3.75m capable cargo bays

[Christian Gerefalk]

Now that 3.75m parts are stock and a lot of interesting stuff people want to take into space are 3.75m (KSPi stuff, 3.75m fuel tanks etc) I think 3.75m capable cargo bays are a good idea.

Easiest though least interesting way to achieve it is just to provide an alternate scale of some of the HL parts:

rescaleFactor = 1.15

Not that much larger, a simple adapter like the HL->2m one shouldn't look that out of place.

Not enough room to clear most radial attachments, might need to be a tiny but larger to accommodate RCS thrusters etc.

132.25% scale in modo (1.15^2 = 1.3225) not sure why rescaleFactor = 1.15 is actually 132.25% but nvm. Cylinder is 3.75m.

Dimensions before scaling:

Horizontal: 3.2476m Vertical: 3.75m

Dimensions after scaling:

Horizontal: 4.295 Vertical: 4.9594

Mass: 5.44*(1.15^3) = 8.27356 (I assume that's correct?)

What do you guys think? Obviously a bit of a cheap cheat to just re-scale existing parts, but making a new fuselage system from scratch is pretty involved I imagine.

Could have an overall smaller diameter if round or closer to round than the HL shape though.

Though I admit HL spaceplanes area already pretty out there, a near on 5m diameter spaceplane is pretty... ambitious, though B9 is futuristic, and well 5m spaceplanes looks sensible next to HX stuff XD

[Leonardo Valeri Manera]

First off, in the general sense, I have no problem with not being able to lift what's essentially the KSP equivalent of the Saturn V's main stage into orbit in the hold of a spaceplane.

Secondly, personally, I'm against rescaling. I know Artyom is as well; we currently have (afair) 1 rescaled part in B9, the SABRE intake, and even there'd I'd like to go in and give it a unique model.

Thirdly, there are some major limitations you're not considering:

• The runway isn't long enough to take off

• The engines aren't big enough to take you up without using silly amounts of 2.5m SABREs

• The landing gear is too short to rotate off the runway. Its already very close to impossible with S2W

• The ladders aren't long enough to reach the ground from a cockpit that high off it.

Now, assuming you still want to ahead with it you have 2 options:

• Make a tweakscale-based extra for B9.

• Make a whole new fuselage system - this could possibly be integrated into B9 itself.

You will need:

• New cockpit

• New adapters

• New landing gear

• New engines

• New intakes

• New ladder

• A kerbtown-made runway that's at least 6 kilometers long

• Most likely new wings, HW21 wont cut it as a single option, too inflexible, you're have to rescale the panels at a very minimum to have a flexible wing system that doesn't require pWings. Generating new lift numbers is non-trivial, though you can have my spreadsheet for that, I suppose.

Even if you do the rescales you will have to redo:

• Mass for all parts

• Connection strength for all parts

• New suspension values

• New IVA, or at the very least a new adapter

• New wing values

• Still a new ladder model, rescaling existing ones will make it wider.

• Plus the runway.

This is a non-trivial undertaking that will most likely take several weeks to do well. Think very hard if you want to tackle it.

[Christian Gerefalk]

I'll take that as a "no" :P

But yeah if you put it that way, being able to launch a saturn 5 in an SSTOSP is kinda... errm... well... nvm. I'll blame scott manley on this one.

[Leonardo Valeri Manera]

I'm not shooting you down on principle, but apart from the non-trivial work of all the supporting parts needed on top of the fuselage (SAS, RCS, Cockpit, ladder, engines, intakes, wings, landing gear) the kicker is the runway.

KSP parts have a much, much higher inert mass fraction (when it comes to fuel tanks) and are generally much heavier than the real-world alternatives, so even though the jet engines are ludicrously powerful by comparison, you still need very long takeoff runs on fully-loaded SSTOs.

If you've ever tried making an HL or S2W SSTO in the stock drag model - and B9 needs to work in the stock drag model - you'll know what a major pain in the ass it is taking off with a full cargo. Now imagine you're carrying 50% more dead weight.

[Christian Gerefalk]

Hmm yeah tricky I imagine, a skilled player like scott could probably get it to work but the average guy that just found the game + B9 in stock aero would probably only manage to make a very complicated submarine launching system with superfluous wings.

[Leonardo Valeri Manera]

Scott uses FAR, so his takeoff runs are a lot shorter and he needs way less engine.

Every 2.5m SABRE is 6 tons of weight you have to carry around.

[Leonardo Valeri Manera]

On hold until we get a longer runway or more a convenient way to create one.