payload with wings to orbit?

[xendelaar]

I'm trying to get a 15t winged payload (it's a duna space plane) into orbit, but when i start my gravity turn ever so gently, the rocket starts spinning like crazy.

I've tried putting the payload on top with huge fins and control surfaces on the bottom of the rocket but that didn't work. I also tried a nasa shuttle like approach with the payload on the side of the rocket but i had terrible time evening out the centre of mass and thrust. So that didn't work either. I don't have the tech yet to build a fairing that is large enough for this plane with delta wings so that's not a solution either.

My question is.: how do you guys get winged payloads into orbit?

Edited October 1, 2015 by xendelaar
Changed post to anwered

[Superfluous J]

I'd do a shuttle-type design but with 2 main stacks, one "above" and one "below" the plane. Then I'd turn the plane 90 degrees so you're not launching "to the right" but pitching up and down.

Imagine the (US) Space Shuttle, with the engines on the orange tank instead of the shuttle, and another orange tank attached to the shuttle on the cargo bay doors, with engines of its own. Oh and lots of struts

Do you have RCS Build Aid installed? I suggest it for tweaking Center Of Mass on non-symmetrical craft.

[KerikBalm]

Strap stuff on radially to your space plane:

*those are non-stock electric atmospheric engines on the plane

Fully stock.

[Alshain]

Planes that take off from the runway do not have to be SSTO. I have a few planes that drop tanks on their way up. It's still cheaper than dropping rocket engines.

Or you could take it up with jet engines and drop those.

[Laie]

I'm trying to get a 15t winged payload (it's a duna space plane) into orbit, but when i start my gravity turn ever so gently, the rocket starts spinning like crazy.

The simple solution: even more and bigger wings at the bottom of the rocket. You say that doesn't work, I say you should use moar and bigger fins.

The not-quite-as-simple solution: move the Center of Mass forward of the spaceplane. It can possibly even look quite elegant.

(https://en.wikipedia.org/wiki/MAKS_%28spacecraft%29)

[GluttonyReaper]

Another, less elegant solution is to put even bigger wings on the launch vehicle. Not really weight-efficient, but it works.

[xendelaar]

Hi guys,

Thanks for the replies.

@Horseman: do you mean you have the plane positioned vertically and you add a large rocket (radially) on the belly and back of the plane, turning it into a plane sandwich?

Alternatively, I was thinking of putting a large rocket inline of the space plane and adding giant wings on the bottom of the rocket, turning the rocket into a giant vertical spaceplane. The spaceplane sandwich sounds much more appealing though!

I haven’t tried the RCS aid mod yet. I will install it when I get home from work.

@Kerikbalm: Making a proper spaceplane carrier with air breathing engines is also a good idea , but I want to keep it as a last resort because my SPH isn’t able to contain more than 30 parts at the moment and I don’t have the dough to upgrade this facility. I’m doing a “10% sliderâ€Â-hard- career run of the game and I made some bad decisions along the way, almost bankrupting me, haha. It makes the game much more interesting though! Your Duna-plane looks really nice! Is the wide wingspan not a problem when you try to land it on the red planet? What is the stalling speed of the vessel and what is its weight? I looks really light.

I also like your modular concept of the lifter-planes. I bet you can use them for any payload!

@Alshain: I’m not looking to make a SSTO per se . I just want to get a payload with large wings into orbit so I can then get it to Duna… By any means necessary. Any way is better than my current way… which is nonexistent! XD

@everybody: Tonight, I will first try the Spaceplane sandwich. If that fails I will try to make a giant vertical spaceplane and if that doesn't work out, I will try Kerikbalms modular spaceplane-lifter concept. Thanks for the amazing ideas. Off course, any additional ideas are highly appreciated!

I will upload some pictures of the designs I come up with.

- - - Updated - - -

@Gluttany reaper and laie. I guess we came up with the same idea but you guys were a bit faster. As you can see in my previous post: it's on the to do list. thanks for the input!

[GoSlash27]

xendelaar,

5thHorseman is talking about this:

Definitely an easy way to go, as the wings stabilize the stack instead of destabilizing it.

Best,

-Slashy

[Superfluous J]

@Horseman: do you mean you have the plane positioned vertically and you add a large rocket (radially) on the belly and back of the plane, turning it into a plane sandwich?

