Finally SSTO Success

[Bluegobln]

I've been trying to successfully fly and afterwards orbit an SSTO for the last day or two, probably 8-9 hours into it and had no success until this morning. Bloody things always, always seem to tumble or have runway issues, lack fuel or are too heavy for their wings. I tried iterating on designs but most of the time it made more sense to scrap the whole thing rather than try to adjust it, they were so far off.

I even started using my nemesis... FAR aerodynamics mod. I've had maaaaaany issues in the past with this, but for in atmosphere flight with wings I figured I would rather have realism than bang my head against the wall any more. Perhaps my planes have come a long way since then and I might have success in the old model, but well...

I'm doing OK now. Finally.

And who would have thought, bigger is better? I was trying to build an SSTO PURELY to ferry up one Kerb at a time, going small every time because I thought it would be more efficient for an atmospheric craft with a rocket strapped on the back. This thing (probably in part thanks to the huge Sabre engines in B9's pack) gets to 100km orbit with roughly 1/3rd its fuel empty (about 1200 / 1700), and with 3 engine options including the nuclear inline which gets great mileage of course. Oh, and a cargo bay. That means many Kerbs + fuel. O.o

Flying her in now, hitting the atmosphere I forgot I needed to put the fuel in the front to keep from going in backwards. Also I have horrible aim and was off target for the space center by a bit, but hey, Mach 2 all the way home right?

*Crashed and burned at the runway* Well... to be fair, I've never done that part before and set down rather hard.

Edited November 24, 2013 by Bluegobln

[Corw]

But what you actually wanted is this?

[Bluegobln]

Yes. Just an orbit capable small plane that can hold 2 Kerbals. I must have made 20 or more that looked similar to that (and yet often different as well). It was important that I make it myself, though I did try a few designs from the premade stuff to see how they handled.

The things I learned that solved my major hurdles:

- The rear gear should not be too far behind the Center of Mass or you wont be able to lift off.

- Landing gear needs to be straight... and I mean STRAIGHT. You can't place it on a non-straight surface even, and rotate and hope its straight, because it can still be off by a fraction of a degree and cause the plane to lurch and roll on the runway during takeoff. I now plan landing gear as part of the design, from the start, because with bad gear you never even get to see if it flies properly.

- Center of Lift needs to be behind the Center of Mass, further behind if you want to go very fast.

- The most sure fire way to make a plane more stable (as in avoid having it tumble once you're airborne) is to have an extended tail out behind the main wings by quite a bit with horizontal winglets or stabilizers. If you don't have this many designs that are otherwise good will fail. It is good if you use FAR to set these far aft wings as the pitch control and ensure that your main wings are NOT.

Note: I am unsure why the plane I managed to make that worked, actually works. It seems to be at some kind of balance point and I dare not attempt to change it, even if I might improve its flight and stability.

I guess I will be building a smaller craft now.

[Andrew Hansen]

Well, I guess I'm not the only one who figured out that bigger was better for making SSTOs. I made an ion-powered SSTO very similar to a one

. I actually got it into orbit once, but could not repeat the results again. Then I installed the B9 Aerospace pack, and by using two large SABRE engines on the ends of the largest wings available and the HL fuselage system, I got into orbit very easily. It was an amazing SSTO.

By the way, that one you have pictured in your original post is pretty beautiful! I almost thought you were using Lack Luster Labs for a while.

[inigma]

Smaller actually can be better. This can hold two. It can undock from a station at 120km, land VTOL in the ocean or on the KSC helipad, and fly back up and re-dock with said station; without refueling.

http://forum.kerbalspaceprogram.com/threads/59426-SSI-Neutron-Class-Shuttlecraft