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I finally pulled off and SSTO!


Asmosdeus

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This is my first, and so far only, plane of any sort. Managed to get it into orbit within an hour of deciding I wanted to build one, though I may have overdone the air intakes, I don't gain much from those last few intakes.

It is so far only technically reusable, as I haven't managed to land it without knocking something off, though that's almost definitely a limitation of the pilot and not the design.

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I haven't managed to land it without knocking something off, though that's almost definitely a limitation of the pilot and not the design.

Actually, looking at your picture I'd say it's likely because of your design as well, although skill can help mitigate this.

The biggest problem with the flat "pancake" design is that there's very little holding it all together. Two adjacent tanks will hold onto each other a little bit, but any sharp shock (like, say, a hard landing) will cause it to come apart at the seams, and if you're sticking a half-dozen tanks next to each other there are many possible points of failure. This applies to wings as well, but the main stress on landing is on the tanks linked to the landing gear, so at the very least you should reinforce that connection as much as possible. The solution, as always, is MOAR STRUTS. If you go back and look at my Sleazy Weasel design on the first page, this is a big part of why I went with the "thick wing" design; inside the wing are struts connecting the upper and lower wings to each other and to the fuel tanks, so the wings can actually take quite a bit of bumping before breaking. Likewise, there are struts linking the engine fuel tanks to the central fuselage at four points, so it's extremely stable to shocks. So I'd suggest adding more struts, to bolster your structural strength, if you're continually breaking apart upon landing.

Also, I highly recommend installing the Flight Engineer mod. One of its more useful bits is that in "Surface" mode, it separates your velocity vector into horizontal and vertical components, and tells you altitude above the local terrain instead of just the pressure altitude. This makes it much easier to make a soft landing, as you can zero out your vertical descent much more accurately. (It also makes landings on Gilly much easier, since the navball won't auto-shift into surface mode if you're landing on one of the more elevated points.)

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Actually, looking at your picture I'd say it's likely because of your design as well, although skill can help mitigate this.

I like the thicker designs to be honest, I'd really like to do something like the Venture Star (flying wing shuttle design). This was just a first pass to experiment with how high/fast I'd get with a given amount of thrust and air intakes.

As for skill vs design, the first landing missed the runway by about half a continent, and the second one barely overshot the runway. The only technical problem with landing seems to be that the slightest bit of roll causes one wingtip or the other to hit the ground, at which point the Very Bad Stuff Ballet Dance Troop comes out to perform. The rear landing wheels are actually attached to the wing about half way between the center stack and outer stack rather than to the outer stacks to angle the nose up a bit on the runway which cut my required airspeed to launch in half. Moving the rear landing gear to just outside the outer stack would probably help the wingtip problem, but might cause me to start seeing the kinds of problems you're describing.

As for KER, I modded my base command pods to automatically include it, I just never got around to doing the same for the spaceplane pods.

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As for skill vs design, the first landing missed the runway by about half a continent, and the second one barely overshot the runway.

I never bother trying to land on a runway. I usually just aim for some flat bit of terrain, although I've landed on the sides of mountains before when they just happened to be in the right spot. As long as your wheelbase is wide enough, it's just not an issue, although there can be bumps in the terrain that throw you around at just the wrong moment if you're not careful with the brakes.

Now, when they get around to adding more terrain features (like bringing back trees) then it'll become more important to land in the right spot. But for now, just land wherever's convenient.

The only technical problem with landing seems to be that the slightest bit of roll causes one wingtip or the other to hit the ground, at which point the Very Bad Stuff Ballet Dance Troop comes out to perform.

Rule number two of SSTO Club: turn on the Avionics package as soon as you leave the runway, and then leave it on for the rest of your flight. That keeps rolling under control, since you can better fine-tune your profile to stay level. When you're more experienced you might turn it off before major maneuvers, but it's still good to leave it on the rest of the time. This might depend on how many control surfaces you have, though; my own planes have many flaps, so it's very easy to over-steer without the avionics. (Those extra flaps make takeoff much easier, though, and help with large turns in-atmosphere, so I won't remove them.)

