Swan SSTO Shuttle (B9, KSPX)

[Rune]

Hey guys! Long time no see! Kidding, I practically live on the forums whether I post or not . RL just got in the way of me doing any more releases. I have been playing around with this one for a while, actually, but I found that SABRES have the gimbal ability of a turd, and so balancing this so you can blast full throttle was... let's say challenging. Without further due, here it is in all its glory:

It is short of a workhorse: 2 pilots, 2 empty passenger seats, and a roomy payload bay that has been tested to get to orbit payloads of up to 20mT. A true jack of all trades, you could say, and with more than decent looks, and all clocking in at a mere 130 parts (which was a surprise, in a ship this big and powerful).

I must say, the B9 pack produces some slick-looking crafts. In fact the shuttle itself is 100% B9 parts (except the landing gear, of course), the only use of KSPX is in the payload's RCS tank, and the other mods are completely optional (basically, navigation functions and a bit of flavour with the chatterer). You also have room in the shuttle to take the crew of the lander up in style, though you will have to fill the seats yourself (or with crew manifest). Let's see how it looks when we open the payload bay and show the insides:

Before you ask, the payload lander is a Mun-capable lander. Mun-capable as in "it can go from LKO, to the Mun surface, and back again". That will get you back to an aerobrake trajectory on fumes, though (I didn't make the most efficient landing, and therefore I had to finish the Mun escape burn on RCS), but don't worry: the shuttle itself gets to orbit with most of it's fuel left, so you can make the Munar insertion burn from a much higher orbit, or even get the whole shuttle to Munar orbit before you go down to the surface. RCS is always there as backup in case you screw up as I did (I only was lacking 20m/s!).

In fact, kerbal engineer redux says it has 1.7km/s 1km/s left in a 81x80km orbit, so I guess you could say this is Duna-capable. The main reason of that is the intake: it is seriously cheaty. I mean, I was able to keep the engines going full throttle until I was almost 50kms up! And going more than 1,900m/s (orbit). Talk about "efficient engines". Apparently version R3.2 of the B9 pack fixed it, and in response I added a boopload more intakes. Whatever the reason, you end up with 3/4ths 1/4th the oxidizer you started with (3,000 litres) (1,500l), and liquid fuel to spare (or correct inaccurate reentries to get back to KSC). And you really don't have to worry about flameouts, as long as you are in atmo, you can run on airbreathing mode. Now you have to worry a bit, but the center engines flames out first at least.

That short of takes care of the flight profile, right? Only a couple of further points to have in mind if you want to give this a go:

- The liftoff is tricky: wait till you are going more than 75m/s, then do it in one sharp pull, or you will start fluttering under ASAS and have a bad encounter with the runway. I just couldn't make the landing gear rigid enough, sorry . Still, I've managed it a bunch of times, and without letting any pieces on the runway, you have enough clearance, lift, and thrust.

-Due to the mysteries of fuel routing, it likes to start taking fuel from the payload first, so you will have to forbid that tank before you take off (or during flight). If you care about it, of course, you might also wait till you are in orbit to refuel the tank from the shuttle, and it should still be stable and not have CoM issues.

IMGUR ALBUM: (note some of the screenshots are form older versions with different wing profiles that ended up having unbalanced CoM/Thrust line issues)

http://imgur.com/a/Sfuh2

DOWNLOAD:

http://www./download/kmbb00iphi2ln60/Swan.craft

Edit: I fixed the intake situation, and trimmed down on mods of which only one, optional, part was present.

Rune. Enjoy!

Edited June 21, 2013 by Rune

[Zanis]

That Looks Amazing! The screenshots look really cool.

keep up the Good work!

[Rune]

Thanks! I do try to get the best views I can.

keep up the Good work!

And don't worry, more coming soon. Actually, do you guys want more B9 stuff?

Rune. They do look cool.

[andrew.xcbiker]

How could you fly this so high on full throttle? I've tried it and I can not fly over some 20.000m on full throttle as it starts to choke.

[Rune]

How could you fly this so high on full throttle? I've tried it and I can not fly over some 20.000m on full throttle as it starts to choke.

Really? It weirded me out that it wouldn't lose air at all as I was climbing until I got significantly over 40kms... perhaps I have an old version of the B9 pack with weird config files? I'll take a look at it. But I took away all other intakes because that one was working so well... :S

A quick look at the spaceport and my backup folder tells me that I have B9 version R 3, and the latest is B9 R 3.2. Thinking about it, it must be that the intake was badly configured in that version. The changelog mentions something about intakes, actually, but it says you shouldn't see any changes in gameplay. So much for that:

Intake stats recalculated using a different formula (factoring the root of mass / 0.01 for unitScalar, and factoring (unitScalar*sqrt(coeff))/(unitscalar+1) into the speed). Nothing changed gameplay-wise, but that will fix improper flow reporting in KSP context windows. Nope, RBM intakes never were 10 times more powerful than others, KSP lied to you. It will continue to lie about air speed though.

Sigh! I will give it a try to replicate your situation, though. I'm quite pissed I released an unusable craft if you are right... Still, the answer is clear if that's the case: MOAR INTAKES!

Rune. The perils of using mods, I guess.

[Rune]

...and indeed, the intake was broken and apparently has been fixed in the last revision. I've updated mine and it is just as you said, no way you take this to orbit if you can't climb to at least 25kms on airbreathing mode. Well, back to adding more intakes, I guess. I promise to fix the craft! Anyone in the possession of an "old" R3 B9 aerospace pack can still use it, though).

[andrew.xcbiker]

Well that's kind of a sad thing to me. I am trying to build heavy SSTO spacecraft capable of some resources or another spacecraft delivery to orbit atm and it is really hard task. So I hoped maybe your design might uncover some clues I haven't been aware of. I was wondering that maybe my ascent profile is wrong (well getting pretty high and gain speed on horizontal flight is no big science to be honest, but still). I will wait for fixed craft. The ship is a beauty

[Rune]

Well that's kind of a sad thing to me. I am trying to build heavy SSTO spacecraft capable of some resources or another spacecraft delivery to orbit atm and it is really hard task. So I hoped maybe your design might uncover some clues I haven't been aware of. I was wondering that maybe my ascent profile is wrong (well getting pretty high and gain speed on horizontal flight is no big science to be honest, but still). I will wait for fixed craft. The ship is a beauty

It'll come. It may have less of a margin in the fuel department, but with enough intakes to burn air at 25kms, and T/W greater than 0.5 with rockets, any SSTO that can stay stable can make orbit. Besides, I'm kind of forced to fix it now, right?

Rune. Tomorrow is the official "make good on your KSP promises" day.

[Rune]

...aaand a boopload of intakes later, it soars again to orbit. Problem solved! Mind the profile, though, now you have to switch to rocket power much earlier.

Thanks for pointing it out, andrew, it was an easy one to fix, and I think it is even sexier now, and it's still plenty capable for kerbin orbit.

Rune. Is slightly less embarassed

Edited June 21, 2013 by Rune