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Can't get this SSTO in orbit even if it reaches 2200 m/s at 35000 m!

Fire-Dragon-DoL
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GoSlash27

GoSlash27

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Thanks slashy, that's a very good suggestion. I'll be trying a new SSTO this evening.

One note, remember that some wings have been chosen for design purposes.

Are there any table with most efficient wings?

I had one around here somewhere, but that was for .25. I'm due to make a new table for .90, so I guess that'll give me something to do today.

Your most efficient wings are (in order)

#1 the strake

#2 the structural "D"

#3 the old swept wing.

I'll put together a new table that compares all the wings.

Best,

-Slashy

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herbal space program

herbal space program

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Posted
You made the poor Kerbal sit on the outside of the plane the entire way there?! You monster! :sticktongue:

The problem with your IMG tags is that you've stuck URL tags inside them - remove those and it'll work.

What I remember is that all you need to do is put IMGUR ... /IMGUR in brackets around just the last part of the image URL, but that doesn't seem to work for me now. Would you mind posting an example of the correct syntax for Imgur images? The forum FAQ is clear as mud about this. Thanks!

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Anquietas314

Anquietas314

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What I remember is that all you need to do is put IMGUR ... /IMGUR in brackets around just the last part of the image URL, but that doesn't seem to work for me now. Would you mind posting an example of the correct syntax for Imgur images? The forum FAQ is clear as mud about this. Thanks!

IMGUR tags are for albums - i.e. multiple images. You use IMG ones (directly on the URL, without additional URL tags) to make a single image appear.

That is, [ IMG ]http://i.imgur.com/napMQ9Z.jpg[ /IMG ] without spaces to do this:

napMQ9Z.jpg

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Fire-Dragon-DoL

Fire-Dragon-DoL

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IMGUR tags are for albums - i.e. multiple images. You use IMG ones (directly on the URL, without additional URL tags) to make a single image appear.

That is, [ IMG ]http://i.imgur.com/napMQ9Z.jpg[ /IMG ] without spaces to do this:

http://i.imgur.com/napMQ9Z.jpg

This looks more like a big antenna, rather than a spaceplane, lol

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herbal space program

herbal space program

Posted
Posted
IMGUR tags are for albums - i.e. multiple images. You use IMG ones (directly on the URL, without additional URL tags) to make a single image appear.

That is, [ IMG ]http://i.imgur.com/napMQ9Z.jpg[ /IMG ] without spaces to do this

Thanks! I see the problem now. if you cut and paste the link from the address bar at Imgur, it pastes it with implicit URL tags rather than as just text. BTW, in my defense I must admit that I never actually flew that ship to Laythe :blush:, although based on deltaV and its performance in other scenarios, there's no reason it shouldn't make it. I was going to use it as a Laythe lander for the Jool 5 mission I just completed, but the part count turned out to be too high together with everything else.

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numerobis

numerobis

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Posted
Are there any table with most efficient wings?

You want the wing with the most lift / mass, generally. So you can just compare in the SPH quite easily.

The control surfaces (elevon, delta-deluxe, and av-r8) have much more lift than do the other lifting parts ("lifting surface" and "winglet"). Whereas lifting surfaces max out at a 25-degree angle of attack, control surfaces max out at 90 degree angle of attack.

There's also the drag value (not listed in the SPH, you need to read the .cfg file directly), which you want as low as possible, but as I noted upstream, it's not that relevant. In 0.25, the lighter wings have less drag (two small wings have less drag than one large wing, but the same mass and lift). I think 0.90 is the same way.

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GoSlash27

GoSlash27

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Posted (edited)
The infiniglide, I understand, but how is that getting up to 28km/s? The landing can doesn't have the monoprop for that, and I don't see any other sources of fuel...

My apologies, I've side-tracked the original discussion with my little cheaty toy.

It doesn't actually require any fuel whatsoever to do what it does. The monoprop is there JIC I want to dock in orbit. Deflecting the controls will accelerate it enough to get up to over 800 m/sec. Then you "release the kraken", which is a different physics exploit that gives you free continuous acceleration by attempting to force parts to disconnect.