Yup. And I love the term

[xendelaar]

Hi slashy. That's exactly what i had in mind (after reading 5thHorseman's post). Why are the top parts (the orange tanks) of both rockets wider than the bottom parts (t400)? That seems counterintuitive.

[RCgothic]

Is "Upgrade your Duna spaceplane to be a Kerbin Spaceplane and refuel in orbit" a valid suggestion?

[KerikBalm]

@Kerikbalm: Making a proper spaceplane carrier with air breathing engines is also a good idea , but I want to keep it as a last resort because my SPH isn’t able to contain more than 30 parts at the moment and I don’t have the dough to upgrade this facility.

Well, that's not a problem, launch them vertically.

You think this launched horizontally?

Not when the payload has that massive X at the back to give it a wide base for tailsitting landings....

That thing launched vertically, and pitched over. That was 1.02, I'm not sure how much I'd need to change it to work in 1.04. The reduced jet thrust shouldn't be too much of a problem, because it already had a static TWR <1... I added recoverable SRBs to it to get it to lift off vertically and pitch over.

I do plenty of vertical launches from the runway, by just rotating stuff in the SPH.

I launched that one from the runway, so I'd get 100% recovery of the boosters rather than 98% from having them land near the launchpad.

Here's the boosters I used to loft that thing vertically with enough oomph to get it into horizontal flight

In 1.04, the SRBs would burn longer, so that should help the weaker jet thrust for the takeoff... I might need to add more LF for 1.04 since jet Isp was reduced.

That one already barely made orbit, FYI, I made use of the poodle on the payload, and transfered fuel into it from the strap on SSTOs, so the payload was released fully fueled.

If you're willing to send up a 2nd refueling flight, its even easier to get a spaceplane payload to orbit in this way (less mass to lift/ the spaceplanes tanks and engine become the launchers tanks reducing the drag of adding more tanks and engines)

I’m doing a “10% sliderâ€Â-hard- career run of the game and I made some bad decisions along the way, almost bankrupting me, haha. It makes the game much more interesting though!

Sounds too grindy to me... but I've got nearly 7 mill of funds in my career mode now. I do revert, I do quick save...developng my spaceplanes would be an expensive proposition without revert to fix mistakes on TO (normally, if I get them off the runway and past mach 1, I get them to orbit), and it also allows me to try much moe aggressive maneuvers to land wthout a go around, to deorbit without waiting another orbit, etc... and of course there are kraken attacks... I'll never give up revert and quickload.

Your Duna-plane looks really nice! Is the wide wingspan not a problem when you try to land it on the red planet? What is the stalling speed of the vessel and what is its weight? I looks really light.

Well, the landing gear are under the engine pods, so the wide wingspan is coupled with a wide gearbase, so its fine... stopping is the problem, because the taildragger configuration means I cant use any breaking power on the forward landing gear (nose over, also massive yaw torque if both wheels aren't contacting the ground equally). I have a pair of airbrakes on it... they don't do much on Duna (in 1.02... 1.04 should be even worse). So most braking power is from the drogue chutes and the main chutes on the wing.

Stall speed of course varies depending on altitude... as you can see in the screen shot... with 1.02 physics settings, and my engine parameters at that time... it couldn't even fly much faster than 90 m/s... which is still much better than a rover.

It was made similar to a design I used pre 1.0, before thrust scaling for atmospheric pressure, that was actualy STOVL... it has a pair of lift fans, main parachutes at the CG on the mainwing... so it could pop chutes and drop vertically, controlling descent rate with the lift fans.

The lift fans gave it nearly 1:1 Duna TWR, and it could take off in a short distance. That much thrust was the only way to get reasonable flight speeds with the pre 1.0 drag model.

Now my mod is more conservative (although I haven't changed the stats for 1.04 balance)... and the lift fans did very little... dead weight almost.

I did use the rotate tool (not available on the previous .24 or .25 incarnation) to have the lift fans angle forward with the intent of having themgive it some forward velocity too. Using them in horizontal flight allows decreased AOA, and provides a horizontal component, thus increasing speed... but if I were designing them again, I'd get rid of them completely to make it lighter weight.

