I Don't Get Spaceplanes

[Wanderfound]

I just find it impossible to skirt the atmosphere. I loose control every time or run out of fuel (through flight, not lack of).

Could be a ship design problem, could be a piloting problem. If you like, have a go with this: http://forum.kerbalspaceprogram.com/threads/89092-Kerbodyne-Scattershot-a-simple-and-easy-to-fly-beginner-s-SSTO-spaceplane

That plane can certainly get to orbit with ease (under FAR, anyway; haven't tested it with stock aero). I designed it specifically as an easy-to-fly trainer. Get to 20,000m as fast as possible, then level off and crank it up to Mach 4 while you slowly climb. By the time you hit 30,000m, you want your climb rate to be around 10m/s and your angle of attack as low as possible.

Shut off either the turbojet or the RAPIERs once the air supply gets low; don't let the RAPIERs switch to closed cycle yet (use action group 2 to shut them down if they do, action group 3 to switch modes). Keep the shut-down engines off until you can't accelerate or climb any more (should be somewhere a little over 30,000m/Mach 4.5), then pull the nose up to 45 degrees, switch the RAPIERs to closed cycle, activate all engines and go to space. Flick the RCS on if the handling gets squirrelly (worth doing in advance as a precaution just before you start the final oxidising burn) or if you need to recover from a mistake, but keep it off otherwise.

Your apoapsis should hit 70,000m with the tanks still half-full in less than a minute of oxidising burn if you're flying right.

[Yakuzi]

I just find it impossible to skirt the atmosphere. I loose control every time or run out of fuel (through flight, not lack of).

Any pics of your ship? Loosing control at high altitudes can be caused by various reasons... Is the pitch or the yaw uncontrolable? Pitch issues are most likely due to changes in your CoM as you burn fuel. If you have an multi jet-engine setup, yaw issues (or pitch depending on the jet engine placement) can be caused by partial loss of thrust in one engine due to low oxygen. Keep an eye on SAS yaw/pitch/roll correction and throttle down (or switch engines) as soon as you see incremental changes.

Edited August 4, 2014 by Yakuzi

[Hodo]

plane in KSP is lackluster now.

the lack of a stock cargo bay make the whole point of flying a plane meaningless, and how weak the stock control surfaces are forces you to install B9

but the problem of B9 is, the maker hasnt updated it since 0.23.

you have to find the communtiy fixes for the .dll youself

They are weak? I use them on some of my smaller SSTOs and they work fine. Not sure what you are talking about.

[Alshain]

the lack of a stock cargo bay make the whole point of flying a plane meaningless

I could not disagree with this more. Planes are meaningless as opposed to flying digital pixels shaped like a Rocket? Really, the entire game is meaningless along with every other game ever made, computer, tabletop, or otherwise. It's entertainment, why do the planes have to have a functional purpose when they are simply fun to fly?

[Subasean]

Be very aware of CoM shifts at hypersonic speeds. I have the payware SR-71 for FSX and like the real aircraft Angle of Attack past 7 degrees at Mach 3 is a VERY sketchy proposition, and fuel balance is completely manual on that one. I play exclusively with FAR and my SSTO spaceplanes exhibit the same behavior. For giggles I made basically an "SR-71+" as an SSTO, two turbojets in the wings and an aerospike in the tail (no RAPIERs for this guy!) and once I engaged the aerospke the fuel consumption shifted my CoM so violently, the tail sank, had a left engine unstart followed very rapidly by the starboard wing shearing off.

As suggested before, make every effort to place fuel tanks where, empty or dry, the Center of Mass doesn't shift much, if at all. TAC fuel balancer can be a huge help, but it sometimes takes some experimentation to memorize which fuel tank is where and when to shift things around. (On the other hand, uber-nerd that I am, I do enjoy writing down basic flight manuals for my planes and doing test flights to find their absolute flight envelopes so I don't forget. None of this is necessary, just makes me feel like I'm practising for when I get my degree. =P)

[Heagar]

Planes in general doesn't act like planes in a flight simulator, because KSP was build for rockets. The wings where introduced, when SQUAD realized that a mod (the same modders as B9) was very popular.

Then the sudden change in the athmosphere layers (it's only slightly corrected with NEAR or FAR) can cause troubles, witch you can overcome e.g. by airhooging.