Back to the original subject, I'm ginning up a new wing comparison table for .90 KSP. I'll post a copy of it here when it's ready.

Best,

-Slashy

Edited by GoSlash27
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Fire-Dragon-DoL

Fire-Dragon-DoL

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^ Take another look. That's Eve :cool:

But yeah, it'll do Laythe and Duna as well. All in the same trip.

Cheating is bad :)

-Slashy

My apologies, I've side-tracked the original discussion with my little cheaty toy.

It doesn't actually require any fuel whatsoever to do what it does. The monoprop is there JIC I want to dock in orbit. Deflecting the controls will accelerate it enough to get up to over 800 m/sec. Then you "release the kraken", which is a different physics exploit that gives you free continuous acceleration by attempting to force parts to disconnect.

Back to the original subject, I'm ginning up a new wing comparison table for .90 KSP. I'll post a copy of it here when it's ready.

Best,

-Slashy

And a craft file of your cheatplane!

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GoSlash27

GoSlash27

Posted
Posted (edited)

Numerobis,

If it's not too much trouble, could you look this over for any errors?

I'm listing the wings by stats, assuming enough wings to work for 10 tonnes of spaceplane, and then calculating drag coefficients at 20* AoA.

They are dimensionless, so V and p are not considered.

Cl is assumed directly, while Dtotal is assumed as NM*sin20(Cd)

KSP .90 Wing type comparison

[TABLE=width: 500]

[TR]

[TD]Type[/TD]

[TD]Cl[/TD]

[TD]Cd[/TD]

[TD]Mass[/TD]

[TD]N@Cl=10[/TD]

[TD]Mtotal[/TD]

[TD]Dtotal[/TD]

[/TR]

[TR]

[TD]Swept[/TD]

[TD]1.6[/TD]

[TD].6[/TD]

[TD].05[/TD]

[TD]6.25[/TD]

[TD].31[/TD]

[TD].0641[/TD]

[/TR]

[TR]

[TD]Conn A[/TD]

[TD]2[/TD]

[TD].5[/TD]

[TD].1[/TD]

[TD]5[/TD]

[TD].5[/TD]

[TD].0855[/TD]

[/TR]

[TR]

[TD]Conn B[/TD]

[TD]2[/TD]

[TD].5[/TD]

[TD].1[/TD]

[TD]5[/TD]

[TD].5[/TD]

[TD].0855[/TD]

[/TR]

[TR]

[TD]Conn C[/TD]

[TD]1[/TD]

[TD].25[/TD]

[TD].05[/TD]

[TD]10[/TD]

[TD].5[/TD]

[TD].0428[/TD]

[/TR]

[TR]

[TD]Conn D[/TD]

[TD].5[/TD]

[TD].12[/TD]

[TD].025[/TD]

[TD]20[/TD]

[TD].5[/TD]

[TD].0205

[/TD]

[/TR]

[TR]

[TD]Conn E[/TD]

[TD].5[/TD]

[TD].12[/TD]

[TD].025[/TD]

[TD]20[/TD]

[TD].5[/TD]

[TD].0205[/TD]

[/TR]

[TR]

[TD]Delta[/TD]

[TD]2[/TD]

[TD].6[/TD]

[TD].1[/TD]

[TD]5[/TD]

[TD].5[/TD]

[TD].1026[/TD]

[/TR]

[TR]

[TD]Sml Delta[/TD]

[TD].5[/TD]

[TD].1[/TD]

[TD].025[/TD]

[TD]20[/TD]

[TD].5[/TD]

[TD].0171

[/TD]

[/TR]

[TR]

[TD]Strake[/TD]

[TD].75[/TD]

[TD].2[/TD]

[TD].025[/TD]

[TD]13.3[/TD]

[TD].33[/TD]

[TD].0228[/TD]

[/TR]

[TR]

[TD]Struct A[/TD]

[TD]1[/TD]

[TD].3[/TD]

[TD].05[/TD]

