Super-Heavy VTOL Issues

[TelluriumCrystal]

Hi,

This is my first attempt at making a VTOL, and needless to say it is probably one of the more ambitious ones. However, due to my lack of experience, I am having issues getting stable VTOL flight. I should point out that this aircraft is huge, and I need around 8 basic jet engines to get it off the ground. However once it leaves the ground, it tends to tilt over to one side, causing me to loose control and forcing me to abort the flight. I suspect this is due to my engine placement, or lack of RCS, but instead of spending 4 hours on it, I figured I'd toss it out there and let the community explain to me the proper way to do this.

Craft File: MediaFire

Images:

Our brave test pilots.

Engines powering up. They have to reach above ~80% maximum thrust to achieve lift.

Liftoff!

This is where it all goes wrong...

Continuing to loose control whilst all the engines overheat.

Loss of control – aborting test.

Don't worry, that's supposed to happen.

The remnants... Good thing we have an unlimited budget!

Quote to justify my laziness:

A smart man makes a mistake, learns from it, and never makes that mistake again. But a wise man finds a smart man and learns from him how to avoid the mistake altogether.

Edited May 16, 2013 by Thrfoot

[K^2]

There are a number of issues with VTOL. Biggest one is that the vectoring on engines becomes less and less efficient as the center of thrust is moved higher up towards center of gravity. If center of thrusts ends up above, you actually get engines actively trying to flip the craft over. So first thing is that if there is room at all, move the lifter jets down.

Second issue is that gimballing initiates when you fire a stage. If you just activate the engines via action groups, you get no gimball control. So fire all of your engines in one stage, then shut down these you don't need with action groups. When you re-activate these with action groups, they'll work as supposed to.

Finally, as fuel is used up, center of mass shifts. Your VTOL might start out perfectly balanced and hover steady, and then a few seconds later start turning over. Before you can properly react, the thing is flipping over. You have to make sure that fuel is being used up symmetrically around center of mass. Not an easy task, but that's the only way you'll get a good VTOL.

P.S. Which mod is that cockpit from?

[DoggyGuy]

I havent been able to make a regular vtol

do you have any tips for me?

[TelluriumCrystal]

There are a number of issues with VTOL. Biggest one is that the vectoring on engines becomes less and less efficient as the center of thrust is moved higher up towards center of gravity. If center of thrusts ends up above, you actually get engines actively trying to flip the craft over. So first thing is that if there is room at all, move the lifter jets down.

Second issue is that gimballing initiates when you fire a stage. If you just activate the engines via action groups, you get no gimball control. So fire all of your engines in one stage, then shut down these you don't need with action groups. When you re-activate these with action groups, they'll work as supposed to.

Finally, as fuel is used up, center of mass shifts. Your VTOL might start out perfectly balanced and hover steady, and then a few seconds later start turning over. Before you can properly react, the thing is flipping over. You have to make sure that fuel is being used up symmetrically around center of mass. Not an easy task, but that's the only way you'll get a good VTOL.

P.S. Which mod is that cockpit from?

1. I'll see what I can do (have work to do right now, will try it in a few hours)

2. Thanks for that, I was wondering why they weren't gimbaling

3. The design won't allow me to do that easily. I may just end up re-distributing fuel when I get close to the LZ (this thing holds enough fuel to circumnavigate Kerbin)

Most of these parts are from bac9's wonderful B9 Aerospace Pack.

[GROOV3ST3R]

I think you should try the Falcon II VTOL Engine and use either more RCS thrusters or modify the linear ports to run on jet fuel and exert more thrust. I find flipping of craft to be a common problem for me since my COG is usually vertically lined up with the centre of thrust.

You can always add action groups that activate the engines AND gimballs at the same time - that might help - as will putting everything in a single stage.

Maybe you should try spreading the engines out a little so they aren't all squashed up in the centre of the craft - it's like balancing a plate on a stick or on a pillar. I don't think it will, or it shouldn't make any real difference but you never know, it might make it more stable in some way.

[K^2]

Maybe you should try spreading the engines out a little so they aren't all squashed up in the centre of the craft - it's like balancing a plate on a stick or on a pillar. I don't think it will, or it shouldn't make any real difference but you never know, it might make it more stable in some way.

That doesn't really make a difference. Logic is similar to pendulum fallacy. Now, if control systems varied thrust of individual engines to maintain balance, then spreading engines out would help.

[DocSnuggles]

The Plane looks a bit like the Nazis won WW2 and they are now building JU52 style space planes .... but i like it.

