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SSTOs! Post your pictures here~


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Been Reading the Forums for ages and really wanted to post something.

I've been preparing for Career mode and its Costs when they come in, I wanted an SSTO and make it 100% reusable.

There is No Part Clipping, No Hidden Parts, No Air Hogging (tho I have used more Air intakes than I'd like too), and 100% stock not even MechJeb.

Haven't got names but have creatively named them versions 1 - 2.

Jet Assisted V2 - Takes 3 Kerbals to 220km and can dock up with a station at 100km from 220km.

oalrAtS.jpg

Also it Docked up with a Station

vysSYCx.jpg

(Launch is fairly easy, turn at 4km up and cut engines at 22km and go to main Rocket Motor).

Jet Assisted V1 - Takes 3 Kerbals to 300km and can dock up with a station at 100km from 220km and Spare fuel for Filling Station. *Not 100% reuseable*

7MBiQKS.jpg

(Launch is fairly easy, turn at 4km up and cut engines at 22km and go to main Rocket Motor).

Jet Assisted SAT Launcher - Takes Payload of 3.8tns (less than the 3 Kerbals version due to probe command part)

Xf3b8d5.jpg

(Launch is fairly easy, turn at 4km up and cut engines at 22km and go to main Rocket Motor).

Sat Launcher with Payload of 2.8tn

BS7DOdP.jpg

And the Cargo in Orbit at 230km

mID3I76.jpg

Link to my Dropbox below with all my current ship designs in there.

https://www.dropbox.com/sh/4ggwlw317rrsx5b/CZg3YOw4kO

Steam Screenshot folder of my current ships and mistakes

http://steamcommunity.com/profiles/76561197980444911/screenshots/?appid=220200

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I used to build spaceplanes. Then I realized that wings are mostly aesthetic elements whose real function is to make the SSTO harder to fly. Now my crew shuttle looks like this:

laythe_lander.jpg

Even without intake spamming, it can reach LKO without any difficulty. The design is still far from perfect, because the ship needs to refuel to carry the crew to the orbit of Mun or Minmus.

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Cargo One.

SSTO, lifts a decent sized cargo into orbit, the centre of mass sits in the middle of the payload area so it flies as well full or empty and on any fuel load. Over 1 Kms delta v once in orbit. Many liberties taken with air intakes.

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2 for the jets

3 for the rockets

Go like the clappers at 30 Km, by 33Km with the intakes at about 25% run the jets and the rockets together and push the apoapsis out far enough so that you can coast up to circularisation.

Disclaimer: I do all this with Mechjeb.

https://www.dropbox.com/s/djz9fmilf38rcoj/Cargo%20One%20NMJ.craft

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Another large cargo/passenger spaceplane. I think it carries 39 kerbals and has alot of cargo space for 1.25m parts. Not sure what its range is though.

.../snip

OH snap I love that piggy back idea and also the double huge wing .. I may need to build one like this.

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I used to build spaceplanes. Then I realized that wings are mostly aesthetic elements whose real function is to make the SSTO harder to fly. Now my crew shuttle looks like this:

http://www.cs.helsinki.fi/u/jltsiren/stuff/laythe_lander.jpg

Even without intake spamming, it can reach LKO without any difficulty. The design is still far from perfect, because the ship needs to refuel to carry the crew to the orbit of Mun or Minmus.

Please see my post on the previous page and lets talk about putting our head together on a design. I am stuck at the 4.5tn cargo lift. want to hit 12-18tns, and I think we might be able to do this!

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Please see my post on the previous page and lets talk about putting our head together on a design. I am stuck at the 4.5tn cargo lift. want to hit 12-18tns, and I think we might be able to do this!