Also... the two "main chutes" don't drop it at a slow enough rate, even using the lift fans, so vertical landing is out... I'd delete them in a newer version, and put a single one at the tail for extra braking power.

In summary, were I to make it again:

- Airbrakes-> gone, the radial drogues stay and serve the same purpose anyway

- liftfans-> gone, not worth the mass and drag

- wing mainchutes -> removed, singe braking one at the tail to deploy when touched doen

- ox-stat spam... reduced, using the 2x4 peice from the asteroid day mod... lowers part count.

Obviously, the chutes need to be repacked after each landing, otherwise it will probably come apart on the ground, leaving it wrecked (but the kerbals alive), so an appropriately skilled engineer needs to be on every flight. Its got a probe core so a scientists can also go along and maximize science returns before flying back to the surface hab/return vehicle... post 1.1 I'll need a pilot to be in controlling range for that to work... :/

Ahh... found a pic of my old .24 duna solar plane:

I was using NEAR in that save... that one could get to ~300 m/s on the electric fans (I should have nerfed them harder)... it also carried a nuke so it was a STOVL SSTO on Duna.

I launched it in a very similar manner, with strap on rapier pods to get it to LKO... except in that version, the rapier pods just deorbited and came back on chutes, because there was no "fund incentive" to recover them at the runway.. so the pods were not fully fledged SSTO spaceplanes as in my post 1.0 incarnation.

No, the rover could not fly... it could glide...sort of... to enable a little bit of aiming during reentry, to save a bit of driving... once it touched down, it wouldn't go airborn again... and it had to land on chutes, with retrorockets.

My new rover is much smaller because I just need a scientist, not a mobile lab, to reset goo and mat bays.

It also is a 2 seater, with an engineer to repair wheels, and repack chutes... which is important, because the retrorocket system was overengineered, and the rover is capable of vertical takeoff under rocket thrust and ascending over a kilometer... quite a fun little rover actually... if it gets going too fast going down hill and I know a crash is imminent... fire vertical lift rockets, pop chutes, retroburn before landing.

(its got a claw to easily latch onto a fuel source and refuel, or transfer fuel from something to something else... 1 FL-T200 tank at a time)

- - - Updated - - -

Is "Upgrade your Duna spaceplane to be a Kerbin Spaceplane and refuel in orbit" a valid suggestion?

Then you're stuck with dead weight of atmospheric oxygen using engines, and/or low Isp rapiers...

And far more fuel capacity you want, because the dV requirements are less for Duna.

Edited October 1, 2015 by KerikBalm

[GoSlash27]

Hi slashy. That's exactly what i had in mind (after reading 5thHorseman's post). Why are the top parts (the orange tanks) of both rockets wider than the bottom parts (t400)? That seems counterintuitive.

xendelaar,

That was just a way to get the thrust centers as close to the center of mass as possible while leaving room for the payload and keeping the stack short.

It's not actually required, just convenient in some cases.

Best,

-Slashy

[moogoob]

xendelaar,

5thHorseman is talking about this:

http://i52.photobucket.com/albums/g13/GoSlash27/KSP/Nikky/Nikky1_zpsjhbbwzuz.jpg

Definitely an easy way to go, as the wings stabilize the stack instead of destabilizing it.

Best,

-Slashy

I used a similar launching method for the Nastybird (see link in sig) - it's very stable and the wings actually do help maneuverability

[Tex_NL]

The simple solution: even more and bigger wings at the bottom of the rocket. You say that doesn't work, I say you should use moar and bigger fins.

The not-quite-as-simple solution: move the Center of Mass forward of the spaceplane. It can possibly even look quite elegant.