If you need some inpirations for spaceplanes (what they can archieve and how to set up) a few links:

• The K Prize - 100% reusable spaceplane to orbit and back
  
• Better SSTO Spaceplane Challenge (0.23.5+0.24) Extended
  
• An Affordable Space Program: making the reusable spacecraft pay off.
  
• BSC: Aeris 4a
  
• 
  

What you can say for sure is the following:

The very first spaceplane is hard to build, but when it's functional, it's a huge "whow"-effect.

Then you have to finetune your designs. Because:

• At most bigger spaceplanes the CoW will change
  
  • pumping the fuel arround helps or
    
  • maybe you want to install TAC fuel balancer.

  [*]The plane is very twichy

  • you can - by pressing the "caps-lock" key - activate the "fine controls".

  [*]if your plane repeatedly trys e.g to pitch up or down

  • you can use the "Alt" + "WASDQE" keys to trim your plane. But i suggest using it only for the pitch, since there is no zeroing key if needed.

Aaaand most of all:

Because you are playing an simulator (FlightGear, maybe FSX too?) i guess you have an flightstick, am i right?

In that case you can set it up under Settings/Input/Staging UI. There you find pitch, roll, yaw and throttle. (Worked fine for me with a HOTAS warthog & CH pro pedals). I will be that you have to pull down the sensitivity a lot and to increase the deadzone a little.

Under the Misc-Tab you will find the camera controls, witch is nice to have on the flightstick while flying IVA.

[StevenJ]

I fly spaceplanes almost exclusively, and I don't use B9 (just downloaded Spaceplane Plus today, but I don't expect to use it much; sure, they're pretty, but all your planes end up looking kinda the same if you use those parts).

While a stock cargo bay would certainly be a sensible addition, it isn't that hard to build your own from parts. And the standard control surfaces work just fine. If you're having trouble controlling your plane or the control surfaces are tearing off, the problem is in the design, not the parts.

Mod-kit planes are like putting together a Lego model according to the instructions. Stock part planes are like being given a bucket full of random blocks and making something new and cool.

Agree with Lego part, disagree with the rest. I've managed to get very creative with B9 parts and procedural wings to create truly unique designs. I tried space plane plus, I like the effort but was disappointed in the parts. I only keep the ram jet intake and radial intake from that mod in my install. To the original post, space planes, though significantly harder to design and fly, are for those who want re-usability in their space craft. Also because they are planes, you can control your decent and land back at the runway with practice. I build rockets and space planes with a focus on space planes because they are more inexpensive in the long run due to the fact you recover the craft minus fuel. They take a while to learn and fly, especially with FAR and DRE installed like I do , but it's worth it in the long run.

http://cloud-4.steampowered.com/ugc/563267371926203681/2FEEA1F136D8818B0534D0CC68FF970320EBE48E/

[Wanderfound]

Agree with Lego part, disagree with the rest.

I think I did get carried away by rhetoric a touch. It's certainly possible to come up with creative designs using B9 or Spaceplane Plus parts; they just don't force creativity on you the way that the stock parts tend to.

I think the Lego analogy still stands, but with the added caveat that you're free to ignore the instruction booklet no matter which parts you're using.

[StevenJ]

I think I did get carried away by rhetoric a touch. It's certainly possible to come up with creative designs using B9 or Spaceplane Plus parts; they just don't force creativity on you the way that the stock parts tend to.

I think the Lego analogy still stands, but with the added caveat that you're free to ignore the instruction booklet no matter which parts you're using.

I will definitely add the stock plane parts are far too limiting. Procedural wings alone helps a ton not only saving on part count but also giving you the exact wing shape you want.

[DocMoriarty]

Space planes aren't that hard to build when you know what you are doing. If you do the alignments of CoM, CoL and CoT right and keep a few other things like correct position of rear gears and SAS configuration in mind they fly like a charm from first drop of fuel used to last and be your best friends, especially in career mode.