The Problem about big VTOL planes is that the thrust vector of the enginges don´t have the impact on the controls as they have on small VTOL. Another point is that the torque, the command modules provide, does not scale with your plane size. You can add some hidden command modules in order to get more force on your controls. This could be enough to keep your plane in air but it isn´t that big effect and it can´t compensate a defective design.

I also like to angle the engines counterwhise for some degrees so that some % of the thrust is directed to the front and to the back. If the Plane starts to turn forward for example, the front engines provide more thrust in direction to the ground. It helps to lift the front up and get back control of the plane. The engines at the backside lose downforce what´s also helping to get back in position. Negative aspect of this placement is that the backside engines provide thrust in forward direction so that the plane is starting to move forward ....but its better than losing total control. It´s also clear that some thrust is wasted by placing the engines not directly in direction of the ground.

This is a vid to show what i am talking about > http://youtu.be/nNZnQDAtSiA

To stop the roll of your craft you could do the same by directing the engines to the left and right but in this case it could be more efficient to work with adding some comand pods (unmaned) because they provide some good roll force.

One last point. Your pictures show the plane turning backwards. If you cannot balance the plane perfectly, try to tune it in that way that it´s turning forward. The aerodynamic surfaces of the game like planes flying in the right direction and it helps getting back control .

[bsalis]

That is very ambitious.

Is the wet and dry CoM in the same place?

[TelluriumCrystal]

I think you should try the Falcon II VTOL Engine and use either more RCS thrusters or modify the linear ports to run on jet fuel and exert more thrust. I find flipping of craft to be a common problem for me since my COG is usually vertically lined up with the centre of thrust.

You can always add action groups that activate the engines AND gimballs at the same time - that might help - as will putting everything in a single stage.

Maybe you should try spreading the engines out a little so they aren't all squashed up in the centre of the craft - it's like balancing a plate on a stick or on a pillar. I don't think it will, or it shouldn't make any real difference but you never know, it might make it more stable in some way.

1. Falcon II VTOL engines are really only meant for small craft and I would have trouble integrating them into this plane. Interesting idea though...

2. I might consider making some liquid fuel RCS ports. Thats actually a really cool idea!

3. Already done (well, going to be done)

4. But they look so cool grouped together...

The Plane looks a bit like the Nazis won WW2 and they are now building JU52 style space planes .... but i like it.

The Problem about big VTOL planes is that the thrust vector of the enginges don´t have the impact on the controls as they have on small VTOL. Another point is that the torque, the command modules provide, does not scale with your plane size. You can add some hidden command modules in order to get more force on your controls. This could be enough to keep your plane in air but it isn´t that big effect and it can´t compensate a defective design.

I also like to angle the engines counterwhise for some degrees so that some % of the thrust is directed to the front and to the back. If the Plane starts to turn forward for example, the front engines provide more thrust in direction to the ground. It helps to lift the front up and get back control of the plane. The engines at the backside lose downforce what´s also helping to get back in position. Negative aspect of this placement is that the backside engines provide thrust in forward direction so that the plane is starting to move forward ....but its better than losing total control. It´s also clear that some thrust is wasted by placing the engines not directly in direction of the ground.

This is a vid to show what i am talking about > http://youtu.be/nNZnQDAtSiA

To stop the roll of your craft you could do the same by directing the engines to the left and right but in this case it could be more efficient to work with adding some comand pods (unmaned) because they provide some good roll force.

One last point. Your pictures show the plane turning backwards. If you cannot balance the plane perfectly, try to tune it in that way that it´s turning forward. The aerodynamic surfaces of the game like planes flying in the right direction and it helps getting back control .

1. Yes, I knew controlling this would be a challenge from the start.

2. Interesting idea. I'll have to watch that video when I get the chance.

3. I'd really like to avoid adding command pods, as that would look funny. I'm hoping that the gimbal will be enough.

That is very ambitious.

Is the wet and dry CoM in the same place?

No idea... This thing has a LOT of fuel so I'd rather not spend 4 hours emptying the thing to find out. But chances are they aren't. I am planning to compensate for this by manually re-distributing fuel to balance it out before entering VTOL mode.

[GROOV3ST3R]

You know what you could try?

go to part.cfg and increase the gimball rating from 1 to 20 or more - just not more than 50.

With those particular engines, they look like they were meant to gimball that far and you get a lot more control over pitch movement. It doesn't help much for the yaw and roll though.

