1.02 SSTO Fallacy?

[Nothalogh]

I think to many agency's in RL are too hung up on an SSTO cargo carrier instead they should just make one for people and be done with it.

This is my feeling as well, SSTO for crew transfer to LEO, and Big Dumb Boosters for cargo and fuel to LEO

[selfish_meme]

I have found that it is advantageous to ride the air-breathers as long as they are still raising apoapsis (which often means until they run out of air), even if that means losing speed as the craft climbs. You're still adding energy to the trajectory at a very favorable Isp.

I can't give rep on the mobile site but I wish I could. I was wondering the exact same thing.

[Levelord]

If you are interested I have an old 1.02 SSTM (Single Stage To Mun) vehicle using 2 RAPIERs and a NERVA.

http://forum.kerbalspaceprogram.com/threads/122688-Something-doesn-t-seem-right-here/page2

[Bloody_looser]

If you are interested I have an old 1.02 SSTM (Single Stage To Mun) vehicle using 2 RAPIERs and a NERVA.

That's exactly the 1.0.2 'wingless sausage' concept I had in mind.

[Captain H@dock]

That's exactly the 1.0.2 'wingless sausage' concept I had in mind.

Well, I don't know which spaceplane doesn't qualify as a wingless sausage then... If a plane is going to be doing close to 1500 m/s at 20,000m, it's sure isn't going to have a high aspect ratio...

At any rate, small SSTO (with rapier) are easy to do in 1.0.2 - 1.0.4 with the right flight profile. Such as the Tevelord's one, or this one (1.0.2 fuel configuration). Keep it simple, and it will accelerate quickly enough to make the 12,000 to 20,000 flight profile easy:

This takes off at 110 m/s (no need to rotate). Gear in, hold attitude until reaching 290, climb to keep speed constant until 13,000 (speed slaved pitch, concorde's style), level off and accelerate to 1100.

From there 1.0.2 and 1.0.4 differ (climb rate was differing too due to different TWR)

1.0.2: you'll soon see your speed reach 1100 with heat bars, so you get in a climb just enough to avoid them, yet enough to be climbing at 20-25 degrees with 1375 m/s by the time you're really loosing speed.

1.0.4: leveling off will make you loose quite some altitude, but on the other hand you can accelerate a lot more yet, at a slower rate. So it's up to you how you want to balance top speed (between 1400 and 1500) and angle of climb (between 20 and 5 degrees).

But in both case this design will take you to orbit with plenty of fuel (add 150 LF for 1.0.4) for rescues / tourists / crew ferrying. And it's around 20 parts.

So learn the profile that fits your version with small build first, then move onto bigger ones.

As an aside, i recently realized I've been putting my airbreaks in reverse of their designed orientation... that's due to the adapter itself being 180 flipped Good luck closing these in the real world!

[Red Iron Crown]

Another 1.0.2 design (not all that sausage-ish to my eye):

More info in this post. It's a bit over-engined but is very easy to fly.

[GoSlash27]

I've never made it with 2 LV-Ns, and there are many saying that it can't be done. 2 LV-45s work great though.

The rockets should NOT be fired based on your speed, they should be activated when your air intake hits .10 or so (around 25-30km usually) - that's the point that your jets are close to flameout.

They are mistaken, as I have done it myself. And if you're going to use a chemical rocket, I recommend the LV-909 or Poodle. You don't need high thrust in closed cycle mode, you need high efficiency.

Best,

-Slashy

[11of10]

Another 1.0.2 design (not all that sausage-ish to my eye):

https://dl.dropboxusercontent.com/u/61004449/KSP/1.0/screenshot94.png

More info in this post. It's a bit over-engined but is very easy to fly.

Is that a FAR design?

[Red Iron Crown]

Is that a FAR design?

No, stock 1.0.2 aero. Others have commented that it would probably do well with FAR's area ruling but I haven't tried it.