The rear landing wheels are actually attached to the wing about half way between the center stack and outer stack rather than to the outer stacks to angle the nose up a bit on the runway which cut my required airspeed to launch in half.

You can get that nose angle through other means, if need be (like angling the back wheels to the sides slightly, or adding a girder between the front wheel and the fuselage); attaching the wheels to the wings is just not great for physical strength. But this can also come down to struts; if your design "flexes" when you try to take off (which is especially common if your rear wheels are too far out), then it's making it much harder to get the necessary lift on takeoff; my own design has no problems taking off, in part because of all those extra flaps I put on. (If you look closely at my plane on the first page you'd see a canard embedded in the wing's leading edge, four winglets next to the engine, two forming an A-shaped tail, two more at the wing ends, two big flaps on the wing itself, and a "skirt" of four small flaps on the body panels above and below the main fuselage. All of these help with takeoffs.)

And again, part of the problem seems to be the design; a really wide wing is far more likely to touch the terrain at even a small angle, especially if you've tucked the back wheels up between two fuselage bits. Basically, when designing a spaceplane that can take off or land without hitting terrain, you care about two angles:

1> Along the plane's primary axis, the angle between the back wheels and the aftmost bit of the plane. Effectively, this is how much your nose can go up during takeoff before you clip the engines against the ground. I'd aim for 30-40 degrees, unless you're very careful with your takeoffs. A shallower angle is too likely to clip the terrain, a sharper angle requires too much torque to take off at low speeds. It also affects landings, since it'd determine how pitched your plane can be while still touching down wheels-first.

2> Along the perpendicular horizontal axis, the angle between the side wheels and the furthest bit to the side. This is how rolled you can be on landing without clipping the wingtips. I aim for about 20-30 degrees there. There's no downside to being greater than that, but any less and you're too likely to do exactly what you've described and clip the terrain on landing.

So by attaching your rear wheels to the wings directly, you might be making angle #2 too low, especially given how wide your design is. Landing only on runways would help, of course, but even so it'd be a good idea to tweak the design to make it less fragile in this area, IMO.

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here's my first succesful attempt - the imaginatively named SSTO mk 4

it's a two seater for ferrying Kerbals from ground level to my LKO station from where they should be able to catch some sort of other vehicle to distant bases/colonies:

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It has enough fuel to make orbit and randez-vous without RCS (forgot to add any - the MK4.1 will probably have some)

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Once the mission is completed it is straightforward to land on the runway as it glides pretty well and can cruise at ~22.000 and ~1400m/s

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Anyway, it doesn't look like much but it performs really well, I'll probably be getting a lot of use out of it... especially since the station I have is basically a fuel depot with a construction arm for assembling other ships and a hab module meaning i can fully refuel it up there so coming down should leave me with enough fuel to come back up... should test this out though

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I tried to fly a SSTO spaceplane to orbit for the first time today. I didn't make it to orbit, but I got into a trajectory that reached 75,000 meters and arced almost halfway around the planet. Then I landed in the ocean and broke my plane.

But "Any landing you can swim away from..."

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I made a very simple, rocket based SSTO for my first attempt.

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Apart from sending a guy to space, it doesn't do much.

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Danfrod looks baffled that he even made it to orbit.

I had about 77 m/s left to return.

I then decided to stick it on my 50 ton launcher, despite it only being half that, and attempt the fastest flight to the Mun challenge, which hasn't been remade yet.

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Reentry is interesting. Aerodynamically, it wants to turn tail-first. ASAS and the aero control surfaces can keep it nose-first right up until parachute deployment, if you prefer flying it that way,

Tail first, (as you did) is probably better:http://commons.wikimedia.org/wiki/File:Blunt_body_reentry_shapes.png

You don't want that hot pressure wave touching your rocket.

Edited by Tw1
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I made a rocket-only SSTO, but it can't be recovered or reused.

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If I removed all of the stuff that made it look aerodynamic, it could probably carry up a small payload and be recoverable and reusable.

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