And to change RCS into ''jet thrusters'' all you need to do is copy the ISP curve over from the jet engine to the RCS thruster, increase output thrust SLIGHTLY (say that it is powered by the jet in your craft for example? It's not completely without reason ) and change the fuel from MonoPropellant to LiquidFuel. I did that and they work - although they might still work in space and that isn't ideal.

Still, play about with cfg files, if you back everything up, you can't go far wrong

On the side:

You need to make absolutely sure that the centre of gravity is lined up with the axis of the craft - i.e. all parts are symmetric and you don't have any parts that give the plane a tendency to veer off either side.

Also, when your craft is starting to lift off, throttle back. It needs more than 80% throttle but not 100% Often I had a similar problem with my VTOL planes - given too much thrust magnifies any stability issues and throws the plane out of balance. Try to start with throttle at 85%, see if you achieve lift-off, and if you do, throttle down a touch to stop or slow the vertical speed and hover a few meters above the ground - eventually you will learn to predict and counteract the movements and keep a stable-ish hover.

Last point I wanted to make is that pretty much every vtol I ever made has a tendency to sway out of control if it's completely stationary. I do my best to line all the centers up, I even fine-tune the balance with landing gear and batteries but it can be hard keeping a craft in a stable hover over a fixed position. If you can try to inch forwards at 3-5m/s and see if the craft is any more manageable then. Avionics package helps too as it will actively try to negate yaw and roll whilst still giving you control over the craft in all axes and directions. This is why I prefer it on planes rather than ASAS.

Drop a craft file in the original post and I will have a go with that plane to see if I can make it behave

[TelluriumCrystal]

Drop a craft file in the original post and I will have a go with that plane to see if I can make it behave

Ok, should be up now. You'll need Bac9's B9 Aerospace mod in order to load the file.

[erbmur]

Hey there!

I only just managed to build a decent sized functioning VTOL. Nothing as large as that, but big enough. Here are the pointers that I found to be the most useful:

1) The two mods that I believe to be invaluable for the proper creation and function of Vtols are http://kerbalspaceprogram.com/surface-mounted-counterweights/ ( to properly balance the craft)& http://kerbalspaceprogram.com/tac-fuel-balancer-v1-0/ ( to allow the balance to remain during flight)

2) Build your craft to look awesome!!! However, ensure that the fuel tanks symmetrical along the central axis of the craft.

3) Activate the center of mass view of the aircraft, and using the counterweights, position them in such a way that the center of mass of the aircraft falls within the center of all the fuel tanks, so if the fuel where to drain evenly throughout the craft, the center of mass would not shift.

4) With the center of mass positioned, active the center of thrust view and position your VTOL engines so that the center of thrust basses directly through the center of mass.

5) Make sure you have the TAC fuel balancer eithere attached to your vessel, or the module is hardcoded into the cfg file (my prefered method so every craft has it by default, also reduces the parts count)

6) role out onto the runway, but before activating your engines, open the fuel balancer GUI and make sure that it is set to balance the fuel (and oxidiser if applicable) to ensure that the center of mass of the craft remains in the same position. Otherwise the fuel will drain from one tank before the other, throwing off the center of mass and causing the craft to pitch one way or the other before crashing.

7) You should be good to go. Fire up your engines and away you go!

If I knew how to upload images i'de put one up of a VTOL to the mun I made, but I have no idea how to do so!

I've also downloaded your craft file, ill see if i can tinker it and send it back

Hope this helps!

[TelluriumCrystal]

Hey there!

I only just managed to build a decent sized functioning VTOL. Nothing as large as that, but big enough. Here are the pointers that I found to be the most useful:

1) The two mods that I believe to be invaluable for the proper creation and function of Vtols are http://kerbalspaceprogram.com/surface-mounted-counterweights/ ( to properly balance the craft)& http://kerbalspaceprogram.com/tac-fuel-balancer-v1-0/ ( to allow the balance to remain during flight)

2) Build your craft to look awesome!!! However, ensure that the fuel tanks symmetrical along the central axis of the craft.

3) Activate the center of mass view of the aircraft, and using the counterweights, position them in such a way that the center of mass of the aircraft falls within the center of all the fuel tanks, so if the fuel where to drain evenly throughout the craft, the center of mass would not shift.

4) With the center of mass positioned, active the center of thrust view and position your VTOL engines so that the center of thrust basses directly through the center of mass.