I was lately working on a little documentation on how to create and operate space planes in stock KSP, especially for 0.24 and career mode, with lots of images, how to's and checklists. It's nearly finished now and a preliminary version as PDF is available here:

http://www.docmoriarty.com/ksp/mods/KSP%20Space%20Plane%20Construction%20and%20Operation.pdf

Edited August 9, 2014 by DocMoriarty

[CatastrophicFailure]

Y'know, I've tried and tried to like space planes, but I just don't. Stock or modded, I can build them and make them work, but they just bloody take forEVer! In the time it takes to launch and recover a single space plane I can launch a simple multimodule space station with conventional rockets. And they're just so darned... refined. There's just a certain visceral satisfaction to seeing a Brazilian tons of highly volatile rocket fuel transform its self into energy and FIRE! as quickly and dangerously as possible. And when things go wrong with rockets there's such a delightful finality to it... no sense wasting effort trying to recover the unrecoverable... just GTFO... using moar rockets!

And where's the love for reusable and SSTO rockets? I'd dare say an SSTO (vertical) rocket is even more of a challenge than a spaceplane, and with the advent of funds (and parts with KCT) recovery with .24 spaceplanes no longer have much advantage over multistage fully recoverable rockets, ala the SpaceX Falcon.

[cantab]

[*]you can use the "Alt" + "WASDQE" keys to trim your plane. But i suggest using it only for the pitch, since there is no zeroing key if needed.

Yes there is - Alt + X.

And where's the love for reusable and SSTO rockets? I'd dare say an SSTO (vertical) rocket is even more of a challenge than a spaceplane

Not really. Even the pre-ARM stock rocket engines were quite capable of it. Jet-boosted rockets, staged on not, are perhaps more challenging though, with the unusual ascent profiles required for lowest fuel use.

[CatastrophicFailure]

Not really. Even the pre-ARM stock rocket engines were quite capable of it. Jet-boosted rockets, staged on not, are perhaps more challenging though, with the unusual ascent profiles required for lowest fuel use.

Er, yes that's what I was referring to.

[SRV Ron]

Will have to do a daylight flight to demo that this ship can reach 2400 m/sec at about 35,000 meters so that only a very short burn is needed to circularize the payload into orbit. The fins act to stabilize lift at high altitude for the speed run to space.

The jet section is recoverable but unflyable once the payload is staged.

[Wanderfound]

Will have to do a daylight flight to demo that this ship can reach 2400 m/sec at about 35,000 meters so that only a very short burn is needed to circularize the payload into orbit. The fins act to stabilize lift at high altitude for the speed run to space.

http://i.imgur.com/oOkte8s.jpg

The jet section is recoverable but unflyable once the payload is staged.

I've been working on something similar, albeit on a slightly larger scale...

It's pricey, but it should be 100% recoverable; it parachutes onto landing legs. As you can see in the second shot, the Rockomax 64 is the payload, not the lifter fuel. Whack the nose to 30° just after takeoff, wind it up to Mach 4.5 by 30,000m, then flick on the Vernors to hold it stable while the 20 RAPIERs take you to space.

It's quite nippy. Surprisingly manoeuvrable too, so long as you keep the Vernors on. Bit noisy, though.

Edited August 10, 2014 by Wanderfound

[jaddbo]

I also have trouble withe spaceplanes and SSTO's. I started a thread about that

tread:SSTO question

[Wanderfound]

I also have trouble withe spaceplanes and SSTO's. I started a thread about that

tread:SSTO question

And I had a few things to say there, too.

If you're still having trouble, I'd suggest using the example plane I linked to over there (Kerbodyne Scattershot) and flying it to orbit following the hints I gave regarding ascent path. Once you get back down, go into the SPH and tear the plane to pieces so you can see how it was put together, then try and build your own one.

[StevenJ]

Will have to do a daylight flight to demo that this ship can reach 2400 m/sec at about 35,000 meters so that only a very short burn is needed to circularize the payload into orbit. The fins act to stabilize lift at high altitude for the speed run to space.

http://i.imgur.com/oOkte8s.jpg

The jet section is recoverable but unflyable once the payload is staged.