https://upload.wikimedia.org/wikipedia/commons/thumb/0/0a/%D0%9C%D0%BD%D0%BE%D0%B3%D0%BE%D1%86%D0%B5%D0%BB%D0%B5%D0%B2%D0%B0%D1%8F_%D0%B0%D0%B2%D0%B8%D0%B0%D1%86%D0%B8%D0%BE%D0%BD%D0%BD%D0%BE-%D0%BA%D0%BE%D1%81%D0%BC%D0%B8%D1%87%D0%B5%D1%81%D0%BA%D0%B0%D1%8F_%D1%81%D0%B8%D1%81%D1%82%D0%B5%D0%BC%D0%B0_-9%D0%90-10485-_%28%D0%9C%D0%90%D0%9A%D0%A1%29.png/800px-%D0%9C%D0%BD%D0%BE%D0%B3%D0%BE%D1%86%D0%B5%D0%BB%D0%B5%D0%B2%D0%B0%D1%8F_%D0%B0%D0%B2%D0%B8%D0%B0%D1%86%D0%B8%D0%BE%D0%BD%D0%BD%D0%BE-%D0%BA%D0%BE%D1%81%D0%BC%D0%B8%D1%87%D0%B5%D1%81%D0%BA%D0%B0%D1%8F_%D1%81%D0%B8%D1%81%D1%82%D0%B5%D0%BC%D0%B0_-9%D0%90-10485-_%28%D0%9C%D0%90%D0%9A%D0%A1%29.png

(https://en.wikipedia.org/wiki/MAKS_%28spacecraft%29)

You're absolutely correct. I've done things similar to this with average sized shuttles very often. But it can also be done with small or even insanely big.

Edited October 1, 2015 by Tex_NL

[eddiew]

Moar. Boosters.

(Couldn't be bothered trimming off the other panels, sorry.)

[xtoro]

You can use a launch assist like my Atlas jetpack to get you up to speed and high up before doing your orbital insertion.

The use the FMRS mod to land the Atlas, and then switch back to your plane and go into orbit.

Link to my post with craft download

You could also fly the Atlas back to KSC and recover it so there are no lost parts and the only fund cost is fuel.

Edited October 1, 2015 by xtoro

[xendelaar]

Thanks again for all the advice.

I just made my latest transport vehicle named "Buns of steel". I used 5th horsmans design to bring the Maudib to Duna. My first design was a direct success. I will use the other designs in the future for more fuel efficient ways of transport. The reusable transfer crafts of Kerikbalm and xtoro look really neat!

Here's a small visual mission report of my Plane Sandwich

Javascript is disabled. View full album

[Superfluous J]

IMO, the simplest/most efficient way to do this would be a nice Mk2 SSTO that refuels in LKO. Don't re-invent the wheel.

I'll accept most efficient, but you and I have different definitions of "simple."

[xendelaar]

IMO, the simplest/most efficient way to do this would be a nice Mk2 SSTO that refuels in LKO. Don't re-invent the wheel.

You mean a SSTO that transfers the payload to orbit? Or do you mean one vehicle that goes to duna in one stage? The plane is going to perform all kinds of missions on duna so I don't want to carry all that "SSTO dead weight" on that planet.

on a side note: I just arrived at my fuel base and my darn Claw won't attach to my spaceplane LOL. I guess I have to design a new refuelling base :S

[xtoro]

Sometimes you have to smack into the claw with a bit of speed and not slow like you would if you were docking.

[GoSlash27]

You mean a SSTO that transfers the payload to orbit? Or do you mean one vehicle that goes to duna in one stage? The plane is going to perform all kinds of missions on duna so I don't want to carry all that "SSTO dead weight" on that planet.

xendelaar,

Option #3: Build an SSTO that can just get to Kerbin orbit. Refuel it there, then proceed to Duna.

Best,

-Slashy

[xendelaar]

Sometimes you have to smack into the claw with a bit of speed and not slow like you would if you were docking.

I figured it out: The claw doesn't clamp on to wings and my nose is covered with delta wings. I had to skim the claw from the side. It's not very elegant, but it works! I'm sciencing the sh!t out of Duna as we speak.

@Slashy, perhaps I'm going to do option 3 when I get the RAPIER tech. Now I'll just do my thing with the plane sandwich. It's so cool there are so many possibilities to get from A to B. Man... I really love this game haha.

Edited October 1, 2015 by xendelaar

[GoSlash27]

@Slashy, perhaps I'm going to do option 3 when I get the RAPIER tech. Now I'll just do my thing with the plane sandwich. It's so cool there are so many possibilities to get from A to B. Man... I really love this game haha.

Yeah, just throwing it out there. If it were me I wouldn't bother putting jet engines on a Duna SSTO. Or sometimes- jet engines that are overweight and inefficient.

I think the sandwich lifter is the way to go.

Best,

-Slashy

[xtoro]

Electric propellers on a Duna plane FTW!