5) Make sure you have the TAC fuel balancer eithere attached to your vessel, or the module is hardcoded into the cfg file (my prefered method so every craft has it by default, also reduces the parts count)

6) role out onto the runway, but before activating your engines, open the fuel balancer GUI and make sure that it is set to balance the fuel (and oxidiser if applicable) to ensure that the center of mass of the craft remains in the same position. Otherwise the fuel will drain from one tank before the other, throwing off the center of mass and causing the craft to pitch one way or the other before crashing.

7) You should be good to go. Fire up your engines and away you go!

If I knew how to upload images i'de put one up of a VTOL to the mun I made, but I have no idea how to do so!

I've also downloaded your craft file, ill see if i can tinker it and send it back

Hope this helps!

1. I'll consider the counterweights, but thanks for pointing out that fuel balancing mod! I was literally about to go ask for one in the modding suggestion thread!

2. They're more or less symmetrical, but there might be some imbalances. I really can't say until I test it with a low fuel load.

3-4. Pretty much already doing this.

5. Yes, I will probably hard-code it into all my cockpits

6-7. An issue I was aware of but had no way to combat until now. Hopefully this mod will help.

As far as my own progress goes, I have gotten the VTOL engines more or less balanced now, but for some reason the spaceplane begins to have serious stability issues once I get over 25m above the ground. It literally starts yawing uncontrollably. This might be due to control surfaces messing with the aerodynamics of the vehicle – are there any mods that make control surfaces toggle-able?

On a slightly more successful note, regular flying is nearly perfectly balanced. This thing is really easy to fly and land manually (just don't try to glide with it, it's too heavy and needs thrust to maintain a low vertical speed).

Edited May 16, 2013 by Thrfoot

[erbmur]

On a slightly more successful note, regular flying is nearly perfectly balanced. This thing is really easy to fly and land manually (just don't try to glide with it, it's too heavy and needs thrust to maintain a low vertical speed).

I have the FAR mod installed and I can't even get this thing off the ground let alone land!

I know there is a mod that disables control surfaces once you leave the atmosphere, but non that do it inside i'm afraid.

Looking at the images you have on the first page, it looks the plane pitches up after takeoff. Having a look at the center of gravity, It looks as though it is too far forward with regards to the center of gravity of the fuel tanks alone. If you can align it with the center of the fuel tanks, i guess using the counterweights, then align the center of vertical thrust to the new COG you should be fine.

Keeping the fuel drain balanced will ensure the COG remains constant rather then slowly moving back as the fuel from the front tank is drained first.

I use the balancer on all my planes, makes keeping the COG and the COL balanced a whole lot easier during the entirety of the flight. (I guess studying aerospace engineering for 4 years also helps!)

[GROOV3ST3R]

I downloaded the pack prior to you posting the link Just gonna drop in and try it out Watch this space.

Also, you can just Edit the post and manage Attachments - this lets you add a craft file to the post without having to upload it anywhere else

[TelluriumCrystal]

Uploading a new (and better balanced) craft file. This is the one that flies well in regular flight. It also looks cooler, has more RCS, and has the VTOL engines correctly balanced. Please re-download if you have already downloaded a copy!

Note that the main issue with this version is loss of control after about 6 seconds of stable, sustained VTOL flight.

Edited May 16, 2013 by Thrfoot

[GROOV3ST3R]

Uploading a new (and better balanced) craft file. This is the one that flies well in regular flight. It also looks cooler, has more RCS, and has the VTOL engines correctly balanced. Please re-download if you have already downloaded a copy!

Note that the main issue with this version is loss of control after about 6 seconds of stable, sustained VTOL flight.

That's just as well, since I managed to figure out what was wrong with it. Here are my findings:

First off, I went in to inspect the craft.

I found that the 4th set of VTOL engines was at an angle relative to the others. I didn't know whether that's accidental or on purpose.

Upon closer inspection, it turns out the craft wasn't perfectly symmetrical. Not by much but I just wanted to point that out, you may have missed that very easily amongst all the other parts.

Now, I checked the centres:

I'm not entirely sure but It looked like the CoG was slightly off to the left.

Nevertheless, I decided to test how it flies as it is. Here is the aftermath:

The plane itself only needs 80% thrust to go light and if you push 85 it will lift off. But it was tilting backwards. I had my brakes on since that's what I do with VTOL craft. Note that it started to roll forwards on the ground before taking off.

