag ratio in hypersonic flight if your propulsion is as weak and heavy as a nerv.

I'm quite pleased at how it ended up looking,   those mk2 parts are certainly pretty, and i don't normally go for modular wings (preferring fuel containing big S parts) but doing so gives much more control over how the craft looks.

By the time I added incidence, control surfaces, and tweaked wing locations for correct centre of litt it has lost some of its sleekness, but still looks better than what i normally make.   That's the upside to enforced low tech !

Fuel ends up in pods either side of the cargo bay,  which means no CG shifts as the fuel burns off.   That means an airplane that holds closer to prograde throughout the flight, which means less drag - as well as being nicer to fly.

Two Panther and Two Nervs.    I was going to  make it completely LF only,  but that means not using the oxidizer tankage of the mk2 adapters.

On Prograde hold mode, she does 0.65 deg AoA on Prograde hold, with no input from me.

Zz8YjJd.jpg

If you take SAS off and let aerodynamics do their thing,  the nose rises a little more - to 1.4 degrees

Wyd99Gl.png

Around 8 or 9 km, there isn't enough lit even at this angle to maintain our climb.     The inboard elevons are bound to action group 1, and push the nose down a couple of degrees when selected, which puts us in a low drag mode for crossing the sound barrier.  After crossing mach 1,  lift increases dramatically too,  and i'm using this action group intermittently to try keep us from bobbing over 14km when the jets start to loose power.

After porpoising up and down a few times ,  we eventually hit 750 m/s in level flight at 15km.  I start the rockets and cancel the nose down trim.    The oxidizer runs out about 1500 m/s.

dXSNYCK.jpg

Eventually,  after some imid course corrections and over corrections, we end up here - 

Plenty enough fuel to land and go back to Kerbin, though you need a horizontal landing vernier system for a really stylish rolling touchdown on the flats.   Could drive to several biomes this way, it doesn't use much fuel on the ground !

D2IcUGw.jpg

https://kerbalx.com/AeroGav/Krakenskimmer-Mandalay-class-SSTO  file here !

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4 minutes ago, AeroGav said:

@Vegvisir  Não querendo reinventar a roda, eu peguei algo baseado em sua arte para produzir o próximo passo - um Panther / NERV  SSTO .  

Mantive o layout básico da fuselagem (pequeno compartimento de carga, mk1 cockpit e cabine da tripulação), mas acrescentei mais asas, já que precisamos de uma boa relação de sustentação / arrasto em vôo hipersônico se sua propulsão for tão fraca e pesada quanto um nervo.

Estou muito contente com o resultado final, as partes do mk2 são certamente bonitas, e eu normalmente não gosto de asas modulares (prefiro combustível contendo grandes partes S), mas isso dá muito mais controle sobre o visual da nave.

Quando acrescentei a incidência, as superfícies de controle e os locais das asas ajustadas para o centro correto do litt, ele perdeu parte de sua suavidade, mas ainda parece melhor do que normalmente faço. Essa é a vantagem de baixa tecnologia forçada!

O combustível acaba em vagens de cada lado do compartimento de carga, o que significa que nenhum CG se desloca quando o combustível queima. Isso significa um avião que se aproxima do prograde durante todo o vôo, o que significa menos arrasto - além de ser mais agradável de voar.

Dois Pantera e Dois Nervos. Eu estava indo para torná-lo completamente LF apenas, mas isso significa não usar o tankage oxidante dos adaptadores mk2.

No modo Prosseguir espera, ela faz 0.65 deg AoA em Prograde hold, sem nenhuma entrada de mim.

Zz8YjJd.jpg

Se você tirar o SAS e deixar a aerodinâmica fazer as coisas, o nariz sobe um pouco mais - para 1,4 graus

Wyd99Gl.png

Cerca de 8 ou 9 km, não há iluminação suficiente, mesmo neste ângulo, para manter a nossa subida. Os elevadores internos estão ligados ao grupo de ação 1 e empurram o nariz para baixo alguns graus quando selecionados, o que nos coloca em um modo de baixo arrasto para cruzar a barreira do som. Depois de cruzar mach 1, o lift também aumenta drasticamente, e eu estou usando este grupo de ação de forma intermitente para tentar nos impedir de balançar mais de 14km quando os jatos começarem a perder potência.

Depois de subir e descer algumas vezes, chegamos a 750 m / s em vôo nivelado a 15 km. Eu começo os foguetes e anulo o nariz para baixo. O oxidante esgota cerca de 1500 m / s.

dXSNYCK.jpg

Eventualmente, depois de algumas correções e correções, acabamos aqui - 

Combustível suficiente para aterrissar e voltar para Kerbin, embora você precise de um sistema de vernier de aterrissagem horizontal para um pouso realmente elegante nos apartamentos. Poderia dirigir para vários biomas dessa forma, não usa muito combustível no solo!

D2IcUGw.jpg

https://kerbalx.com/AeroGav/Krakenskimmer-Mandalay-class- SSTO   file here!

For a more elegant landing as you said, you would have to use some mods, in that your craft would no longer be totally stock, and certainly would have to make changes so that the new weight of these new pieces does not affect the original structure.

If you want to change the ship for a more elegant landing I recommend using the Vtol system, or the classic kerbal Foundries 2 anti-gravity levitators are great, you would only need aerial brakes and parachutes to be able to brake at high speeds, but in low speeds air brakes solve there is only to turn off the anti-gravity system after lowering the landing gear. =)

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7 hours ago, AeroGav said:

@Vegvisir Not wanting to reinvent the wheel,  I took something based on your craft  to produce the next step - a Panther/NERV  SSTO.  

Zz8YjJd.jpg

Eventually,  after some imid course corrections and over corrections, we end up here - 

Plenty enough fuel to land and go back to Kerbin, though you need a horizontal landing vernier system for a really stylish rolling touchdown on the flats.   Could drive to several biomes this way, it doesn't use much fuel on the ground !

D2IcUGw.jpg

https://kerbalx.com/AeroGav/Krakenskimmer-Mandalay-class-SSTO  file here !

 

Wow, yeah!  That's awesome!  Definitely gonna download it and check it out.  I like the style of it, and if you got to Minmus and back in it, it's got function too!

 

Last night I took 3 Kerbals up in Tempest.  There wasn't very much fuel left, not enough to get to Mun orbit where there's a probe I'd like to take my scientist and engineer to meet.  So I tweaked a fuel transferring version by swapping the cabin and the cargo bay contents for two of the second-smallest LF tanks.  Got up to orbit easily, and after rendezvous managed to dock!  I've hardly ever docked so that was cool.  Used quite a bit of the monoprop in one to do that, and there could probably be a benefit to a couple more RCS thrusters.  But it totally worked, even if the two ships look quite a mess joined together!

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I since sent the refueler plane back down and landed at KSC.  Still didn't have as much fuel as I kinda wanted.  So built a prototype probe-controlled refueler and sent that up, and docked with the orbiting plane.  The plane then had around 1200m/s dV and I sent it off to Mun.  Deorbited my probe with RCS power and came down 24km from KSC - that in itself was pretty cool; still guessing and learning to control that.  I compared the launch cost and recovered funds of both my refueler-configured plane and the probe, the difference is pretty amazing.

 

Throughout building, flying and refueling this thing, I think I can say I've learned how to plane - a lot more than before - and was good docking practice.  I currently have only Jeb and Val as pilots and both are unavailable right now, and a contract I'd like to fulfill without waiting for Jeb.  So I've built a little barebones plane and sending it off with an Engineer.  With better aero design and giving it a go using trim controls, I can fly it.  Before was like, no pilot, no SAS, nope!

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