[TD]10[/TD]

[TD].5[/TD]

[TD].0513[/TD]

[/TR]

[TR]

[TD]Struct B[/TD]

[TD]1[/TD]

[TD].3[/TD]

[TD].05[/TD]

[TD]10[/TD]

[TD].5[/TD]

[TD].0513[/TD]

[/TR]

[TR]

[TD]Struct C[/TD]

[TD].5[/TD]

[TD].15[/TD]

[TD].025[/TD]

[TD]20[/TD]

[TD].5[/TD]

[TD].0257[/TD]

[/TR]

[TR]

[TD]Struct D[/TD]

[TD].25[/TD]

[TD].08[/TD]

[TD].012[/TD]

[TD]40[/TD]

[TD].48[/TD]

[TD].0131[/TD]

[/TR]

[TR]

[TD]Swept A[/TD]

[TD]1[/TD]

[TD].3[/TD]

[TD].05[/TD]

[TD]10[/TD]

[TD].5[/TD]

[TD].0513[/TD]

[/TR]

[TR]

[TD]Swept B[/TD]

[TD]1[/TD]

[TD].3[/TD]

[TD].05[/TD]

[TD]10[/TD]

[TD].5[/TD]

[TD].0513[/TD]

[/TR]

[/TABLE]

So what I've done here is gone by the old rule of thumb "1.0 lift coefficient of lift for each tonne of spaceplane". I've taken enough of each wing type to meet that, and then compared how much they weigh and how much drag they make.

In the case of an SSTO spaceplane, we don't care much about a couple hundred kg in comparison to 10 tonnes of spacecraft. All we really need to worry about is drag.

So in order (lower drag is better), these are the most efficient wings for the job in KSP .90

#1 Structural D. Absolute lowest drag, but unfortunately also highest part count.

#2 Small Delta. Excellent drag, and also not too bad for part count.

#3 Connector D&E. Excellent drag, but not quite as good as the small delta for the same part count.

#4 Strake. Excellent drag, and part count is also very good. <-- My recommendation for most spaceplanes.

#5 Connecter C. Good drag, very good part count.

#6 Struc A,B, Swept A, and B. Average drag, good part count.

#7 Swept wing. Excellent part count, fair drag.

Anything below this, you really just plain should not use because they suck out loud.

The worst of the worst is the delta wing. Use anything but that!

Best,

-Slashy

Edited by GoSlash27
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numerobis

numerobis

Posted
Posted
Numerobis,

If it's not too much trouble, could you look this over for any errors?

The main thing I object to is your focus on drag. Drag can almost be ignored; even with the delta wing, you need to go about 4km/s to get lift:drag = 1; at lower speeds or with better wings, you wings are giving you much more in lift than they lose in drag.

What matters much more is the mass; wings provide net negative force around 35km when you take into account their weight, plus they're just extra mass to accelerate.

So, I rank wings by lift:mass ratio. Which has the notable advantage that you can compute it directly from the SPH info dialogs.

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GoSlash27

GoSlash27

Posted
Posted
The main thing I object to is your focus on drag. Drag can almost be ignored; even with the delta wing, you need to go about 4km/s to get lift:drag = 1; at lower speeds or with better wings, you wings are giving you much more in lift than they lose in drag.

What matters much more is the mass; wings provide net negative force around 35km when you take into account their weight, plus they're just extra mass to accelerate.

So, I rank wings by lift:mass ratio. Which has the notable advantage that you can compute it directly from the SPH info dialogs.

Gotcha and I'd like to table that discussion for the moment.

I just wanted to verify that the numbers look good before I spread this table around.

If it looks good from your house, I'm going to post it as a tutorial and then I'll explain in that thread why I disagree.

Best,

-Slashy

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Fire-Dragon-DoL

Fire-Dragon-DoL

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New spaceplane, same problem, I can't bring it out of the atmosphere.