So I went back to SPH, turned the craft up-side down and replaced the tilted engines:

Now, I decided to check whether the Centre of Gravity and Centre of Thrust line up right. To do that, I had to place a marker in form of an antenna over the COG, as it would shift forwards when I removed the jets:

It looks like you did a pretty good job lining them up - although I think my engine placement was a bit off in relation to the original, I'll let you have the credit for the good work

And success! It flies straight now. Don't overdo the throttle, keep it around 80-85% mark and you will be fine. Engines do overheat easily but there isn't much to be done about that. As an added bonus, I added some lights for myself (They aren't in the craft file though, so you don't need any other mods)

Finally, I also added a new action group that activates only the rear-facing jets. Reason for that is, when you activate the jets, they need to spool up but when you deactivate them, they just drop dead straight away and cut all thrust. To avoid falling when transitioning between VTOL and Plane modes, you can now press 3 and then 1.

I wanted to sub a craft file but I can't seem to find the option for it.. Hold on.

EDIT:

Here's a gitHub download link:

https://github.com/GROOV3ST3R/Craft/archive/master.zip

Edited May 16, 2013 by GROOV3ST3R

[TelluriumCrystal]

That's just as well, since I managed to figure out what was wrong with it. Here are my findings:

First off, I went in to inspect the craft.

I found that the 4th set of VTOL engines was at an angle relative to the others. I didn't know whether that's accidental or on purpose.

That was intentional. It was one of the things I tried on that version to counter the upwards lift (it didn't work, for obvious reasons).

Upon closer inspection, it turns out the craft wasn't perfectly symmetrical. Not by much but I just wanted to point that out, you may have missed that very easily amongst all the other parts.

Now, I checked the centres:

I'm not entirely sure but It looked like the CoG was slightly off to the left.

That might be what is causing the instability I was encountering. Every time I test it, it begins to tip in that direction shortly before loosing control.

Nevertheless, I decided to test how it flies as it is. Here is the aftermath:

The plane itself only needs 80% thrust to go light and if you push 85 it will lift off. But it was tilting backwards. I had my brakes on since that's what I do with VTOL craft. Note that it started to roll forwards on the ground before taking off.

Yep, thats what was wrong with that version. I have since fixed the forward movement and tilting issues.

So I went back to SPH, turned the craft up-side down and replaced the tilted engines:

Now, I decided to check whether the Centre of Gravity and Centre of Thrust line up right. To do that, I had to place a marker in form of an antenna over the COG, as it would shift forwards when I removed the jets:

It looks like you did a pretty good job lining them up - although I think my engine placement was a bit off in relation to the original, I'll let you have the credit for the good work

That was actually a good idea, I never thought to flip the plane over (yes, I painstakingly positioned those VTOL engines with it right side up ). Also, very handy trick for keeping the COG when removing the rear engines.

And success! It flies straight now. Don't overdo the throttle, keep it around 80-85% mark and you will be fine. Engines do overheat easily but there isn't much to be done about that. As an added bonus, I added some lights for myself (They aren't in the craft file though, so you don't need any other mods)

Hmm, so if it flies now then it must have been those panels on the left engine that were causing the issue. I must have forgotten to turn on symmetry when I put them there.

Finally, I also added a new action group that activates only the rear-facing jets. Reason for that is, when you activate the jets, they need to spool up but when you deactivate them, they just drop dead straight away and cut all thrust. To avoid falling when transitioning between VTOL and Plane modes, you can now press 3 and then 1.

Yes, I did that with the new version as well. 1 starts the main engines, 2 shuts them off; 3 starts the VTOL engines, 4 shuts them off. And of course delete shuts everything off and deploys the emergency parachutes.

I wanted to sub a craft file but I can't seem to find the option for it.. Hold on.

I noticed that too. It seems that the attachment system is down right now, hence why I used mediafire.

Thanks for all your help! I'll see if I can't get it working myself now.

[GROOV3ST3R]

Sure thing Try the craft I posted with the last post. It flies very well, it's a good plane. I think it must have been the tilted engines causing the main problem with flipping over. It works pretty well now though And I too fixed the symmetry.

Glad to hear that it is all working for you now anyway

On the side:

Here is a pic of one of my VTOL crafts:

Hopefully, it will give you some inspiration - you can make really weird and wonderful planes that fly pretty good as long as you balance them right. And also, keep it as simple as it can be

Edited May 16, 2013 by GROOV3ST3R

[TelluriumCrystal]

Glad to hear that it is all working for you now anyway

Actually it, well, kinda is. After further testing I think I have found the issue – KSP's strange aerodynamics don't like purely vertical VTOL operation. It becomes perfectly stable while moving forwards slightly, but any purely vertical movement causes it to act almost as if it was stalling, with the wings dragging it to the left or right. I might record a video of it, because it's hard to describe. Here, try to download the new craft file and fly it straight up, with no forwards movement at all, and you'll see what I mean.