The key thing for jet-powered SSTO lifters is that you should think them as VTOL spaceplanes without wings. I built a quick proof-of-concept lifter from the crew shuttle by removing RCS, adding a probe core, batteries, and solar panels, and attaching the payload with a decoupler.

ssto_lifter.jpg

In this configuration, launch mass is 16 tonnes, payload mass is 4.6 tonnes, and the dry mass of the lifter is around 6 tonnes. A good launch profile is probably similar to the crew version: go straight up until 10 km, turn to a 45-degree pitch until 15 km, then 30 degrees until 17.5 km, then 20 degrees until 20 km, and finally accelerate with an angle of attack that keeps the vertical speed between 10 m/s and 30 m/s. When the turbojets run out of air at around 32-33 km, airspeed should be over 1900 m/s, which is pretty close to orbital velocities. Things didn't go that smoothly above 20 km during my first test flight, but I still got the ship to a 123x120 km orbit with something like 200 m/s of delta-v left.

That design should scale up pretty well by adding more engines and more fuel.

Edited by Jouni
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The Cargo Twelve.

A bigger brother to the Cargo One, capable of lifting a big orange tank into LKO with 1Km/s Delta V to spare.

Outsize cargo bay allows for unusually sized cargo.

Takes half an hour to get into orbit.

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Edited by Fellow314
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K, I'm going to copy here what I've just written somewhere else, but I think it applies perfectly. Call it a piece of my design philosophy on SSTO design:

Hahaha. That's because you are looking at it from a completely different perspective! You are basically saying to treat SSTO's like rockets, not planes. And I'm more of the idea that planes are planes, and rockets are rockets, and you can SSTO both of them.

Let me explain further: you can't fly on four engines (or however many), because you don't have enough wing. But you could always fly on thrust, of course, if you add more engines. That is perfectly valid, and the logical extreme is forgetting about the SPH and moving your SSTO business to the VAB. Perfectly doable, and very easy as you say, just make it get off the pad with enough rocket delta-v. But that way you are building rockets, not planes. And there's also the fact that engines have considerable weight, especially airbreathers, and wings you could consider free, mass-wise.

So what happens if you build a proper plane, with T/W considerably lower than 1? You need lots of wings. That makes it big. But it has much less engines than a T/W>1... which makes it lighter! Much, much lighter. Basically what that means is that you will always get a bigger mass fraction in a SSTO if you spam wings, not engines. Now that extra payload to space could be extra fuel (so, more range), or plain payload (so a smaller SSTO for the same job). Always consider that while the climb might be long, the extra aviation fuel you consume is probably peanuts compared to the total mass of the SSTO. And even my slowest ascents never takes more than 15minutes, 10 of which I spend websurfing while I climb over 10,000,.

Now the other thing is rocket takeover speed. But I won't get more into that, because basically it is a function of intakes, the more you have, the faster you go, and the less rocket delta-v you need. As simple as that. So considering these points, my requirements for a winged SSTO that aspires to do more than a VTOL SSTO ever could (be it range or payload) would be about balancing these two factors: as little engines and as much wing as I can, while still being able to climb at 10,000m, and on the other hand, as many intakes as I need to get fast enough for my rocket delta-v to get me to orbit. As you can see, the less engines you take because you can use wings, and the less rocket fuel you use because of intakes, the lighter you vehicle becomes. And that means payload fraction to orbit, ultimately.

Of course, that also means that by the time you get to orbit, if you can refuel, all that airbreathing equipment becomes useless and a dead weight. But a smaller dead weight that if it was composed of engines!

I should also mention how the faster you transition to rocket power the less rocket T/W you need, that is another weight saving, but it is a little besides this particular point, and I've said it enough times. Bottom line: fast climbs to orbit come at a price, and a heavy one.

Rune. In engineering, everything is a trade.

Rune. So yeah, VTOL SSTOs are easy. They are also very inefficient.

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Rune. So yeah, VTOL SSTOs are easy. They are also very inefficient.

A bit inefficient maybe. I wouldn't call 30% payload fraction to LKO very inefficient. Especially when the design is something you can quickly hack together, using only one intake per jet engine.

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A bit inefficient maybe. I wouldn't call 30% payload fraction to LKO very inefficient. Especially when the design is something you can quickly hack together, using only one intake per jet engine.