Is that with jets only? While I respect your enthusiasm I can't wait for the day that Squad corrects the performance curves for turbines so they operate in a realistic manner. No turbine in the world could do that kind of speed with out melting it's own blades, much less past mach 3.5 without doing that. I can't wait until jet engine over heat and melt downs are properly implemented to end air hogging as it's soo unrealistic it's mind-boggling. That and a complete redo of the atmospheric modeling, but thankfully a lot of this has been covered through mods. Sorry I shouldn't tell others how to play the game, but to see people getting absolutely ridiculous speeds out of a turbine, without even the thought of a precooler of some sort, is just mind blowing to me. You know why those Skylon SABRE engines in the real project require those huge powerful precoolers? They need them because the air breathing components, like the turbine used to force air into the rocket motor, would literately melt without them. Sorry to rant, it's not you personally just more of a general thing. I wish the game wasn't so cartoonish in these aspects. Like people building rockets without nose cones or fairings, yet still manage to send ridiculously non-aerodynamic payloads into orbit. Just like people send Kerbals on multi year missions without even the slightest provisions for oxygen recycling, water, or food. I guess some day there won't be a need for those 'certain' mods. No offense to any vanilla players of course.

[Wanderfound]

Is that with jets only? While I respect your enthusiasm I can't wait for the day that Squad corrects the performance curves for turbines so they operate in a realistic manner. No turbine in the world could do that kind of speed with out melting it's own blades, much less past mach 3.5 without doing that. I can't wait until jet engine over heat and melt downs are properly implemented to end air hogging as it's soo unrealistic it's mind-boggling. That and a complete redo of the atmospheric modeling, but thankfully a lot of this has been covered through mods. Sorry I shouldn't tell others how to play the game, but to see people getting absolutely ridiculous speeds out of a turbine, without even the thought of a precooler of some sort, is just mind blowing to me. You know why those Skylon SABRE engines in the real project require those huge powerful precoolers? They need them because the air breathing components, like the turbine used to force air into the rocket motor, would literately melt without them. Sorry to rant, it's not you personally just more of a general thing. I wish the game wasn't so cartoonish in these aspects. Like people building rockets without nose cones or fairings, yet still manage to send ridiculously non-aerodynamic payloads into orbit. Just like people send Kerbals on multi year missions without even the slightest provisions for oxygen recycling, water, or food. I guess some day there won't be a need for those 'certain' mods. No offense to any vanilla players of course.

As well as fixing the aero, the latest version of FAR nerfed the power output of the air breathing engines by 50% and added some reality to their altitude/speed thrust curves. You can still get to Mach 5 on a single non-airhogging turbojet if you do it right. There ain't a lot of drag at 30,000m.

[StevenJ]

As well as fixing the aero, the latest version of FAR nerfed the power output of the air breathing engines by 50% and added some reality to their altitude/speed thrust curves. You can still get to Mach 5 on a single non-airhogging turbojet if you do it right. There ain't a lot of drag at 30,000m.

Yes i am well aware of the nerf as i'm running the latest version of FAR. It depends on the engine. The SABRE / Rapier engine should get to mach 4 or 5 in atmosphered but normal turbines shouldn't. I'll have to try it again with more intakes to see if the can get something like the stock turbo jet with far or the B9 turbo jet to mach 4. I got the B9 turbo jet to mach 3.5 or so, a bit more than realistic, with .4 intake volume. I hadn't yet unlocked more advanced intakes at that point in the tech tree.

[Wanderfound]

Yes i am well aware of the nerf as i'm running the latest version of FAR. It depends on the engine. The SABRE / Rapier engine should get to mach 4 or 5 in atmosphered but normal turbines shouldn't. I'll have to try it again with more intakes to see if the can get something like the stock turbo jet with far or the B9 turbo jet to mach 4. I got the B9 turbo jet to mach 3.5 or so, a bit more than realistic, with .4 intake volume. I hadn't yet unlocked more advanced intakes at that point in the tech tree.

Well, keep in mind that the turbojet is supposed to be cutting-edge and top-of-the-line. Not just an SR-71, but an SR-71 equivalent that was designed in the 21st century rather than the 1960's. And, of course, it's a fun game about silly little dudes with big green heads. I'm not too bothered by the occasional bit of less than perfect realism.

Extreme air-breathing speed and altitude is more about piloting and aerodynamics than air-hogging. I generally don't use more than one nacelle/ramscoop combo per engine. If you take the time, you can get a basic minimalist plane (one turbojet, two delta wings, two ramscoops, a tailfin, a cockpit and a type 1 fuselage) up to ridiculous height and speed (>30,000m, >2,000m/s).