I don't suppose there is a way to get around this issue? The main reason I wanted it to be capable of VTOL was so I could land it safely in the water, or in tight spaces. I can't do that if it is moving forwards.

[GROOV3ST3R]

Well, actually, the problem isn't as bad as you think. The plane is fairly cumbersome and difficult to fly, but that does not mean it's not good for the cause.

I would like to point out that at altitude tests, around 10ks above sea level the plane requires an INSANE angle of attack which slows it down a lot - and you are using high-altitude engines for the plane. I would suggest you replace the high-altitude turbofans with basic jets as they perform better at low altitudes.

And you can make the plane stationary and hover it quite easily. If you can catch the moment where it is almost stationary and lock it with ASAS, then the whole thing becomes childs play.

As for gaining altitude with vertical thrust - yes, that is a problem. It's basically the same if you place wings vertically on your plane - the game's dynamics are very crude, it's best to have wings facing in the directions they were meant to be facing

Still, to actually take off and start gaining altitude without moving you only need to increase the throttle a little bit. Don't floor it because that will make it tricky (or even impossible). Besides, you can hover it and once you take off, just swing around and switch to plane-mode.

Here is a version I modified:

I was trying to do a water landing but I splashed down too fast and broke off all the engines xD

Still, here's the craft file. https://github.com/GROOV3ST3R/Craft/archive/master.zip

I changed the action groups so now group one toggles turbofans and group 2 toggles vtol engines.

It's lighter and a bit more nimble. Only needs 6 vertical engines now and it should be more fuel efficient in the long run as the previous one was too heavy for it's own good.

EDIT:

Just managed to complete a successful water landing.

the trick was to keep moving at about 26m/s whilst slowly gliding down with vtols on 85% and then at around 30 odd meters, pull the nose up and kill the remaining speed and VERY SLOWLY glide down to the surface - slowly as in less than 1m/s in vertical speed and less than 5m/s horizontal speed. I'm sure that you can vtol with this plane anywhere if you just practice

Edited May 16, 2013 by GROOV3ST3R

[TelluriumCrystal]

Ah, ok. So it's too big then... I guess I can try to trim off the two outer bodies and lighten it up a bit. I'll take a look at your craft too, but only if I get stuck (I like trying to figure stuff out on my own ).

Also, here's the intended flight plan, and why I needed those high-altitude engines:

This thing is supposed to be my way of retrieving kerbals from their landed spacecraft and returning them to the KSC, even if I have to fly halfway across the world to get them (hence the absurd fuel load). I need to be able to descend from around 1 km using only vertical thrust, and preferably without any sideways movement in order to land in nearly any location, and this means I have to be able to come to a complete stop mid-air using VTOL engines and then slowly descent. It certainly won't be easy...

Edited May 16, 2013 by Thrfoot

[GROOV3ST3R]

Well it won't be easy, but it can be easily done. I made a craft with 22 parts that can circumnavigate Kerbin practically twice on one tank. I could make a VTOL version of it But it is pretty small and light compared to this plane. That's the problem with KSP, it doesn't take overweight loads too kindly...

I suppose you could haul Kerbals around the world using this plane but with a few tweaks such as more lift and radial ram intakes for even higher altitude flight. You should fly around 25-30km for really low drag and increased efficiency.

Try this one:

https://github.com/GROOV3ST3R/Craft/archive/master.zip

I have modified it now, so that it has more landing gear and some control surfaces in the rear. It's pretty stable and can be easily dropped into water - if you are careful

But I did find that when taking kerbals on EVA, they get stuck on the roof of the capsule. I don't think they like B9 command pods or even parts as they don't want to get up and walk Maybe it needs more ladders.

Edited May 16, 2013 by GROOV3ST3R

[bsalis]

This thing is supposed to be my way of retrieving kerbals from their landed spacecraft and returning them to the KSC -snip-

As an alternative you could drop them off to a space station. Then scoop them up to bring down in a spaceplane once the station is full. That would be easier I think.

This one is an 11 seater...

[AngelLestat]

Look, I also did a b9 craft with vtol, it works very nice.

You can see more images from different approachs here:

http://postimg.org/gallery/56mt7b3e/