You are counting engines as part of the payload right? Because with a few kilograms in wings, you can take that same 4.5mT crew capsule (your real payload) to orbit on a single turbojet/RAPIER (half the powerplant), and with enough intakes I can also make it under half the takeoff weight. That's what I mean by very inefficient.

Rune. Note I also add: perfectly valid. I even add that it is much easier, and makes for a faster while playstyle.

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You are counting engines as part of the payload right? Because with a few kilograms in wings, you can take that same 4.5mT crew capsule (your real payload) to orbit on a single turbojet/RAPIER (half the powerplant), and with enough intakes I can also make it under half the takeoff weight. That's what I mean by very inefficient.

In that example, the payload was the command pod and the attached parts (4.6 tonnes), and the launch mass was 16 tonnes, so the payload fraction was a bit less than 29%. I already started building a bigger model that turned out to be quite ridiculous.

ridiculous_lifter.jpg

The lifter scaled up quite well and behaved pretty much the same as the smaller model during the ascent. With 16 turbojets and a Skipper, the launch mass was 115.3 tonnes, including payload. That got the 36.2-tonne payload into a 125x121 km orbit, with about 350 m/s of delta-v remaining. The total mass will increase by a few tonnes, when I add landing gear and some parachutes for parachute-assisted powered landing.

I'm not going to use more than one intake per engine, unless the drag model changes to take the air flow from intakes to engines into account. This means that I have to switch from jets to rockets when the airspeed is around 1950 m/s, or risk going into spin and losing at least 50 m/s.

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I figured something out today.

I've been building SSTO's where the fuel tanks are as close to the middle of the craft as possible so when the fuel drains the weight doesn't shift too much making the aircraft balanced like it was when full.

This is the thing I learned... if you have a fuel tank at the front of the craft, and a fuel tank in the rear of the craft, then having the front fuel tank feed the engines on the left of the craft, and the rear fuel tank feeding the engines on the right of the craft.. the drain will be even front and back in turn not making weight shift as it drains.

If you take this design principal it means you can have space in the middle of the craft for taking things as cargo.

: D

Edited by KissSh0t
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I figured something out today.

I've been building SSTO's where the fuel tanks are as close to the middle of the craft as possible so when the fuel drains the weight doesn't shift too much making the aircraft balanced like it was when full.

This is the thing I learned... if you have a fuel tank at the front of the craft, and a fuel tank in the rear of the craft, then having the front fuel tank feed the engines on the left of the craft, and the rear fuel tank feeding the engines on the right of the craft.. the drain will be even front and back in turn not making weight shift as it drains.

If you take this design principal it means you can have space in the middle of the craft for taking things as cargo.

: D

Thats what I've been doing for all my crew and Cargo SSTOs

EhFRkK6.png

gPirnpg.png

Works very well

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K, I'm going to copy here what I've just written somewhere else, but I think it applies perfectly. Call it a piece of my design philosophy on SSTO design:

Rune. So yeah, VTOL SSTOs are easy. They are also very inefficient.

I would add to that the need to make the distinction between a short range heavy lifter and a long range light lifter. If you are pushing a high payload fraction into LKO then a >1 TWR is best. Those 30min ascents scrub out huge amounts of fuel in the form of atmospheric drag which you don't benefit from if you are only popping up into lower orbit. With a long range craft you do get the payback with more fuel during space flight having burnt the jet fuel on the way up.

I also think basic jets are an awesome way to get your SSTO TWR up. Just when your basics cut out your turbos are starting to peak in the thrust department. Also, you don't need many turbos at the top of the atmosphere, they tend to be dead weight. I've seen too many designs that use too many just for getting through the lower atmosphere when basic jets are lighter, more fuel efficient and have more thrust(and just as useless as extra turbos at high altitudes).

My rule of thumb is about 0.8TWR of turbos, 0.5TWR of basics and 0.2TWR on nukes.

EDIT: These numbers are ground level engine outputs.

Edited by O-Doc
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