My asymmetrical shuttle with one SRB

[Thraken]

While I have built some SSTO (single stage to orbit) planes in the past, I am usually a rocket and capsule KSP guy. This is for a couple of reasons. One is that my computer only has 4GB of RAM and an old processor, and flying a SSTO all the way to orbit can take 30+ minutes, where as rockets are much quicker. Another reason is that due to my limited experience returning a space plane from orbit, most of my SSTOs turn out to be MPTG (Multiple pieces to ground). This means that for the most part (outside of mods), I'm stuck sending three Kerbals up and down at a time.

I was never a big fan of the real life space shuttle. It took people up. It took cargo up. And it took both back down. And it was never most efficient at either. Shuttles have also been very tricky to build with KSP. Requiring lots of balancing of COM and COT, and usually throttle up and rolls to get the accent profile to work. Then there was the same problem with me not knowing the best way to return a winged craft from orbit.

With the introduction of the vector, I decided to give shuttles another shot, and I have to say I am very happy with what I came up with. It has an extremely simple accent profile (100% throttle, launch, gravity turn, and stage to orbit). It is also 100% recoverable. (or would be if the single SRB didn't drop out of physics range before reaching space) The external fuel tank gets into space on a sub-orbital trajectory, and then spins through atmospheric heating and has parachutes. The orbiter even has parachutes for poor pilots like myself. The one part that is not stock is a fuel valve release from the "smart parts" mod. This is so I can drain the fuel to decrease orbiter weight.

I present my creation to you here. It draws heavily on the MAKS, but is not air launched. I really like the asymmetrical design, with the single SRB. It doesn't do cargo. It holds 6 Kerbals. It has plenty of DeltaV for orbital maneuvers, and RCS for docking. It doesn't have enough DeltaV to make it to the Mun, but that isn't what it is designed for. I don't think I took a picture of it, but there is a MK2 docking port on the belly of the orbiter.

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Edited November 14, 2015 by Thraken

[Dman979]

Well, it's very unconventional, to say the least. I like the asymmetric design. One thing- where do you start your gravity turn? It looks like you just launch straight up, and then burn at Apo. It'd be more efficient to do a gentle turn to 0^o, so you get there at your apo.

[Thraken]

I start the gravity turn at about 200m/s. However the gravity turn is very slow until SRB sep. At that point I can adjust angle all I need for efficiency. During this accent I don't know that I brought my A-game. I was thinking about taking screen shots.

While I've played KSP since 0.21, this is my first thread.

[Thraken]

I'm not so certain it is just bad piloting skills on re-entry. I think the Vector is just too heavy. It always flips around when I get into atmosphere. Has anyone else built a space plane with a Vector on the back?

[Red Dwarf]

I think I can see a good way to manage this. The Vector is almost certainly too heavy for such a small orbiter, so it might be possible to move it onto your external tank. Since it's recoverable, you won't lose any funds in career mode, and you'll make your orbiter easier to handle on descent. It might mess with the center of thrust, though I'm sure the Vector would be able to compensate. Definitely do some tinkering!

Edit: Oooh, also, taking the Vector off the orbiter frees up a position for flyback engines in case you don't nail the descent corridor.

[Rune]

[quote name='Thraken']I'm not so certain it is just bad piloting skills on re-entry. I think the Vector is just too heavy. It always flips around when I get into atmosphere. Has anyone else built a space plane with a Vector on the back?[/QUOTE]

When balancing shuttle-like stuff, you have to remember the only time it's supposed to fly, it's [I]empty[/I]. Check the CoM/CoL with empty tanks, you most likely will have to have the wings quite a ways backwards. A V or T tail would help putting some lift further back, too.


Rune. Original stacking, BTW. Edited November 18, 2015 by Rune

[Porkjet]

Hah that's nice!

[Thraken]

Thanks for the ideas! I'll do some tinkering. I'll probably play with the wings and tail first (probably a V tail), and if I can't nail it there, I can try moving the Vector to the external fuel tank.

One good think about this design is that it has given a huge boost to my experience bringing winged craft back from orbit.

(BTW, glad you like it PorkJet!)

[Mikki]

Amazing shape! :)

[Thraken]

[quote name='Rune']When balancing shuttle-like stuff, you have to remember the only time it's supposed to fly, it's [I]empty[/I]. Check the CoM/CoL with empty tanks, you most likely will have to have the wings quite a ways backwards. A V or T tail would help putting some lift further back, too.[/QUOTE]

Rune, you were spot on! I moved the canards from the front of the orbiter to the tail. It ends up being more of a "+" shape more than a "T", but it flies (glides) like a dream now. Amazing how you could diagnose that with just a few pictures.

I also limited the thrust on the SRB to 70% which makes the initial gravity turn easier.

So with a few tweaks, I'm really liking this and getting better at bringing a winged craft down from orbit. Thanks for the help everyone, and I'll try to upload some more pictures soon.

[Rune]

[quote name='Thraken']Rune, you were spot on! I moved the canards from the front of the orbiter to the tail. It ends up being more of a "+" shape more than a "T", but it flies (glides) like a dream now. Amazing how you could diagnose that with just a few pictures.

I also limited the thrust on the SRB to 70% which makes the initial gravity turn easier.

So with a few tweaks, I'm really liking this and getting better at bringing a winged craft down from orbit. Thanks for the help everyone, and I'll try to upload some more pictures soon.[/QUOTE]

You are very welcome! After so long doing this, you pick quite the talent to eyeball these things.


Rune. The only way to learn is to try... And most often fail.