Looking for someone who actually knows what they're doing to fix my SSTO

[Fireheart318]

So I've been working on this SSTO for quite a while now ('bout tow hours at this point) and I just can't get it into space. I reckon I could if I could just break the sound barrier (and keep accelerating). Can someone who actually knows what they're doing give me some help? It's not that I'm bad at planes, I've been building planes for about a year and a half now. I just suck at SSTOs. In this case, it's probably aerodynamics, but I've done everything I can in that department; the nose used to be a shielded docking port, the nose cones clipping into the cargo bay were occluded intakes, and the wings were 45 deltas instead of slim deltas

Here, take the .craft file - https://kerbalx.com/crafts/30392/

Also, you might want to try a few of my other crafts, just for fun

Edited June 24, 2017 by Fireheart318

[Alshain]

You have way too much drag.  I can't push it much further over mach 1 even in a dive, even switching the center engine for a Whiplash wasn't enough.  I got to 10,000m and pushed into a 15 degree dive with full engines (whiplash configuration) and still couldn't breach 350 m/s.  That is your max velocity.

Mk2 parts are notoriously draggy and you have a bunch of em all clipped together.  On top of that, you have a lot of unused nodes hiding in there.  The way stock drag mechanics work, unused node are drag, even at the back.  You have the bicouplers clipped together where the center engine is and as far as I can tell, nothing on them.

EDIT: Actually you have an unused node at the front because you clipped the cockpit inside an adapter.  That counts as a flat front as far as KSP is concerned.

Edited June 24, 2017 by Alshain

[Spricigo]

The "no pictures,  no clicks"  motto applies for many people that would provide the help you seek.  

Personally, also like to know what the intended purpose of the craft is.  How much cargo/crew to where? 

[Alshain]

6 minutes ago, Spricigo said:

The "no pictures,  no clicks"  motto applies for many people that would provide the help you seek.  

Personally, also like to know what the intended purpose of the craft is.  How much cargo/crew to where? 

It has no cargo and only one crew.  It's just a really really big, really draggy plane to carry one Kerbal.  I could fix it but it would be redesigning it from the ground up.  I mean, I hate to discourage, but this design isn't going to work.

[Spricigo]

1 hour ago, Alshain said:

I could fix it but it would be redesigning it from the ground up.  I mean, I hate to discourage, but this design isn't going to work.

 

Sadly, I agree. Better restart than fix

If the OP is interested I have This one laying around. 4 passengers,  single stage to orbit and back. No docking port or hatch (I use Crew Cabin Hatch mod)  and somewhat low powered rockets (several options available to 'fix it',  RAPIERs ,  Thuds,  Terriers ,  Darts  or even extra Sparks).

Of course I'm not the only on e that have spaceplanes available on KerbalX.  You may download a few,  experiment then to discover what kind of design you like and only then try to apply the ideas on a  design that suits your needs /style 

 

[bewing]

I have to agree a lot with Alshain. MK2 is very draggy. Every part you add to the plane adds mass and drag -- very bad things! Reduce part count. Put draggy stuff at the very back if at all possible. An engine can only accept air from one intake. 3 engines means 3 intakes max -- however, one intake can feed many engines. The shock cone makes the bestest nosecone because it has high heat resistance, very low drag, and it's an intake! Very important to put a little incidence on your wings. Don't carry too much fuel! The prettier you make your plane, the slower it will be.

So I redesigned your plane to reduce part count and weight and drag. This one makes it to orbit really easy.

[Fireheart318]

6 hours ago, Spricigo said:

The "no pictures,  no clicks"  motto applies for many people that would provide the help you seek.  

Personally, also like to know what the intended purpose of the craft is.  How much cargo/crew to where? 

It's a prototype "detatchable SSTO". Once in orbit, the front part of the craft detaches and becomes its own orbiter while the "lower stage" stays in LKO waiting for the cockpit to return

4 hours ago, bewing said:

So I redesigned your plane to reduce part count and weight and drag. This one makes it to orbit really easy.

Thanks but this kinda defeats the point (from what I can see). The cockpit assembly was going to detach from the main craft and work as an orbital vessel, which was why I went with MK2. Why is MK2 so draggy anyway?

Either way, thanks for the advice and I'll try to implement it. Also, why are the wings separated like that? Shouldn't they be right up next to the fuselage?"

[bewing]

32 minutes ago, Fireheart318 said:

It's a prototype "detatchable SSTO". Once in orbit, the front part of the craft detaches and becomes its own orbiter while the "lower stage" stays in LKO waiting for the cockpit to return

You've got to mention important details like that when asking for design help.

I could probably modify this design to do that. Actually, it's pretty easy. Swap the LF and LFO MK1 tanks. Put a pair of docking ports between them. Put a pair of thuds or twitches on the sides. Done. Needs some solar and batteries, though.

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Why is MK2 so draggy anyway?

Because god made it that way.

Quote

Also, why are the wings separated like that? Shouldn't they be right up next to the fuselage?

The wings are attached to the sides of the MK2 part. Which is wider than the MK1 parts. It makes no difference at all to the aerodynamics if there is a gap between the body and the wings.

 

Edited June 24, 2017 by bewing

[bewing]

This looks nothing like your ship, but it does what you want -- so maybe you can get some ideas from it.

craft file: https://pastebin.com/raw/SvLab1wE

 

[GoSlash27]

What Alshain said. You have unused nodes and parts clipped into non- nodes. This defeats the game's "occlusion", resulting in large flat surfaces exposed to the airflow. Your ship looks clean, but actually has the aerodynamics of a brick wall. That's why you can't get past Mach 1.

HTHs,
-Slashy