Slow ascent, minimal angle of attack, shut down all but one engine, throttle back as necessary and fly halfway around Kerbin while very slowly accelerating. You can kinda skip across the lower atmosphere if you do it right, with the engine constantly fluttering between flameout and just-barely-running.

[sedativechunk]

This is an interesting discussion. In terms of anything like a plane, I recently just started using the Tiberdyne Space Shuttle mod. It has some minor issues in 0.24 but works fairly well still. Like others here said, spaceplanes (or shuttles) are extremely efficient for transporting cargo and things into space. The shuttle works exceptionally well for transporting cargo and with contract mode, recovering the entire craft saves lots of credit. They are also good for creating significantly less space debris, especially when dealing with creating a space station.

But there's another side of the shuttle argument, and it's similar to reality; shuttles are clunky and dangerous to fly. Versus a classic teardrop capsule, they just aren't as friendly for recovering humans/kerbals.Also I find the game more time consuming/hassle trying to bring back/land shuttles instead of just dumping a tear drop capsule into the ocean.

[Mesons]

Extreme air-breathing speed and altitude is more about piloting and aerodynamics than air-hogging. I generally don't use more than one nacelle/ramscoop combo per engine. If you take the time, you can get a basic minimalist plane (one turbojet, two delta wings, two ramscoops, a tailfin, a cockpit and a type 1 fuselage) up to ridiculous height and speed (>30,000m, >2,000m/s).

Slow ascent, minimal angle of attack, shut down all but one engine, throttle back as necessary and fly halfway around Kerbin while very slowly accelerating. You can kinda skip across the lower atmosphere if you do it right, with the engine constantly fluttering between flameout and just-barely-running.

Even though, as many others have said in this thread, this process can be time-consuming and ultimately not as fun to pilot as more rocket launches and rendezvous in the same time frame, I find it gripping and fulfilling to feather the controls and gently ease simple planes like that into near-orbit. It's almost separate from the rest of the gameplay for me, as I care much more about flying my planes than engineering them to be capable of land-and-return on other bodies or even designing them to have enough fuel to do more than orbit, rendezvous, and fly home to KSC.

[Moar Boosters]

This is an interesting discussion. In terms of anything like a plane, I recently just started using the Tiberdyne Space Shuttle mod. It has some minor issues in 0.24 but works fairly well still. Like others here said, spaceplanes (or shuttles) are extremely efficient for transporting cargo and things into space. The shuttle works exceptionally well for transporting cargo and with contract mode, recovering the entire craft saves lots of credit. They are also good for creating significantly less space debris, especially when dealing with creating a space station.

But there's another side of the shuttle argument, and it's similar to reality; shuttles are clunky and dangerous to fly. Versus a classic teardrop capsule, they just aren't as friendly for recovering humans/kerbals.Also I find the game more time consuming/hassle trying to bring back/land shuttles instead of just dumping a tear drop capsule into the ocean.

Recovering a shuttle isn't too difficult. It takes a bit of time to learn to fly/glide a shuttle back to KSC but once you've acquired the skill it's much more fun than dropping a capsule in the ocean.

Spaceplanes cover a wide variety of vehicles. Whilst I'm not against skimming the atmosphere and building my own cargo bays, I wanted something easy to use for my career mode.

This is what I came up with. It's empty here, but has enough power to delivery just over 3 orange tanks to orbit. There's no fancy cargo bays, the payload is mounted straight on the top. It'll take any size or shape payload as long as the weight is centered.

Obviously the first stage isn't reusable...... it's 24 solid boosters stuck to a decoupler and held together with struts and duct tape. This is enough to get it to around 10,000m and 300m/s, then the reusable second stage takes over and is enough to bring the payload to orbit, and then de-orbit itself. For the journey back to KSC it's got 4 basic jet engines because I'm not great at aiming re-entries and usually have to do a bit of flying to get to the runway.

It flies very nicely when returning to KSC. I think people spend too long trying to lift fuel laden behemoths off the runway, they forget how few wings you need to allow empty fuel tanks to fly.

[Technical Ben]

Thanks peeps! I've got a space plane working finally. I simplified it and stuck to just a Rapeir Engine. I fluffed the landing, as I thought it would be a good idea to come in a ballistic trajectory to "save time" and pull up the last second... then I span it.

But other than piloting error, it's all go now.