Stearwing D45 to SSTO

[Jestersage]

No, it's not a question of "How to make it into SSTO", because the answer is "replace the Mk-2 cockpit with an inline, at least one shockcone, and the converter; fly 10 degree above horizon until desired AP"

My question is (aside from why stock didn't just do that) more on the various configuration, namely, the droptank.

For some reason, I found it the most efficient if I stick with the 1.0.5 jet fuel drop tank, instead of the 8 tordial droptank or equivalent length of oscar. Also, is it confirm that the Mk2 to 1x2.5 coupler will have less drag than the 2x?

Edited December 6, 2016 by Jestersage

[bewing]

56 minutes ago, Jestersage said:

aside from why stock didn't just do that

Because the stock vessels are intentionally created with flaws for you to fix, and for you to learn to improve the designs.

56 minutes ago, Jestersage said:

For some reason, I found it the most efficient if I stick with the 1.0.5 jet fuel drop tank, instead of the 8 tordial droptank or equivalent length of oscar.

Because the jet fuel tank is an MK1 part, and MK1 parts have the lowest drag.

 

[AeroGav]

18 hours ago, Jestersage said:

Also, is it confirm that the Mk2 to 1x2.5 coupler will have less drag than the 2x?

I don't think there is much in it, actually.   I did some testing in 1.1.x and this

was less than twice the drag of this

 

Of course, in the face of the insane drag all mk2 fuselage parts are saddled with, this is like using a napkin to mop up a wine stain on the Titanic.

I think the main issue with the engine staging rationale is that the Whiplash's thrust multiplier drops to 3 by mach 4.5 (1350 m/s), whereas the  RAPIER stays above that out to mach 5.5 (1650 m/s). .

Because orbital velocity is 2300 or so, the RAPIER version only needs to add another 650 m/s delta-v to get there, the Whiplash needs 950 m/s to make low kerbin orbit.   True, the staged version only carries 1 ton of engines to orbit (two terriers)  while an SSTO would have four tons if using dual RAPIER, also the Delta V of the Terrier is over 10% better.     So why not use RAPIERs as your disposable engines and get the best of both worlds?  Cost, that's why  - the RAPIER is three times as expensive.

I suppose if you're going beyond LKO, the lower dry mass of the two stage design can overcome the  disadvantage of it's lower starting velocity.  But the Stearwing doesn't have the delta v to do this,   that means swapping to nukes.

I'm thinking of making a gameplay challenge,  fix the Stearwing D45.

I tried it, two or three hours later we have this - 

https://kerbalx.com/AeroGav/Stearwing-D45N

^^ Like the original, it has additional economy class seating in the cargo bay.  I've added some lighting for their comfort, and also you'll notice the thoughtfully placed RTGs to keep them warm,  as well as the gigantic reaction wheel massage to ward off DVT. 

 

Unfortunately, once again, i've struggled (failed miserably)  to keep the stock look , despite my attempt at forward sweeping the wing.  I decided to radially mount the jet engines, because  

a) it doesn't mess with the CoM  the way hanging them off the back does

b) when staged off, the radial engines are gone, nil drag.  rear mounted ones prevent you putting cones on the back of your terriers, so they will suffer an open node penalty (ok, I'm acting like Howard Huges over this, given what we know about mk2 fuselages.   It needs to have flush rivets!)

c) you can run both sets of engines together , once you're committed to leaving the atmosphere there's no reason not to .

Packs a fierce amount of delta V though.   

 

Edited December 6, 2016 by AeroGav