[steve_v]

Sure looks like it's area ruled for FAR to me, or maybe just to look cool.

Either way, nice plane

[Wemb]

Pretty sure people made turbojet SSTOs back in 1.0.2. The drag in 1.0.2 was higher, though, so you either need more engines or a modified ascent profile to punch through the transonic barrier

Yes, I have, barely - and them only by duplicating a design of Scott Manley's in his recent Career mode tutorial video - and even then, he had to post an update video showing how to fly it in 1.0.2 as it was so much harder to get it into orbit.

But, still, it does get into orbit, and enough to take a small T-400 based probe with about 1/2 of it's fuel left.

Almost no fuel left to deorbit with though, let alone for a powered flight back to the KSC - but most times I'vebeen able to land it on the coast, or even ditch it in the water without loosing too much of the craft.

Wemb

[Nich]

The best SSTOs i Have seen have hit 1450-1500 while still airbreathing

[GarrisonChisholm]

The OP is discovering the classic problem of airplane engineering. More fuel means more lift and more thrust required, which means still more fuel is needed, ad infinitum. If your airplane is underperforming, adding more fuel is usually a very poor answer to the problem.

Noted, and agreed. I ditched X-7 last night (X-Planes 3-7 began as twin/twin jet/rocket designs and all evolved into beautifully engineered ungainly monsters that got further and further from orbit) and created X-8, a simple 1 rocket- 2 jet design, which actually Did get Hyper-sonic, Did reach space, ...and once again needs about 150 m/s more to make orbit.

- - - Updated - - -

Another 1.0.2 design (not all that sausage-ish to my eye):

https://dl.dropboxusercontent.com/u/61004449/KSP/1.0/screenshot94.png

More info in this post. It's a bit over-engined but is very easy to fly.

@RIC; This is a Sweet looking ship. I am sure my issues will be solved with Rapiers, but I just don't have the tech yet, & it kills me to re-coup tourist money with a stack & capsule that turns mostly into eaten money.

- - - Updated - - -

Yes, I have, barely - and them only by duplicating a design of Scott Manley's in his recent Career mode tutorial video - and even then, he had to post an update video showing how to fly it in 1.0.2 as it was so much harder to get it into orbit.

Wemb

I tried to re-build that exact ship, but I don't think I matched its flight profile correctly, because it too only grew and grew in my hangar as I tried to correct issues. :\

[hazard-ish]

I'd recommend updating to version 1.0.4. Sure from a glance at the patch notes it may looks like SSTOs are nearly impossible due to the specific impulse of the RAPIER engines among other things being changed but one important thing to note is that the ceiling for which jet engines function is now increased! RAPIERs can still produce considerable thrust for me when traveling at high speeds even at 22km up where there is very little drag to slow me down.

I'm in the process of taking an SSTO from Kerbin to the Mun and back right now and I'll upload a video of it later on to prove it's possible. It just takes a lot of perfecting - this design has undergone 43 iterations (ignoring the several fully-fledged prototypes that came before it). I've got several tricks to help increase the feasibility of SSTOs in the stock game but I'll talking about those more once I had provide some evidence for my point.

Once the video is finished, I'll post it here and detail some of the finer aspects of the ascent profile which may help you and others when building SSTOs. I was a big an of building them in the old aerodynamics model so having to learn everything from scratch was a daunting challenge but it can be done!

Edited July 17, 2015 by hazard-ish

[Rune]

I argued to death the "SSTOs are useless in 1.02". Then went ahead and did a 25% payload fraction one, capable of carrying a Big Red. Enough proof people were just not getting the change of rules with the more realistic atmosphere and engines?

Rune. It works even better in 1.04, a tricked out version reached 33% payload ratio.

[X-SR71]

Sorry, this is 1.0.4, but I wanted to give the Ramjet some love. 2 of them and 2 LVNs. Made it to orbit of minmus. Liquid fuel only.