I used ONE pair of delta wings for design purposes. The wings are extremely optimized: 29.35 lift over 29.0 weight. In theory, if I use 300 liquid fuel on jet engines, I should have 5300 delta v to spare to reach LKO and go to Laythe, I don't know if it's enough. Intakes should be enough. My best bet right now is adding another LV-N (which should not be too complex, I made it so that nothing is attached over it). As always, suggestions are accepted.

P.S. It has a docking port in the middle, not everything is fuel. I have a spreadsheet with used pieces. It uses only stockparts EXCEPT for mechjeb2.

2014-12-28_15-40-41.jpg

2014-12-28_15-44-09.jpg


[TABLE="width: 767"]
[TR]
[TD]Name[/TD]
[TD]Amount[/TD]
[TD]Lift[/TD]
[TD]Total Lift[/TD]
[TD][/TD]
[TD]Total Weight[/TD]
[TD]Total Lift[/TD]
[/TR]
[TR]
[TD]Mk2 Cockpit[/TD]
[TD="align: right"]1[/TD]
[TD="align: right"]0,60[/TD]
[TD="align: right"]0,60[/TD]
[TD][/TD]
[TD="align: right"]29,00[/TD]
[TD="align: right"]29,35[/TD]
[/TR]
[TR]
[TD]Mk2 Rocket Fuel Fuselage Short[/TD]
[TD="align: right"]3[/TD]
[TD="align: right"]0,30[/TD]
[TD="align: right"]0,90[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]Mk2 Clamp-o-tron[/TD]
[TD="align: right"]1[/TD]
[TD="align: right"]0,15[/TD]
[TD="align: right"]0,15[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]Mk2 Rocket Fuel Fuselage[/TD]
[TD="align: right"]1[/TD]
[TD="align: right"]0,60[/TD]
[TD="align: right"]0,60[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]Mk2 to 1.25m Adapter[/TD]
[TD="align: right"]2[/TD]
[TD="align: right"]0,30[/TD]
[TD="align: right"]0,60[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]Mk2 Bicoupler[/TD]
[TD="align: right"]2[/TD]
[TD="align: right"]0,20[/TD]
[TD="align: right"]0,40[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]Mk2 Liquid Fuel Fuselage Short[/TD]
[TD="align: right"]2[/TD]
[TD="align: right"]0,60[/TD]
[TD="align: right"]1,20[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]Mk2 Cargo bay CRG-04[/TD]
[TD="align: right"]1[/TD]
[TD="align: right"]0,60[/TD]
[TD="align: right"]0,60[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]Swept Wings[/TD]
[TD="align: right"]4[/TD]
[TD="align: right"]1,60[/TD]
[TD="align: right"]6,40[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]Wing Strake[/TD]
[TD="align: right"]12[/TD]
[TD="align: right"]0,75[/TD]
[TD="align: right"]9,00[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]Structural Wing Type D[/TD]
[TD="align: right"]2[/TD]
[TD="align: right"]0,25[/TD]
[TD="align: right"]0,50[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]Elevon 5[/TD]
[TD="align: right"]6[/TD]
[TD="align: right"]0,60[/TD]
[TD="align: right"]3,60[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]Structural Wing Type A[/TD]
[TD="align: right"]2[/TD]
[TD="align: right"]1,00[/TD]
[TD="align: right"]2,00[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]Elevon 1[/TD]
[TD="align: right"]0[/TD]
[TD="align: right"]0,25[/TD]
[TD="align: right"]0,00[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]Advanced Canard[/TD]
[TD="align: right"]4[/TD]
[TD="align: right"]0,70[/TD]
[TD="align: right"]2,80[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[/TABLE]

Craft file

Edited by Fire-Dragon-DoL
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GoSlash27

GoSlash27

Posted
Posted (edited)

Sorry, not following.

What do you mean when you say you "can't"?

What's happening? Is it running out of fuel, or you can't get it to accelerate on rockets? Something else?

*edit* I tried downloading and installing your craft file, but it says you have "locked or invalid parts".

*edit again* I didn't realize MJ was a "part". :blush: I've removed the references to it in my copy. Hope it works...

Best,

-Slashy

Edited by GoSlash27
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